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ACbrrr monitoring

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  ACbrrr monitoring Don Y <blockedofcourse@foo.invalid> - 2017-03-30 14:31 -0700
    Re: ACbrrr monitoring Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-03-30 14:49 -0700
      Re: ACbrrr monitoring Don Y <blockedofcourse@foo.invalid> - 2017-03-30 15:02 -0700
        Re: ACbrrr monitoring Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-03-30 15:16 -0700
          Re: ACbrrr monitoring Don Y <blockedofcourse@foo.invalid> - 2017-03-30 15:45 -0700
    Re: ACbrrr monitoring Neon John <no@never.com> - 2017-03-31 18:08 -0400
      Re: ACbrrr monitoring Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-03-31 15:33 -0700
        Re: ACbrrr monitoring Don Y <blockedofcourse@foo.invalid> - 2017-03-31 15:53 -0700
          Re: ACbrrr monitoring Neon John <no@never.com> - 2017-03-31 20:36 -0400
            Re: ACbrrr monitoring Don Y <blockedofcourse@foo.invalid> - 2017-03-31 19:22 -0700
              Re: ACbrrr monitoring Neon John <no@never.com> - 2017-04-01 12:18 -0400
                Re: ACbrrr monitoring Don Y <blockedofcourse@foo.invalid> - 2017-04-01 11:17 -0700
                  Re: ACbrrr monitoring Neon John <no@never.com> - 2017-04-02 12:26 -0400
                    Re: ACbrrr monitoring Don Y <blockedofcourse@foo.invalid> - 2017-04-02 14:42 -0700
      Re: ACbrrr monitoring Don Y <blockedofcourse@foo.invalid> - 2017-03-31 16:06 -0700
        Re: ACbrrr monitoring Neon John <no@never.com> - 2017-03-31 20:53 -0400
          Re: ACbrrr monitoring Don Y <blockedofcourse@foo.invalid> - 2017-03-31 19:38 -0700
            Re: ACbrrr monitoring krw@notreal.com - 2017-03-31 23:11 -0400

#454274 — ACbrrr monitoring

What can I learn (in absolute and relative terms) from monitoring
the temperature and pressure in high and low side coolant lines
to the ACbrr's evaporator coil?

E.g., obviously, they can tell me of compressor failures/losses
in the extreme case.  And, for "constant" environmental conditions
can give me an idea as to how the system is degrading, over time.

But, is there anything beyond a "check engine light" that
could be gleaned from that instrumentation?

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#454279

Den torsdag den 30. marts 2017 kl. 23.31.47 UTC+2 skrev Don Y:
> What can I learn (in absolute and relative terms) from monitoring
> the temperature and pressure in high and low side coolant lines
> to the ACbrr's evaporator coil?
> 
> E.g., obviously, they can tell me of compressor failures/losses
> in the extreme case.  And, for "constant" environmental conditions
> can give me an idea as to how the system is degrading, over time.
> 
> But, is there anything beyond a "check engine light" that
> could be gleaned from that instrumentation?

you can draw the PH diagram and get all sorts of info

https://www.ohio.edu/mechanical/thermo/Intro/Chapt.1_6/Chapter4c.html

somewhere I have a program I made for a guy that does refrigration systems
that could plot the cycle on a PH diagram for various refrigerants in realtime given the pressures and temperatures

-Lasse

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#454286

On 3/30/2017 2:49 PM, Lasse Langwadt Christensen wrote:
> Den torsdag den 30. marts 2017 kl. 23.31.47 UTC+2 skrev Don Y:
>> What can I learn (in absolute and relative terms) from monitoring
>> the temperature and pressure in high and low side coolant lines
>> to the ACbrr's evaporator coil?
>>
>> E.g., obviously, they can tell me of compressor failures/losses
>> in the extreme case.  And, for "constant" environmental conditions
>> can give me an idea as to how the system is degrading, over time.
>>
>> But, is there anything beyond a "check engine light" that
>> could be gleaned from that instrumentation?
>
> you can draw the PH diagram and get all sorts of info
>
> https://www.ohio.edu/mechanical/thermo/Intro/Chapt.1_6/Chapter4c.html

Thanks, I'll dig through that.

> somewhere I have a program I made for a guy that does refrigration systems
> that could plot the cycle on a PH diagram for various refrigerants in realtime given the pressures and temperatures

But how would the user -- or, an AI acting on his behalf -- interpret
this information to provide "meaningful" information to the user:
- "Your compressor is about to fail"
- "Your refrigerant is low"
- "You are expecting more performance from your system than it can deliver"
- "Clean your evaporator/condenser coils"
etc.

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#454289

Den fredag den 31. marts 2017 kl. 00.03.01 UTC+2 skrev Don Y:
> On 3/30/2017 2:49 PM, Lasse Langwadt Christensen wrote:
> > Den torsdag den 30. marts 2017 kl. 23.31.47 UTC+2 skrev Don Y:
> >> What can I learn (in absolute and relative terms) from monitoring
> >> the temperature and pressure in high and low side coolant lines
> >> to the ACbrr's evaporator coil?
> >>
> >> E.g., obviously, they can tell me of compressor failures/losses
> >> in the extreme case.  And, for "constant" environmental conditions
> >> can give me an idea as to how the system is degrading, over time.
> >>
> >> But, is there anything beyond a "check engine light" that
> >> could be gleaned from that instrumentation?
> >
> > you can draw the PH diagram and get all sorts of info
> >
> > https://www.ohio.edu/mechanical/thermo/Intro/Chapt.1_6/Chapter4c.html
> 
> Thanks, I'll dig through that.
> 
> > somewhere I have a program I made for a guy that does refrigration systems
> > that could plot the cycle on a PH diagram for various refrigerants in realtime given the pressures and temperatures
> 
> But how would the user -- or, an AI acting on his behalf -- interpret
> this information to provide "meaningful" information to the user:
> - "Your compressor is about to fail"
> - "Your refrigerant is low"
> - "You are expecting more performance from your system than it can deliver"
> - "Clean your evaporator/condenser coils"
> etc.

it's been a while and I only know enough about refrigeration to be dangerous ;)

I think this has more details and examples 

http://sporlanonline.com/literature/education/5-200.pdf

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#454293

On 3/30/2017 3:16 PM, Lasse Langwadt Christensen wrote:
> Den fredag den 31. marts 2017 kl. 00.03.01 UTC+2 skrev Don Y:
>> On 3/30/2017 2:49 PM, Lasse Langwadt Christensen wrote:
>>> Den torsdag den 30. marts 2017 kl. 23.31.47 UTC+2 skrev Don Y:
>>>> What can I learn (in absolute and relative terms) from monitoring
>>>> the temperature and pressure in high and low side coolant lines
>>>> to the ACbrr's evaporator coil?
>>>>
>>>> E.g., obviously, they can tell me of compressor failures/losses
>>>> in the extreme case.  And, for "constant" environmental conditions
>>>> can give me an idea as to how the system is degrading, over time.
>>>>
>>>> But, is there anything beyond a "check engine light" that
>>>> could be gleaned from that instrumentation?
>>>
>>> you can draw the PH diagram and get all sorts of info
>>>
>>> https://www.ohio.edu/mechanical/thermo/Intro/Chapt.1_6/Chapter4c.html
>>
>> Thanks, I'll dig through that.
>>
>>> somewhere I have a program I made for a guy that does refrigration systems
>>> that could plot the cycle on a PH diagram for various refrigerants in realtime given the pressures and temperatures
>>
>> But how would the user -- or, an AI acting on his behalf -- interpret
>> this information to provide "meaningful" information to the user:
>> - "Your compressor is about to fail"
>> - "Your refrigerant is low"
>> - "You are expecting more performance from your system than it can deliver"
>> - "Clean your evaporator/condenser coils"
>> etc.
>
> it's been a while and I only know enough about refrigeration to be dangerous ;)

Ditto.  And, the HVAC guys tend to only react to things that are
sorely out of kilter, catastrophic failures, etc.  I suspect none
of them would know how to interpret "real time" data over the course
of the system's lifespan.

> I think this has more details and examples
>
> http://sporlanonline.com/literature/education/5-200.pdf

Thanks, I see a few "sample scenarios" illustrated, therein.  I just
want to make sure I've come up with the right cost-benefit tradeoff for
the instrumentation before "closing" the system.

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#454490

On Thu, 30 Mar 2017 14:31:35 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

As an engineer who has operated an industrial/commercial refrigeration
business on the side for most of his career,  I'll take a shot.

>What can I learn (in absolute and relative terms) from monitoring
>the temperature and pressure in high and low side coolant lines
>to the ACbrr's evaporator coil?

I have no idea what "ACbrrr" is but I'll guess that you're speaking of
the HVAC on a modern car.

The answer to your question is essentially "absolutely nothing".  An
extreme lack of refrigerant will manefest itself as little to no
cooling but you'll probably have already gotten a CE light by then.

If you are low on refrigerant you can't just "dump in a blow-off can"
and hope for the best as in the old days.  The system should be
drained, evacuated and charged to the nameplate weight of refrigerant.

The reason I said "absolutely nothing" is that a modern car may have
all or part of the following:

computer controlled expansion valve
computer controlled or not evaporator back pressure regulating valve
(GM parlance: POR valve)
computer controlled or not variable displacement compressor
computer controlled variable speed condenser and evaporator fan.
high and low side pressure and temperature sensors.

All of this sophistication is in an effort to squeeze that last
hundredth of an MPG CAFE rating.

The car's computer (known as the PCM or powertrain control module) can
take measurements and compare them to built in models to determine if
the CE light should be lit.  The dealer's diagnostic console can set
up standard conditions and do more rigorous testing.  You can't do
that as a user.  

In the old days, I'd fully load the system by either opening the doors
in the summer or putting a couple of 240 volt heaters in the front
seat in winter and then look at the evaporator superheat to begin with
my testing.  The back pressure regulating valves spoiled that method.

Another method that I use that I've never seen used anywhere else is
to don a mechanic's sthethescope and then press the probe HARD against
the expansion device.  Stressing the diaphragm acts as a high pass
filter and eliminates most of the engine and compressor sounds.

I can then listen to the flow of the refrigerant through the expansion
device.  With plenty of refrigerant, it sounds like water flowing in a
pipe.  With a large lack of refrigerant, only the sound of gas flowing
will be heard.  If the charge is intermittent and/or on some vehicle
system designs, a mixture of fluid and gas bubbles can be heard.

One has to carefully mix gauge readings, expansion device sounds,
temperatures and experience to figure out the system status.

One technique I use is to charge about an ounce of refrigerant and
listen to the change in sound of the expansion device.  If it doesn't
change and the sound is that of a mixture of bubbles and fluid and
everything else seems normal, I usually conclude that the system was
designed to operate in starved mode.

The most difficult to diagnose is a worn but not failed compressor.
I'm not a "parts changer" so I try to diagnose the compressor by
varying the load (heaters in the cabin) and comparing the pressures
and temperatures to the compressor OEM's charts.

Given the declining quality of high school grads that make up most
HVAC shop employees, few shops attempt much in the way of diagnosis.
They'll evacuate the system (for which you're charged an environmental
recovery fee while the company sells the used refrigerant for
recycling), change the expansion device and the filter/dryer and
recharge the system.  If that doesn't fix the problem, out comes the
refrigerant again (another fee) and the compressor gets changed.  If
that doesn't fix the system, the tech punts to the shop owner who
usually does have a clue.

Some enterprising techs will actually check the condenser to see if it
is dirty and needs cleaning.

So the AC system in a modern car is pretty much like everything else
on the vehicle - if you're not a dealer or have a $4-10k aftermarket
diagnostic system (plus $1000/year updates), you just can't do much.

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com 
Tellico Plains, Occupied TN
See website for email address

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#454499

Den lørdag den 1. april 2017 kl. 00.08.19 UTC+2 skrev Neon John:
> On Thu, 30 Mar 2017 14:31:35 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
> 
> As an engineer who has operated an industrial/commercial refrigeration
> business on the side for most of his career,  I'll take a shot.
> 
> >What can I learn (in absolute and relative terms) from monitoring
> >the temperature and pressure in high and low side coolant lines
> >to the ACbrr's evaporator coil?
> 
> I have no idea what "ACbrrr" is but I'll guess that you're speaking of
> the HVAC on a modern car.

I believe Don is talking about HVAC for a house   

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#454503

On 3/31/2017 3:33 PM, Lasse Langwadt Christensen wrote:
> Den lørdag den 1. april 2017 kl. 00.08.19 UTC+2 skrev Neon John:
>> On Thu, 30 Mar 2017 14:31:35 -0700, Don Y
>> <blockedofcourse@foo.invalid> wrote:
>>
>> As an engineer who has operated an industrial/commercial refrigeration
>> business on the side for most of his career,  I'll take a shot.
>>
>>> What can I learn (in absolute and relative terms) from monitoring
>>> the temperature and pressure in high and low side coolant lines
>>> to the ACbrr's evaporator coil?
>>
>> I have no idea what "ACbrrr" is but I'll guess that you're speaking of
>> the HVAC on a modern car.
>
> I believe Don is talking about HVAC for a house

Exactly.  There are heating related issues, as well -- but I think
I've got them covered (i.e., if intake temperature and output temperature
are the same, you're not getting any heat!  Is blower turning?  Is the
blower *motor* consuming power?  Is natural gas flowing?  etc.)

Here, what tends to happen is folks turn on their ACbrrr in preparation for
the cooling season (which typically begins in April; February, *this* year)
and "discover" that it doesn't work.  That discovery usually comes in the
form of "its not cooling"; rarely in terms of "the compressor isn't running".

It would be nice to be able to give some advance warning as to when and
whether PM is required (few folks have their ACbrrr "serviced" each year as
it is usually not needed -- just clean the condenser coils and make sure
the air filters in the blower have been changed, recently).

Knowing when the compressor is starting to see extra wear (as a result of
bad refrigerant levels *or* just plain wear-and-tear) and likely to fail.
Or, when efficiency is falling (few people keep track of how *much*
their ACbrrr runs; even fewer can correlate this with environmental
factors that would possibly account for the increased use) as a result
of a dirty evaporator coil or blocked vent; etc.

I.e., instead of an "open loop" PM practice, let the device assist the user
in *closing* that loop -- to save money (unnecessary service calls, reduced
energy efficiency) and increase comfort.

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#454527

On Fri, 31 Mar 2017 15:53:19 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

>On 3/31/2017 3:33 PM, Lasse Langwadt Christensen wrote:

>Here, what tends to happen is folks turn on their ACbrrr in preparation for

I assume that "ACbrrr" is some lame attempt at being cute.  Very well.

>the cooling season (which typically begins in April; February, *this* year)
>and "discover" that it doesn't work.  That discovery usually comes in the
>form of "its not cooling"; rarely in terms of "the compressor isn't running".

My experience has been that when a unit that worked fine last year
doesn't cool at all this year, it really is "the compressor isn't
running".  Usually caused by a failed run capacitor.  If caught soon
enough before the thermal cutout welds shut, a new capacitor fixes the
problem.  Given today's labor rates and the DRAMATIC increase in
efficiency that R401a has brought to the scene, burn-outs usually
aren't worth fixing so if the compressor is smoked, buy a new unit.

>
>It would be nice to be able to give some advance warning as to when and
>whether PM is required (few folks have their ACbrrr "serviced" each year as
>it is usually not needed -- just clean the condenser coils and make sure
>the air filters in the blower have been changed, recently).

So what inputs do you hope to use?  A fan motor with a worn bearing
does not draw more current until the rotor starts dragging and then
it's a repair emergency.  A worn out compressor draws the same current
(but not the same real power but few people have the capability to
measure true power in a low power factor environment.).  a low delta-T
across a coil if combined with a mass flow air detector can detect
diminished capacity but is it a dirty filter, a collapsed return duct
segment or ...

>
>Knowing when the compressor is starting to see extra wear (as a result of
>bad refrigerant levels *or* just plain wear-and-tear) and likely to fail.
>Or, when efficiency is falling (few people keep track of how *much*
>their ACbrrr runs; even fewer can correlate this with environmental
>factors that would possibly account for the increased use) as a result
>of a dirty evaporator coil or blocked vent; etc.

Quite expensive systems are available for commercial buildings that
can do that kind of stuff.  Question is, are you (or a customer if
you're thinking about commercializing your gadget) going to pay the
high cost?  Especially since the system has to be tuned to the
building and HVAC system.
>
>I.e., instead of an "open loop" PM practice, let the device assist the user
>in *closing* that loop -- to save money (unnecessary service calls, reduced
>energy efficiency) and increase comfort.

You save a LOT more money by simply having a modern >20SEER system
installed.  Hitachi has a hot-shit mini-split system that does 28SEER.
And with the R401a refrigerant, they'll continue to provide hot air
with it significantly below zero outside.

Mini-splits are designed for one per room.  The ultimate zone system.
Forget your silly monitoring of a 20th century system and use the
money to buy something modern.

If you think you're going to instrument a modern system then you face
exactly the same problem as with modern cars.  Computer controlled
everything.  Variable speed compressor and fans.  You can't know
whether a given set of measurements are indicating trouble or not
simply because you don't know what the computer is calling for.

John

John DeArmond
http://www.neon-john.com
http://www.tnduction.com 
Tellico Plains, Occupied TN
See website for email address

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#454537

On 3/31/2017 5:36 PM, Neon John wrote:
> On Fri, 31 Mar 2017 15:53:19 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
>
>> On 3/31/2017 3:33 PM, Lasse Langwadt Christensen wrote:
>
>> Here, what tends to happen is folks turn on their ACbrrr in preparation for
>
> I assume that "ACbrrr" is some lame attempt at being cute.  Very well.

I've used the reference numerous times before.  Others have managed to suss
its meaning.  Even *you* guessed its meaning -- just the wrong *application*.

>> the cooling season (which typically begins in April; February, *this* year)
>> and "discover" that it doesn't work.  That discovery usually comes in the
>> form of "its not cooling"; rarely in terms of "the compressor isn't running".
>
> My experience has been that when a unit that worked fine last year
> doesn't cool at all this year, it really is "the compressor isn't
> running".  Usually caused by a failed run capacitor.  If caught soon
> enough before the thermal cutout welds shut, a new capacitor fixes the
> problem.  Given today's labor rates and the DRAMATIC increase in
> efficiency that R401a has brought to the scene, burn-outs usually
> aren't worth fixing so if the compressor is smoked, buy a new unit.

If you can anticipate when it is likely to see a failure (e.g., poor
refrigerant levels) and suggest a service call before it becomes a
"significant expense", what value, that?

Our unit "failed to cool" many years ago.  Bad *fan* run capacitor.
Same thing happened to a neighbor's unit.  In each case, an (overpriced)
capacitor and 15 minutes of homeowner labor solved the problem without
necessitating a service call by a "professional".

Another neighbor had a "compressor fail" that was just a "breaker trip":
"Reset it and see if it trips again, any time soon" is a simple bit of
advice.

Yet another neighbor had "no cooling" -- only to discover that the
damper to the evaporative cooler had wedged itself open (and all the
refrigerated air was being exhausted out through the roof)

>> It would be nice to be able to give some advance warning as to when and
>> whether PM is required (few folks have their ACbrrr "serviced" each year as
>> it is usually not needed -- just clean the condenser coils and make sure
>> the air filters in the blower have been changed, recently).
>
> So what inputs do you hope to use?

Gee, I dunno.  Maybe I should POST A MESSAGE asking along those lines?  :>

> A fan motor with a worn bearing
> does not draw more current until the rotor starts dragging and then
> it's a repair emergency.  A worn out compressor draws the same current
> (but not the same real power but few people have the capability to
> measure true power in a low power factor environment.).  a low delta-T
> across a coil if combined with a mass flow air detector can detect
> diminished capacity but is it a dirty filter, a collapsed return duct
> segment or ...

It's *probably* more likely that its a dirty filter.  Regardless,
its easier for a user to CHECK a filter and, if that proves NOT to be
the problem, decide how much more effort he is willing to invest
before resorting to a service call.

IME, many folks are willing/eager to do their own service/maintenance.
However, they lack:
- the tools/ability to diagnose the problem
- knowledge of the system to identify the POSSIBLE causes
- the analytical reasoning to evaluate likelihoods of those causes
   (if your ACbrr doesn't cool, chances are that it is NOT because
   someone stole the compressor out of it!  OTOH, it *could* be that
   someone has stolen the copper lines feeding to/from it!)
- knowledge of the procedure to implement the repair
- ability to evaluate the success/effectiveness of their repair

Its a fortunate coincidence that machines are good at most of
this stuff:  instrumentation, measurement algorithms, expert systems,
etc.  The thing that they have trouble with is "unfastening screws"
and similar mechanical actions -- things that a willing human can
usually do with ease!  Esp if instructed with text and graphics/video!

Extend the AI so that it can share results with similar AI's and
"common problems with Model 123" can be merged into their rule
systems so the likelier remedies are more frequently pursued.

Learn.

>> Knowing when the compressor is starting to see extra wear (as a result of
>> bad refrigerant levels *or* just plain wear-and-tear) and likely to fail.
>> Or, when efficiency is falling (few people keep track of how *much*
>> their ACbrrr runs; even fewer can correlate this with environmental
>> factors that would possibly account for the increased use) as a result
>> of a dirty evaporator coil or blocked vent; etc.
>
> Quite expensive systems are available for commercial buildings that
> can do that kind of stuff.  Question is, are you (or a customer if
> you're thinking about commercializing your gadget) going to pay the
> high cost?  Especially since the system has to be tuned to the
> building and HVAC system.

We're not talking about making ice overnight to reduce cooling costs
during the day.  Or, hiring a staff to maintain the equipment in "top"
performance.  Engineering is all about cost-benefit analysis of
DIFFERENT solutions.

A manufacturer can print a "troubleshooting" page in the manual
for your HVAC system for damn little cost (pennies?  micropennies?)
But, for most USERS, there is damn little BENEFIT (they don't even
remember where the manual is stored, let alone recollect how complex the
troubleshooting may -- OR MAY NOT -- be).

OTOH, put it in front of his face, *for* him -- along with "your"
deductions of the likely problem based on "your" observations of
the system now -- and over the past several years -- and its value
increases dramatically.

>> I.e., instead of an "open loop" PM practice, let the device assist the user
>> in *closing* that loop -- to save money (unnecessary service calls, reduced
>> energy efficiency) and increase comfort.
>
> You save a LOT more money by simply having a modern >20SEER system
> installed.  Hitachi has a hot-shit mini-split system that does 28SEER.
> And with the R401a refrigerant, they'll continue to provide hot air
> with it significantly below zero outside.

So, all the existing systems should be scrapped and replaced, immediately!
And, all cars that weren't manufactured in 2017 should similarly be scrapped.
And, pickup trucks.  And...

You're not acknowledging the realities that all those existing owners face.

"If I had a money tree out back, I'd..."

There are homes here that don't have ductwork.  There are (expensive!)
homes that have ductwork retrofitted to the EXTERIOR of the building
(i.e., sitting out in the sun).  There are folks who can't afford
refrigeration -- which confounds the city as it tries to curtail
*water* use (evaporative coolers use a LOT of water!)

I'm sure all of these folks would LOVE to have your 28 SEER systems
installed.  How do you suggest they purchase them?  And, install
them?

> Mini-splits are designed for one per room.  The ultimate zone system.
> Forget your silly monitoring of a 20th century system and use the
> money to buy something modern.
>
> If you think you're going to instrument a modern system then you face
> exactly the same problem as with modern cars.  Computer controlled
> everything.  Variable speed compressor and fans.  You can't know
> whether a given set of measurements are indicating trouble or not
> simply because you don't know what the computer is calling for.

Gee, so obviously the idea of instrumenting an HVAC system has occurred to
someone!  It's so reassuring to know I'm on the right track!  ;)

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#454621

On Fri, 31 Mar 2017 19:22:40 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

>On 3/31/2017 5:36 PM, Neon John wrote:
>> On Fri, 31 Mar 2017 15:53:19 -0700, Don Y
>> <blockedofcourse@foo.invalid> wrote:

>> So what inputs do you hope to use?
>
>Gee, I dunno.  Maybe I should POST A MESSAGE asking along those lines?  :>

But your question is like asking "how can I instrument a car engine to
predict failure?".  There is no general purpose set of parameters that
apply to all types of systems.

To correct a mistake I made in the previous post, I went dyslexic with
the refrigerant name.  It should be R-410a instead of R-401a.

>It's *probably* more likely that its a dirty filter.  Regardless,
>its easier for a user to CHECK a filter and, if that proves NOT to be
>the problem, decide how much more effort he is willing to invest
>before resorting to a service call.

Thumbing through my Johnstone Supply catalog, I see that thermostats
with a "filter" idiot light are available so presumably this feature
is being offered.  I quit doing air conditioning many years ago and
only do refrigeration now so I'm not up on the finer details of
things.

>
>IME, many folks are willing/eager to do their own service/maintenance.
>However, they lack:

>- the tools/ability to diagnose the problem
>- knowledge of the system to identify the POSSIBLE causes
>- the analytical reasoning to evaluate likelihoods of those causes
>   (if your ACbrr doesn't cool, chances are that it is NOT because
>   someone stole the compressor out of it!  OTOH, it *could* be that
>   someone has stolen the copper lines feeding to/from it!)
>- knowledge of the procedure to implement the repair
>- ability to evaluate the success/effectiveness of their repair

And most importantly, they lack the licenses needed to purchase
refrigeration nowadays.

>Extend the AI so that it can share results with similar AI's and
>"common problems with Model 123" can be merged into their rule
>systems so the likelier remedies are more frequently pursued.

Do you have any idea the number of brands, models and variations there
are on the market?  Probably numbers in the thousands.  Add in the
installer-induced variations in split units and the number of sets of
data become enormous.



>> You save a LOT more money by simply having a modern >20SEER system
>> installed.  Hitachi has a hot-shit mini-split system that does 28SEER.
>> And with the R401a refrigerant, they'll continue to provide hot air
>> with it significantly below zero outside.
>
>So, all the existing systems should be scrapped and replaced, immediately!
>And, all cars that weren't manufactured in 2017 should similarly be scrapped.
>And, pickup trucks.  And...

Stop putting words in my mouth.  A smart owner (or his consultant)
should do a financial analysis on the system, taking into account the
age of the system, the amount of energy it uses, energy cost,
probability of failure and the resultant repair costs (all the major
brand names are now offering 10 year warranties so repair cost drops
out of the new unit column) vs the cost of simply replacing the unit
vs scrapping the whole works and going mini-split.

>There are homes here that don't have ductwork.  There are (expensive!)
>homes that have ductwork retrofitted to the EXTERIOR of the building
>(i.e., sitting out in the sun).  There are folks who can't afford
>refrigeration -- which confounds the city as it tries to curtail
>*water* use (evaporative coolers use a LOT of water!)
>
>I'm sure all of these folks would LOVE to have your 28 SEER systems
>installed.  How do you suggest they purchase them?  And, install
>them?

Modification to the structure involves pruning a branch circuit to the
location and drilling one single 1" diameter hole through the wall.

A 14kBTU unit (great room or average den/kitchen) condensing unit is
about the size of an old fashioned hard suitcase.  The evaporator is
normally a rectangular unit that hangs on the wall.  However,
evaporators can be had that are disguised to look like picture frames
and ones that hang from the ceiling.  The condensing unit can easily
be hidden behind shrubby and after initial cool-down is so quiet as to
be practically un-noticeable.

Buying a unit is as simple as googling "mini-split heat pumps"
(optionally adding a brand name) and selecting an on-line vendor.

A crafty homeowner can do the installation with ordinary hand tools
right up to charging the system with refrigerant.  A special R-410a
license is needed to buy and work with the stuff because it is a very
high pressure refrigerant.  Evaporator pressure at 70 deg is 201 psi.
Condensing pressure on a hot summer day may be as high as 600 psi.  I
have the license but I don't like working with the stuff even though
the gauges, manifold and hoses are much more rugged than for more
common refrigerants.

There is a place in Brasstown Bald, NC called the Cambell School for
the arts and crafts (or something like that) that is situated on a
large 19th century farm.  Many of the buildings are made of stacked
and cemented river rock.  Mini-splits have been installed in all the
buildings.  They had someone paint the condensing units and the single
line that goes indoors to match the surroundings.  I would have never
known they were there had I not see an air handling unit hanging on
the inside wall of one of the buildings.

So in summary, if you can drill a 1" hole through an outside wall, you
can install mini-splits.

Mini-splits are so refined because they are what most of the rest of
the world uses where energy is expensive and incomes are low.  Look at
a photo or video of most any foreign high rise and you'll see little
mini-split hanging all over the buildings like ticks on a dog.

>Gee, so obviously the idea of instrumenting an HVAC system has occurred to
>someone!  It's so reassuring to know I'm on the right track!  ;)

25 cents/kWH for electricity, what my partner in San Diego pays after
the first 1000 kWh spurs many such optimizations.

John

John DeArmond
http://www.neon-john.com
http://www.tnduction.com 
Tellico Plains, Occupied TN
See website for email address

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#454640

On 4/1/2017 9:18 AM, Neon John wrote:
> On Fri, 31 Mar 2017 19:22:40 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
>
>> On 3/31/2017 5:36 PM, Neon John wrote:
>>> On Fri, 31 Mar 2017 15:53:19 -0700, Don Y
>>> <blockedofcourse@foo.invalid> wrote:
>
>>> So what inputs do you hope to use?
>>
>> Gee, I dunno.  Maybe I should POST A MESSAGE asking along those lines?  :>
>
> But your question is like asking "how can I instrument a car engine to
> predict failure?".  There is no general purpose set of parameters that
> apply to all types of systems.

I can spend years becoming expert in the technology -- only to watch it
continually evolve.

Or, I can look for ideas towards an "80-20" solution and make PROVISIONS
to address them.

Clearly, oil fired hot water heat differs from gas forced air.  And, both
differ from a pellet stove.  Just as an evaporative cooler differs from
an ACbrrr which differs from a natural gas fired cooling.

I.e., there are obviously different approaches to the problem and different
application domains.

But, that doesn't invalidate the concept of instrumenting those plants
and installing local expert systems to advise the "users" of recommended
PM as well as anticipatory and reactionary diagnostics.

Doing it in an existing "dumb" installation is costly -- because there are no
mechanisms by which the kit can talk to the user.  The interface is just
a set of switches (heat/cool/fan/off) and settings (temperature).

*And*, because the kit can't talk to anything ELSE that could assist it
in determining the efficacy of its operation.  It doesn't know how hot/cold
it is, outside.  Or, if the wind is blowing.  Or, if it is humid.  Or, even
if the *sun* is up!

It can't talk to other such units -- directly or indirectly via a shared
(remote) knowledge base:   "Gee, this model ACbrrr seems to exhibit the
following failure mode(s) in these usage conditions..."

Build more efficient ACbrrrs that continue to be isolated ISLANDS and
the problem will persist.  The "thing" that will tie them together will
be the HVAC contractor showing up when YOURS shits the bed.  Because YOURS
won't be able to know what to look for in itself and its environs nor to
learn from the experiences of other similar/identical units.

> To correct a mistake I made in the previous post, I went dyslexic with
> the refrigerant name.  It should be R-410a instead of R-401a.
>
>> It's *probably* more likely that its a dirty filter.  Regardless,
>> its easier for a user to CHECK a filter and, if that proves NOT to be
>> the problem, decide how much more effort he is willing to invest
>> before resorting to a service call.
>
> Thumbing through my Johnstone Supply catalog, I see that thermostats
> with a "filter" idiot light are available so presumably this feature
> is being offered.  I quit doing air conditioning many years ago and
> only do refrigeration now so I'm not up on the finer details of
> things.

I'd wager the light comes on after a fixed number of "blower hours".
It knows nothing of the quality of filter installed, the amount of
dirt/dust in the edifice, the pressure drop across its surface, etc.

Like changing the oil in your car after a fixed number of miles
driven -- or elapsed days.  And, ASSUMING that all cars lead
similar lives.

Given that there are at least two CPUs in most HVAC systems
(one in the furnace, another in the thermostat) it seems silly for
them to just twiddle their thumbs replacing a comparator and set
of hardwired logic!

>> IME, many folks are willing/eager to do their own service/maintenance.
>> However, they lack:
>
>> - the tools/ability to diagnose the problem
>> - knowledge of the system to identify the POSSIBLE causes
>> - the analytical reasoning to evaluate likelihoods of those causes
>>   (if your ACbrr doesn't cool, chances are that it is NOT because
>>   someone stole the compressor out of it!  OTOH, it *could* be that
>>   someone has stolen the copper lines feeding to/from it!)
>> - knowledge of the procedure to implement the repair
>> - ability to evaluate the success/effectiveness of their repair
>
> And most importantly, they lack the licenses needed to purchase
> refrigeration nowadays.

If your system needs recharging and/or evacuation, you have to
call a "professional".  But, that doesn't stop you from doing other
PM.  Or, from the system itself determining when more extensive
maintenance is called for -- before becoming "urgent".

>> Extend the AI so that it can share results with similar AI's and
>> "common problems with Model 123" can be merged into their rule
>> systems so the likelier remedies are more frequently pursued.
>
> Do you have any idea the number of brands, models and variations there
> are on the market?  Probably numbers in the thousands.  Add in the
> installer-induced variations in split units and the number of sets of
> data become enormous.

Do you have any idea the number of brands, models and variations there
are on the market of cars?  coffee pots?  personal computers?  cell
phones?  televisions?  Does any of that prevent owners of those
bits of kit from sharing their failure/repair experiences?  Does
it prevent those devices THEMSELVES from sharing their experiences
without requiring the owner/repairman to take explicit actions?

Do you think your car doesn't "tattle" on what its noticed about
its performance and your driving patterns when it visits the dealer?
Do you think the dealer -- and manufacturer -- DISCARD that information?

Why can't other INTERNETWORKED devices similarly share information?
Why does connectedness just mean "able to be controlled remotely"?

>>> You save a LOT more money by simply having a modern >20SEER system
>>> installed.  Hitachi has a hot-shit mini-split system that does 28SEER.
>>> And with the R401a refrigerant, they'll continue to provide hot air
>>> with it significantly below zero outside.
>>
>> So, all the existing systems should be scrapped and replaced, immediately!
>> And, all cars that weren't manufactured in 2017 should similarly be scrapped.
>> And, pickup trucks.  And...
>
> Stop putting words in my mouth.  A smart owner (or his consultant)
> should do a financial analysis on the system, taking into account the
> age of the system, the amount of energy it uses, energy cost,
> probability of failure and the resultant repair costs (all the major
> brand names are now offering 10 year warranties so repair cost drops
> out of the new unit column) vs the cost of simply replacing the unit
> vs scrapping the whole works and going mini-split.

Exactly *zero* of the ~200 homes in this subdivision have deviated from
the "single, central compressor" cooling system (I walk the neighborhood
daily).  One of the businesses that I visit has installed them (small
compressor/condenser on the rooftop; evaporator an eyesore on the wall
in each office space.

By contrast, perhaps 20% now have roof-mounted photovoltaics.  And,
probably 25% of the homes with pools have passive solar (pool) water
heating.

IME (for reasons outlined previously), folks don't "replace" HVAC systems
until they start exhibiting problems -- most typically refrigeration.
Two neighbors have (air sourced) heat pumps for heating/cooling.  Surely
they'd have considered it worthwhile to pay for gas to be run to their
homes -- especially when the gas lines were replaced two years ago and
the crews on-site!

>> There are homes here that don't have ductwork.  There are (expensive!)
>> homes that have ductwork retrofitted to the EXTERIOR of the building
>> (i.e., sitting out in the sun).  There are folks who can't afford
>> refrigeration -- which confounds the city as it tries to curtail
>> *water* use (evaporative coolers use a LOT of water!)
>>
>> I'm sure all of these folks would LOVE to have your 28 SEER systems
>> installed.  How do you suggest they purchase them?  And, install
>> them?
>
> Modification to the structure involves pruning a branch circuit to the
> location and drilling one single 1" diameter hole through the wall.

What do you do when you have no basement nor attic through which to run
that branch circuit?  Or, when you have to add a sub-panel to accommodate
the extra circuits (fed by the "old" compressor circuit)?  And, the walls
are concrete/slump block.

> A 14kBTU unit (great room or average den/kitchen) condensing unit is
> about the size of an old fashioned hard suitcase.  The evaporator is
> normally a rectangular unit that hangs on the wall.  However,
> evaporators can be had that are disguised to look like picture frames
> and ones that hang from the ceiling.  The condensing unit can easily
> be hidden behind shrubby and after initial cool-down is so quiet as to
> be practically un-noticeable.

Shrubbery?  We live in the *desert*.  You want me to have one of these for
the living room (maybe it can bleed over into the dining room, as well).
Another for the kitchen and family rooms.  Something else to address the
bedrooms (in concert?) -- and hope the spillover handles the other
common spaces.  And, no one will notice these changes to the interior
or exterior of the house?

> Buying a unit is as simple as googling "mini-split heat pumps"
> (optionally adding a brand name) and selecting an on-line vendor.
>
> A crafty homeowner can do the installation with ordinary hand tools
> right up to charging the system with refrigerant.  A special R-410a
> license is needed to buy and work with the stuff because it is a very
> high pressure refrigerant.  Evaporator pressure at 70 deg is 201 psi.
> Condensing pressure on a hot summer day may be as high as 600 psi.  I
> have the license but I don't like working with the stuff even though
> the gauges, manifold and hoses are much more rugged than for more
> common refrigerants.
>
> There is a place in Brasstown Bald, NC called the Cambell School for
> the arts and crafts (or something like that) that is situated on a
> large 19th century farm.  Many of the buildings are made of stacked
> and cemented river rock.  Mini-splits have been installed in all the
> buildings.  They had someone paint the condensing units and the single
> line that goes indoors to match the surroundings.  I would have never
> known they were there had I not see an air handling unit hanging on
> the inside wall of one of the buildings.

And, who *paid* for all this?

Our next home will be below grade -- because it is just silly NOT to
exploit the insulating capabilities of earth (regardless of whether
you live in a cold or warm climate).  Far more effective use of
construction dollars than putzing around with insulation in walls,
ceilings, floors, triple glazed windows, etc.

But, you don't get from "existing structure" to "below grade" structure
just by spending money, /in situ/.  It's just *too* expensive to raze
a building and erect another in its place.

When you build "new", you can make allowances for where you want to
site the compressor, evaporator, furnace, utilities, etc.  When you
"start from existing", your choices are usually a lot more expensive
and constrained.

E.g., many homes have added water softeners/filtration systems, here
(our water is very hard and is continually degrading in quality as
demand outpaces growth of supply).  But, all water mains enter homes
through the front yard after passing through a meter at curbside.
Once at the home, the line immediately dives into the slab and feeds
the fixtures throughout the house.

So, adding anything upstream of the house requires it be sited in
the front yard -- at whatever place the supply *happens* to connect
to your home!  *Or*, intercepting the main as it enters the property
and routing it to some other place where the equipment can be installed
(i.e., outdoors!); then returning the treated water to the point of
interception to enter the house properly.  I.e., you can easily spend
$2000+ on the *installation* of a water softener -- trenching around the
perimeter of the house, burying the 100 feet of 3/4 - 1" pipe, tying it
in to the severed main and inlet, etc.

Then, worrying about how you were going to protect the equipment
from the weather, packrats, etc.  *And*, where you'd be storing all
the "salt" that would make servicing the brine tank convenient, yet
not require it to be stored outdoors, as well.

In other parts of the country, this would be cutting the supply line,
sweating a couple of fittings and setting the unit in place.  Then,
piling your salt supply near the brine tank.

So, folks buy bottled water (stupid!) instead of addressing THEIR
water supply.  That $2K (plus the cost of the kit itself) is a mighty
big hurdle for most to get past!

Similarly, our municipal water pressure is ~120psig.  Most water fittings
(dishwasher, washing machine, dryer, water softener, irrigation system,
evaporative cooler, toilet, etc.) are designed for a nominal 80psig
maximum.  Fixing this problem requires installing a pressure reducing valve
upstream of the municipal water supply inlet.  It's a small device -- about
the size of your palm -- unlike the behemoth water softeners.  So, its
conceivable that you could slip one in the supply line as it exits the
ground and passes into the exterior wall of the house (before diving into
the slab).

A PRV runs about $75.  And, as its relatively little labor to install
(i.e., no trenching around the house; just two joints to sweat), you
could probably get one installed for $200.  So, figure $300 out-of-pocket.

I doubt 10% of the older homes in the neighborhood have one (newer homes
do because of code changes -- the city *knows* the supply is operating
well above the expected maximum for most appliances/fixtures).

Of the homes that have PRV's, I've yet to find one that has the "required"
expansion tank on the load side!  Because finding a spot for a cubic foot tank
AND plumbing it starts to make it a more complicated/expensive endeavor.
So, even when installing a "PRV with bypass", the home is no better off
(worst case) than they were, without the PRV!  The water in the NOW CLOSED
SYSTEM expands as the water heater makes up for consumption.  This quickly
raises the pressure in that closed system to well above the original
"high supply pressure" -- until the bypass vents it back into the municipal
supply.

And, these are relatively "low tech" sorts of upgrades.  But, people
don't see the cost *avoided* by implementing them vs. the cost incurred
*to* implement them.  Most folks don't even know what the muni water
pressure is nor what it *should* be!  Do *you* have a pressure gauge
on your water inlet?  (Of course *I* do!  As well as downstream from the
PRV -- to assure myself that it is, in fact, working!)

> So in summary, if you can drill a 1" hole through an outside wall, you
> can install mini-splits.
>
> Mini-splits are so refined because they are what most of the rest of
> the world uses where energy is expensive and incomes are low.  Look at
> a photo or video of most any foreign high rise and you'll see little
> mini-split hanging all over the buildings like ticks on a dog.
>
>> Gee, so obviously the idea of instrumenting an HVAC system has occurred to
>> someone!  It's so reassuring to know I'm on the right track!  ;)
>
> 25 cents/kWH for electricity, what my partner in San Diego pays after
> the first 1000 kWh spurs many such optimizations.

I think we're paying about half that.  We'd save more by discarding the
freeezer (sitting out in the garage), unplugging the various wall-wart
powered devices scattered around the house (even at < 1W/each, having
dozens of them adds up!) and forcing the computers to "sleep" more
aggressively (there are 4 computers running, currently; two actively in
use, another servicing my network, and a fourth waiting for me to finish
this post so I can get back to "work").

But money is only part of the equation.  There's also comfort/convenience
(its no fun to lose cooling/heating when you NEED it -- and, you only know
that it is gone BECAUSE you need it!).  And, there is the "independence"
factor:  being able to continue to live in your own home (vs. a retirement
home or assisted care facility) without having to keep a lengthy list of
all the "things" you should be checking on -- or hiring someone to check
on FOR you.

Do you regularly visit your folks (or kids!) to ensure the house is "intact"
to address their anticipated needs for the next month (or five)?  Do
*they* remember to change the filter in their furnace?  Or, have the
compressor serviced?   Check the evaporative cooler for leaks?  etc.
It's April -- time for me to make my annual survey of the condition of
the roof (so I can affect repairs before it gets too hot *or* Monsoon
starts)...

Wouldn't it be nice if those things could remind them of these needs?
Or, *you*, on their behalf?  Instead of warehousing them in a $3-4K/month
"facility" that relieves them of those concerns?

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#454771

On Sat, 1 Apr 2017 11:17:12 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

Don, I think that at this point you're just arguing to be arguing.

>But, that doesn't invalidate the concept of instrumenting those plants
>and installing local expert systems to advise the "users" of recommended
>PM as well as anticipatory and reactionary diagnostics.
>
>Doing it in an existing "dumb" installation is costly -- because there are no
>mechanisms by which the kit can talk to the user.  The interface is just
>a set of switches (heat/cool/fan/off) and settings (temperature).
>
>*And*, because the kit can't talk to anything ELSE that could assist it
>in determining the efficacy of its operation.  It doesn't know how hot/cold
>it is, outside.  Or, if the wind is blowing.  Or, if it is humid.  Or, even
>if the *sun* is up!

So can we agree that predictive failure instrumentation on "dumb"
units is impossible?

>
>It can't talk to other such units -- directly or indirectly via a shared
>(remote) knowledge base:   "Gee, this model ACbrrr seems to exhibit the
>following failure mode(s) in these usage conditions..."
>
>Build more efficient ACbrrrs that continue to be isolated ISLANDS and
>the problem will persist.  The "thing" that will tie them together will
>be the HVAC contractor showing up when YOURS shits the bed.  Because YOURS
>won't be able to know what to look for in itself and its environs nor to
>learn from the experiences of other similar/identical units.

The major manufacturers are doing just that.  There's nothing really
to be gained from communicating a potential failure to the user.  The
only thing he could do with that information is call the service tech.
A "call for service" light (in addition to the filter light), the
equivalent of a "check engine" light on the thermostat is all that is
necessary.

The tech will come out at no cost to the owner because of the 10 year
warranty, plug in his diagnostic set and see what "code" caused the
service light.  Exactly like it's done in the automotive world.

This is happening *NOW*.  The problem is that there is no EPA
regulation requiring standardization of the trouble codes as there is
in the automotive world.  That means that every brand's diagnostics
are proprietary and that they won't be released unless forced to.

The independent service tech is an endangered species because of the
10 year warranties and because of the proprietary nature of the
systems.  There will be some bottom feeders (Rheem and Ruud for
example) around for a few more years for use in cheap spec houses but
they'll be pushed out by more and more stringent SEER regulations.


>I'd wager the light comes on after a fixed number of "blower hours".
>It knows nothing of the quality of filter installed, the amount of
>dirt/dust in the edifice, the pressure drop across its surface, etc.

You would lose that wager in most cases.


>Do you have any idea the number of brands, models and variations there
>are on the market of cars?  coffee pots?  personal computers?  cell
>phones?  televisions?  Does any of that prevent owners of those
>bits of kit from sharing their failure/repair experiences?  Does
>it prevent those devices THEMSELVES from sharing their experiences
>without requiring the owner/repairman to take explicit actions?

with the exception of cars (where the diagnostics are standardized by
law), none of the other items are repaired anymore except maybe by a
few nerds.   I mean, would you really waist your time repairing a $15
coffee pot?

>
>Do you think your car doesn't "tattle" on what its noticed about
>its performance and your driving patterns when it visits the dealer?
>Do you think the dealer -- and manufacturer -- DISCARD that information?

Well, I helped design the http://www.megasquirt.com aftermarket EFI,
used to run a tuner shop on the side, published a magazine called
Performance Engineering that dealt primarily automotive high tech,
used to hack GM PCMs for use on other engines (there is a very private
mailing list where fellow EFI hackers share their exploits), own a
very sophisticated OBD-II gateway and the software that goes with it
so yes, I have a clue as to what data is exchanged via the OBD-II bus
at the dealership or independent garage.

BTW, if you have any real interest in this area, I strongly recommend
the TriCAN gateway from this guy

http://www.obd-2.com/

The software is free and will give you a real education on the state
of government-mandated standardization.  The powertrain codes (the
1000 series) has been standardized by statute but none of the rest of
the stuff that travels on the bus has been.  Things like ABS,
stability control, cabin environmental control and even thing such as
tail light modules chat on the CAN bus.  The manufacturers will
release some of these so-called "extended" coded for a price.  GM's
was $700 last time I checked.

George Peper, the guy behind obd-2.com, pays for the all the extended
code sets and incorporates them into his free software.  He's probably
the world's foremost expert on multi-brand OBD-II technology.
>
>Why can't other INTERNETWORKED devices similarly share information?
>Why does connectedness just mean "able to be controlled remotely"?

Because it makes no economic sense to do so.  The major manufacturers'
diagnostic systems collect diagnostic data and sends it back to the
manufacture when the tech connects to the net.  In other words, what
you're proposing is already happening.


>Exactly *zero* of the ~200 homes in this subdivision have deviated from
>the "single, central compressor" cooling system (I walk the neighborhood
>daily).  One of the businesses that I visit has installed them (small
>compressor/condenser on the rooftop; evaporator an eyesore on the wall
>in each office space.
>
>By contrast, perhaps 20% now have roof-mounted photovoltaics.  And,
>probably 25% of the homes with pools have passive solar (pool) water
>heating.

The government pays huge subsidies for solar installations.  Not so
for more efficient HVAC.  The result is evident in your neighborhood.
If the government ever offered HVAC upgrade subsidies (as a fiscal
conservative I hope they never do), you'd see the same thing happen as
with solar.
>

>What do you do when you have no basement nor attic through which to run
>that branch circuit?  Or, when you have to add a sub-panel to accommodate
>the extra circuits (fed by the "old" compressor circuit)?  And, the walls
>are concrete/slump block.

I'd do the same thing that they did over at the Cambell School.  Bury
NM cable around the outside perimeter of the building.

Bitching about maybe having to use a subpanel is a bit trite, wouldn't
you agree?


>Shrubbery?  We live in the *desert*.  You want me to have one of these for
>the living room (maybe it can bleed over into the dining room, as well).
>Another for the kitchen and family rooms.  Something else to address the
>bedrooms (in concert?) -- and hope the spillover handles the other
>common spaces.  And, no one will notice these changes to the interior
>or exterior of the house?

Believe it or not, the entire world isn't like where you live.

Maybe a swamp cooler does you better.  I claim no knowledge of
environments other than the Southeast.

>> There is a place in Brasstown Bald, NC called the Cambell School for
>> the arts and crafts (or something like that) that is situated on a
>> large 19th century farm.  Many of the buildings are made of stacked
>> and cemented river rock.  Mini-splits have been installed in all the
>> buildings.  They had someone paint the condensing units and the single
>> line that goes indoors to match the surroundings.  I would have never
>> known they were there had I not see an air handling unit hanging on
>> the inside wall of one of the buildings.
>
>And, who *paid* for all this?

Do you have a point to make?  Of course the school paid for it.  It
was a choice of either no environmental controls in a part of the
country that goes below 0 in the winter and is swelteringly hot and
humid in the summer and having a very efficient and non-obtrusive
system that makes the building habitable.  That should be obvious to
you.

>
>Our next home will be below grade -- because it is just silly NOT to

Good for you.  Mine was going to be too until time slipped away and I
got too old to make it happen.  I own the perfect property.  60 acres
of forested land with a spring fed 5 acre lake.  A nice slope on one
side where the underground house could have been build and enough flow
from the springs to use micro-hydro generation to be off-grid.  And,
of course, the lake to use for the water-sourced heat pump(s).

<much irreverent to the thread stuff deleted>



>I think we're paying about half that.  We'd save more by discarding the
>freeezer (sitting out in the garage), unplugging the various wall-wart
>powered devices scattered around the house (even at < 1W/each, having
>dozens of them adds up!) and forcing the computers to "sleep" more
>aggressively (there are 4 computers running, currently; two actively in
>use, another servicing my network, and a fourth waiting for me to finish
>this post so I can get back to "work").

I pay 12 cents/kWh so such petite optimizations aren't worth my
effort.  Changing out my (maybe) 10 SEER central unit with leaky duct
work with mini-splits is.  I'm currently buying kits as spare change
allows and storing them in the basement.  Probably do the conversion
next year.  Payback will be about 4 years.  My contractor discount is
50% so I pay half what you would pay from one of the internet vendors.

>
>But money is only part of the equation.  There's also comfort/convenience
>(its no fun to lose cooling/heating when you NEED it -- and, you only know
>that it is gone BECAUSE you need it!).  And, there is the "independence"
>factor:  being able to continue to live in your own home (vs. a retirement
>home or assisted care facility) without having to keep a lengthy list of
>all the "things" you should be checking on -- or hiring someone to check
>on FOR you.

You just made the case for multiple mini-split systems that provide
multiple redundancy and have no single point of failure.

>
>Do you regularly visit your folks (or kids!) to ensure the house is "intact"
>to address their anticipated needs for the next month (or five)?  Do
>*they* remember to change the filter in their furnace?  Or, have the
>compressor serviced?   Check the evaporative cooler for leaks?  etc.
>It's April -- time for me to make my annual survey of the condition of
>the roof (so I can affect repairs before it gets too hot *or* Monsoon
>starts)...

I would if I still had any of those people.  

>
>Wouldn't it be nice if those things could remind them of these needs?

Why, when an entry in the calendar of their cellphone to have the
system serviced would do the same thing?

OK, I'm finished with this thread.  I hope other readers have gleaned
some helpful info.  

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com 
Tellico Plains, Occupied TN
See website for email address

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#454806

On 4/2/2017 9:26 AM, Neon John wrote:
> On Sat, 1 Apr 2017 11:17:12 -0700, Don Y <blockedofcourse@foo.invalid>
> wrote:
>
> Don, I think that at this point you're just arguing to be arguing.

I'm arguing for something in which I believe.  Namely, that real-time
monitoring of <things> produces useful information BEFORE that
information would otherwise be "collected" (e.g., by a service call).

An admittedly dated paper
<http://aceee.org/files/proceedings/2002/data/papers/SS02_Panel1_Paper05.pdf>
    "Conclusions
     + Contractors are willing to put forth the effort necessary to
       make sure air conditioning systems are operating within manufacturers’
       refrigerant charge specifications, once they are taught to do it
       correctly and are held to an easy means of checking their work.
[Note that contractors only got *involved* when the user CALLED for service]
     + 65% of the residential systems tested required repairs.
     + 71% of the light commercial systems tested required repairs.
     + 57% of the systems were outside specification for refrigerant level.
     + Above 76 degrees outdoor temperature, residential humidity ratios
       average above 0.01 lbs. per lb. of dry air.
     + The current temperature split method of identifying units with low
       airflow is flawed and should be revised to eliminate biases associated
       with the conditions at the time the measurements are made

Elsewhere (same reference):
    "Field surveys indicate if charge and airflow were corrected within
    achievable limits in residential AC systems, seasonal efficiencies
    would increase an average of 16%.  Effects on peak efficiency are
    also significant. Previous studies have found newly installed air
    conditioning systems also experience problems with refrigerant charge
    and airflow. Even units that are installed correctly develop charge and
    airflow problems over time.
Note the systems described there only encounters data gathered by an on-site
technician (i.e., not real-time) -- so, the user had either NOTICED a
problem (and called for service) or called for PM and the contractor
stumbled onto the problem (by following the guidelines in the paper).

>> But, that doesn't invalidate the concept of instrumenting those plants
>> and installing local expert systems to advise the "users" of recommended
>> PM as well as anticipatory and reactionary diagnostics.
>>
>> Doing it in an existing "dumb" installation is costly -- because there are no
>> mechanisms by which the kit can talk to the user.  The interface is just
>> a set of switches (heat/cool/fan/off) and settings (temperature).
>>
>> *And*, because the kit can't talk to anything ELSE that could assist it
>> in determining the efficacy of its operation.  It doesn't know how hot/cold
>> it is, outside.  Or, if the wind is blowing.  Or, if it is humid.  Or, even
>> if the *sun* is up!
>
> So can we agree that predictive failure instrumentation on "dumb"
> units is impossible?

You can't say that.  Have you had your "dumb" unit instrumented, 24/7/365
and had anyone/anything WATCHING that data?  Or, collecting that data from
other identical models?  What other observations would a "smarter" device
need to improve its assessment of the health, efficiency and life expectancy
of itself?  What outside the extents of the ACbrrr itself can bear on
performance -- that the ACbrrr vendor doesn't consider practical to instrument?

Does his brand-fangled new unit know that the reason the system's
performance suffers in THIS room is because the exposed windows
let too much afternoon sun into the space?  Can it talk with it's
peer (split) in the ADJOINING ROOM to "compare notes":  "Gee, why
is your duty cycle so much different from mine?"   Or, advise the
homeowner of those differences and likely causes?  ("Check Engine:
code 123442989:  excessive performance differential vs. other
co-located units.  Call for service.")

*Do* they note that they've been "off" for the past week and can
they deduce that the homeowner may have switched on the swamp cooler,
instead, to address cooling needs?  And, the incredibly high indoor
humidity -- differing considerably from that measured outside the
home -- is due to the moisture deliberately introduced to the living
space?  Or, that the misguided homeowner has been attempting to use
both cooling technologies at nearly the same time (use swamp until
it can't keep up; then switch on the ACbrrr).

[There are people who *do* this -- because nothing has told them
that it is counterproductive]

Just how much can those "smart" devices say with that "check engine"
light (and the intervention of a technician at a service call)?  :>

>> It can't talk to other such units -- directly or indirectly via a shared
>> (remote) knowledge base:   "Gee, this model ACbrrr seems to exhibit the
>> following failure mode(s) in these usage conditions..."
>>
>> Build more efficient ACbrrrs that continue to be isolated ISLANDS and
>> the problem will persist.  The "thing" that will tie them together will
>> be the HVAC contractor showing up when YOURS shits the bed.  Because YOURS
>> won't be able to know what to look for in itself and its environs nor to
>> learn from the experiences of other similar/identical units.
>
> The major manufacturers are doing just that.  There's nothing really
> to be gained from communicating a potential failure to the user.  The
> only thing he could do with that information is call the service tech.
> A "call for service" light (in addition to the filter light), the
> equivalent of a "check engine" light on the thermostat is all that is
> necessary.

So, a service call to change a filter?  Or, clean the condenser coils?
Assume this *is* covered under warranty.  Makes you wonder how much
higher the sell price was to accommodate these EXPECTED future actions!

> The tech will come out at no cost to the owner because of the 10 year
> warranty, plug in his diagnostic set and see what "code" caused the
> service light.  Exactly like it's done in the automotive world.

... for folks with (new) units and 10 year warranties still in force.
You seem to think this covers a majority of the sites/users.

> This is happening *NOW*.

And companies make ice, *now*.  But, that doesn't mean it is happening
across the board.

You can't base your decisions on "ideal".  Instead, you have to deal
with "reality".  Unless *forced* to do so (because of legislative action
or an outright failure in their equipment), people tend not to
opt to replace things just because something better is available
(unlike disposable consumer kit).

We can produce about 6KW/m^2 per day, year round.  Damn near any
structure can host enough PV panels to power the contents of that
structure (assuming an available storage medium).  E.g., we could
EASILY produce a surplus of power from our modest home.  Why don't
we?  Why don't *most* of the homes around us do this (instead of
the ~20%)?

Because its easier to just keep paying a bit more each month and not
have to worry about selecting the kit and biting the bullet.  "If
it ain't broke, don't fix it!"  The same reason the furnace/ACbrrr/swamp
coolers in homes remain in place until *broken*, beyond repair
(yeah, the service tech will tell you that you're going to get a more
efficient NEW unit... but, you're still faced with ponying up $5K
for a unit for (this) modest home.

[Is it going to save me $50/month for 100 months -- 8.3 of the 10 year
warranty?  (Hint, our bill this month was $100; I'm pretty sure >> 50% of
it was NOT cooling -- I'll have a *real* handle on this, in the future!)
Compound this with things like "how long do you expect to live in the
home?" and "can you recover any of the cost of the installation when/if
you sell the home?" and these sorts of big investments see questionable
analysis]

Instead, people nibble at the edges.  "What can I do with $100?"
Yet, will *forget* things that are dirt cheap to do (replace filters,
clean condenser coils) unless explicitly reminded.

> The problem is that there is no EPA
> regulation requiring standardization of the trouble codes as there is
> in the automotive world.  That means that every brand's diagnostics
> are proprietary and that they won't be released unless forced to.
>
> The independent service tech is an endangered species because of the
> 10 year warranties and because of the proprietary nature of the
> systems.  There will be some bottom feeders (Rheem and Ruud for
> example) around for a few more years for use in cheap spec houses but
> they'll be pushed out by more and more stringent SEER regulations.
>
>> I'd wager the light comes on after a fixed number of "blower hours".
>> It knows nothing of the quality of filter installed, the amount of
>> dirt/dust in the edifice, the pressure drop across its surface, etc.
>
> You would lose that wager in most cases.

So, it watches for a delta-P across the filter?  (note we're not just
talking about your little splits!)

>> Do you have any idea the number of brands, models and variations there
>> are on the market of cars?  coffee pots?  personal computers?  cell
>> phones?  televisions?  Does any of that prevent owners of those
>> bits of kit from sharing their failure/repair experiences?  Does
>> it prevent those devices THEMSELVES from sharing their experiences
>> without requiring the owner/repairman to take explicit actions?
>
> with the exception of cars (where the diagnostics are standardized by
> law), none of the other items are repaired anymore except maybe by a
> few nerds.   I mean, would you really waist your time repairing a $15
> coffee pot?

Did you miss "personal computers, cell phones, televisions"?
Granted, there are large swaths of The Public that will almost WELCOME
an opportunity to replace something as a chance to "buy new"... but,
that doesn't apply universally.  Do you want to replace your $2K television
when its 2Yr warranty has expired and it shits the bed?

You're also ignoring the fact that automata can share those experiences
directly -- *if* they can "talk" to each other (or a central knowledgebase).
They don't need the involvement of a technician nor the approval of a
manufacturer (so long as I don't open any "warranty seals").

You claimed units are already doing this.  But, only to the advantage of the
"major manufacturers"; the user is out of the loop.  Why can't *my* HVAC
system share information with other HVAC systems?  And, in concert, let
them decide which things are "universal truths" -- instead of locking
that data up inside a "major manufacturer's" knowledgebase (requiring me
to use one of his "authorized agents" to effectively gain indirect
access to it)

The Internet is empowering because it allows information to be shared
that might otherwise be difficult to share *or* difficult to LOCATE.
Because the information was removed from the exclusive domain of The Few
and made available to The Many.

>> Do you think your car doesn't "tattle" on what its noticed about
>> its performance and your driving patterns when it visits the dealer?
>> Do you think the dealer -- and manufacturer -- DISCARD that information?
>
> Well, I helped design the http://www.megasquirt.com aftermarket EFI,
> used to run a tuner shop on the side, published a magazine called
> Performance Engineering that dealt primarily automotive high tech,
> used to hack GM PCMs for use on other engines (there is a very private
> mailing list where fellow EFI hackers share their exploits), own a
> very sophisticated OBD-II gateway and the software that goes with it
> so yes, I have a clue as to what data is exchanged via the OBD-II bus
> at the dealership or independent garage.
>
> BTW, if you have any real interest in this area, I strongly recommend
> the TriCAN gateway from this guy
>
> http://www.obd-2.com/

Sorry, I have far too many things on my "WANT to do" list to be able to
afford adding any other "interests"!  :<  Years ago (as a kid), I was
interested in building CDI's, instrumenting the carburetor (before EFI),
automatically cutting out the ACbrr compressor when the engine load
increased, etc.  Now, I'll let folks with bigger budgets do that sort
of thing.

[I met a guy many years ago who (lets see how I can say this diplomatically)
would modify *new* engines (including removing and adding metal to the block,
etc.) and tweak the ECU's based on how THOSE modifications altered the
engine's performance on *his* dyno.  Then, once satisfied, would "make it
look factory new, again" (technically, its never been *in* a vehicle) and
resell it for many kilobucks.  It should be obvious who his customers were!
It was fascinating to see how such little tweaks could have demonstrable
differences in performance ("why aren't they ALL made like that?") as
well as the fact that this sort of thing was actually *done*!  <grin> ]

> The software is free and will give you a real education on the state
> of government-mandated standardization.  The powertrain codes (the
> 1000 series) has been standardized by statute but none of the rest of
> the stuff that travels on the bus has been.  Things like ABS,
> stability control, cabin environmental control and even thing such as
> tail light modules chat on the CAN bus.  The manufacturers will
> release some of these so-called "extended" coded for a price.  GM's
> was $700 last time I checked.
>
> George Peper, the guy behind obd-2.com, pays for the all the extended
> code sets and incorporates them into his free software.  He's probably
> the world's foremost expert on multi-brand OBD-II technology.
>>
>> Why can't other INTERNETWORKED devices similarly share information?
>> Why does connectedness just mean "able to be controlled remotely"?
>
> Because it makes no economic sense to do so.

Why not?  Because it costs money to talk to something?  But, the HVAC
plant already talks to the thermostat.  If the thermostat can talk
to OTHER things (including the outside world), why let the data
stop, there?

Why require the HVAC plant to talk to the thermostat over a few dedicated
#18AWG conductors in a signaling cable?  Why can't it send *messages*?
And, if *it* can send messages, why should it be limited to only talking
to the thermostat?  Why shouldn't it be able to query the local atmospheric
conditions?  Or, determine household occupancy?  Or, the current electricity
consumption to alter *when* it ELECTS to engage the compressor/blower
(ToU/demand)?

Ans:  because the HVAC vendor isn't horizontally integrated enough to
have access to those "hooks" -- nor can they expect their customers to
have those hooks in place, already.

> The major manufacturers'
> diagnostic systems collect diagnostic data and sends it back to the
> manufacture when the tech connects to the net.  In other words, what
> you're proposing is already happening.

Is there a tech sitting *at* each unit 24/7/365?  I.e., the manufacturer only
sees data when a *tech* facilitates the conveyance of that data to them.
And, because of that, only sees as much data as the HVAC system can BUFFER
within.  You can't ask it:  "what were the observations on 1/1/17 and
how do they compare to 1/1/16?"

Those devices don't report 24/7/365 because they can't count on having
a means *to* communicate!  They don't have built in SMS capability
because it would be too costly to add that JUST to send data back in
real time.

OTOH, if you already *have* that infrastructure in place, the cost
of exploiting it is negligible.

Said another way, if YOUR <whatever> (ACbrrr, car, pacemaker, etc.) had the
ability to monitor <whatever> variables 24/7/365, would you deliberately
DISCARD this data?  ("I don't care how it was performing yesterday; all I
care is how it is NOT performing, today!")  Do you think all failures are 
independent events unrelated to past performance?

Referencing the "conclusions" reported in the paper at the top of
this post, do you think those "failed" systems magically failed overnight?
*Gained* a pound of refrigerant?  Or *lost* a comparable amount?
Had the technician turned up, unannounced, a few days earlier, would
he NOT have seen data that indicated these failures, at THAT time?
Or, two months before that?  etc.

>> Exactly *zero* of the ~200 homes in this subdivision have deviated from
>> the "single, central compressor" cooling system (I walk the neighborhood
>> daily).  One of the businesses that I visit has installed them (small
>> compressor/condenser on the rooftop; evaporator an eyesore on the wall
>> in each office space.
>>
>> By contrast, perhaps 20% now have roof-mounted photovoltaics.  And,
>> probably 25% of the homes with pools have passive solar (pool) water
>> heating.
>
> The government pays huge subsidies for solar installations.  Not so
> for more efficient HVAC.  The result is evident in your neighborhood.
> If the government ever offered HVAC upgrade subsidies (as a fiscal
> conservative I hope they never do), you'd see the same thing happen as
> with solar.

I.e., folks don't upgrade their HVAC because the cost to THEIR wallet
far exceeds the *perceived* savings (as I mentioned, above).  Just
like the guy who drives a beat up old pickup truck instead of a
new Prius (or, new *anything*).  He might know (and admit) that it
would be the better practice, but that knowledge isn't enough to offset
the resistance that his wallet puts up!

>> What do you do when you have no basement nor attic through which to run
>> that branch circuit?  Or, when you have to add a sub-panel to accommodate
>> the extra circuits (fed by the "old" compressor circuit)?  And, the walls
>> are concrete/slump block.
>
> I'd do the same thing that they did over at the Cambell School.  Bury
> NM cable around the outside perimeter of the building.
>
> Bitching about maybe having to use a subpanel is a bit trite, wouldn't
> you agree?

Its all *cost*.  Remember my comments re: "wallet resistance"?
There's a reason folks design "drop-in replacements" for <whatever>.
Every bit of extra effort turns into resistance to adopt the change.

Our clothes dryer has a water hookup.  You *know* that there can't
be many (any?) homes out there with THREE water connections in their
laundry areas!  So, the dryer manufacturer has to provide an
adapter that lets the dryer piggy-back on the washing machine's
connection.  If he tells the customer to make a trip to the local
hardware store to purchase it, the user will probably never install
that connection.  And, thereafter, in word-of-mouth discussions
(with potential future dryer purchasers) the dryer's capabilities
that rely on that water line will be seen as "unnecessary increases
in sales price" -- because the current owner has apparently not
USED them!

>> Shrubbery?  We live in the *desert*.  You want me to have one of these for
>> the living room (maybe it can bleed over into the dining room, as well).
>> Another for the kitchen and family rooms.  Something else to address the
>> bedrooms (in concert?) -- and hope the spillover handles the other
>> common spaces.  And, no one will notice these changes to the interior
>> or exterior of the house?
>
> Believe it or not, the entire world isn't like where you live.

Nor is it like where *you* live.  So, expecting people to adopt YOUR solution
to THEIR problem is a bit pretentious.  Just like expecting one ACbrrr unit
to be operated -- or perform -- identically to others, in other applications.

> Maybe a swamp cooler does you better.  I claim no knowledge of
> environments other than the Southeast.

I've lived in several parts of the country -- with varying types of HVAC
supplies (bottled gas, heating oil, evap coolers, ACbrrrs, steam, hot
water baseboards, electric baseboards, radiant floors, exhaust fans, etc.).
The fault many people make is in thinking that they operate the same way.

E.g., GFA is very responsive; OTOH, air with low heat content needs to
be delivered at a slower rate than hotter air (lest it feel COLD).
Oil-fired water is very slow to respond, but provides a more uniform
environment.

In one (whole-house) exhaust-fan equipped home, running the fan for
5 minutes with the windows opened on the lowest level of the house
would quickly drop the interior temperature -- far more economically
than running the ACbrrr to accomplish the same task (so: open windows,
run fan, close windows & fan, turn on ACbrrr).

But, a "thermostat" (the traditional device used for controlling
HVAC systems) can't know all of these things.  And, even if designed
to *accommodate* them, getting the necessary configuration data from
the user isn't convenient nor reliable (e.g., for how much hysteresis
is YOUR thermostat configured?)

You want to be able to draw on information from other "providers"
AND be able to convey more than is possible with a blinking light
or even a TINY graphic display.

But, you don't want to bear the cost for doing so for JUST your
HVAC system.  Or <whatever>.

And, if you can't be assured to have those hooks/capabilities
available, then the approach you take to solving the problem is
burdened by THOSE "can be met" assumptions.

OTOH, if you *know* that you have a way to integrate "services"
from different providers AND involve the user in more productive
ways, you can take an entirely different approach to solving ALL
of those problems.

When cars moved beyond the "idiot light" approach to communicating with
their driver, the interface got much richer and the interaction more
meaningful (e.g., "Place car in park" instead of just letting the
driver shut the engine off while leaving the car in gear).

In a car, you have one manufacturer that can coordinate the interactions
of all subsystems (even if implemented by different vendors).  That
hasn't happened in the home.  Because no one represents the "home"
or the "homeowner"; they're all just "third party vendors" as far
as the house is concerned.

So, the swamp cooler, ACbrrr, furnace, humidification/dehumidification,
air purifier, roof vents, etc. all act as independent entities and
the "thermostat" (aka nominal environmental control system) can't
exploit any of those capabilities -- to the advantage of the homeowner!

>>> There is a place in Brasstown Bald, NC called the Cambell School for
>>> the arts and crafts (or something like that) that is situated on a
>>> large 19th century farm.  Many of the buildings are made of stacked
>>> and cemented river rock.  Mini-splits have been installed in all the
>>> buildings.  They had someone paint the condensing units and the single
>>> line that goes indoors to match the surroundings.  I would have never
>>> known they were there had I not see an air handling unit hanging on
>>> the inside wall of one of the buildings.
>>
>> And, who *paid* for all this?
>
> Do you have a point to make?  Of course the school paid for it.  It
> was a choice of either no environmental controls in a part of the
> country that goes below 0 in the winter and is swelteringly hot and
> humid in the summer and having a very efficient and non-obtrusive
> system that makes the building habitable.  That should be obvious to
> you.

There are many ways to address those needs -- as I'm sure the school existed
long before the units you're citing were installed!  Prior to that point,
did the students and faculty "freeze and perspire"??  Did they close the
school in intemperate months?

Did all of that kit FAIL the day before it was replaced?  Someone planned
that the school *could* reap the benefits from the choice of "solution A"
over "solution B".  I suspect the individual teachers and staff didn't
consider whether THEY would be at the school when the (ROI) payback came
about.  *But*, folks acting on behalf of the school -- a considerably
longer-term entity than a homeowner in his "maison-du-jour" (13 year
average length of stay in a home -- and that assumes you make these
updates EARLY in your residency; not after 5-10 years when you're more
likely to be moving out)

>> Our next home will be below grade -- because it is just silly NOT to
>
> Good for you.  Mine was going to be too until time slipped away and I
> got too old to make it happen.  I own the perfect property.  60 acres
> of forested land with a spring fed 5 acre lake.  A nice slope on one
> side where the underground house could have been build and enough flow
> from the springs to use micro-hydro generation to be off-grid.  And,
> of course, the lake to use for the water-sourced heat pump(s).

I've no desire to be maintaining generation/cooling/heating facilities
as I age.  I'm more interested in solutions that just inherently
"work" (below grade, south-exposures with suitably constructed
overhands to shade summer sun but not winter, etc.).

Likewise, I don't want to have to rely on remembering all of the
things I should be doing each month/year to keep the house "up".
Just like I don't want to have to remember the last time I changed
the oil in the car, etc.

> <much irreverent to the thread stuff deleted>
>
>> I think we're paying about half that.  We'd save more by discarding the
>> freeezer (sitting out in the garage), unplugging the various wall-wart
>> powered devices scattered around the house (even at < 1W/each, having
>> dozens of them adds up!) and forcing the computers to "sleep" more
>> aggressively (there are 4 computers running, currently; two actively in
>> use, another servicing my network, and a fourth waiting for me to finish
>> this post so I can get back to "work").
>
> I pay 12 cents/kWh so such petite optimizations aren't worth my
> effort.  Changing out my (maybe) 10 SEER central unit with leaky duct
> work with mini-splits is.  I'm currently buying kits as spare change
> allows and storing them in the basement.  Probably do the conversion
> next year.  Payback will be about 4 years.  My contractor discount is
> 50% so I pay half what you would pay from one of the internet vendors.

And, your labor costs are "free".  So, the 4 years is probably closer
to 8.  For "average folks" who tend to live in a place 13 years?  *Most*
of that 10 year warranty?

Are you sure you won't be "forced" into an assisted living solution
before the payback?  Or, coerced by your other half?

[I finished remodeling SWMBO's place just before she opted to move, here!]

>> But money is only part of the equation.  There's also comfort/convenience
>> (its no fun to lose cooling/heating when you NEED it -- and, you only know
>> that it is gone BECAUSE you need it!).  And, there is the "independence"
>> factor:  being able to continue to live in your own home (vs. a retirement
>> home or assisted care facility) without having to keep a lengthy list of
>> all the "things" you should be checking on -- or hiring someone to check
>> on FOR you.
>
> You just made the case for multiple mini-split systems that provide
> multiple redundancy and have no single point of failure.

How does it help if your bedroom is cool but your living room isn't?
Great if you're asleep.  Not so much if you're entertaining guests!

>> Do you regularly visit your folks (or kids!) to ensure the house is "intact"
>> to address their anticipated needs for the next month (or five)?  Do
>> *they* remember to change the filter in their furnace?  Or, have the
>> compressor serviced?   Check the evaporative cooler for leaks?  etc.
>> It's April -- time for me to make my annual survey of the condition of
>> the roof (so I can affect repairs before it gets too hot *or* Monsoon
>> starts)...
>
> I would if I still had any of those people.

What do those folks (like you) do who don't have folks to look after them?
Ans:  move into a retirement home/community and outsource all of those
responsibilities (for a hefty price).  Here, its not uncommon to have
a few hundred $K "buy in" with $3-4K/person on an ongoing monthly basis.

And, no guarantee that you'll be able to *stay* there.  Many places
can't address any sorts of medical needs, alzheimer's, etc.  Other
places may opt to move you *out* to accommodate their business plans
("We're going to raze the building you're in and erect another on
that spot.  You can buy back in AFTER its completed -- but, for now,
you'll have to find other accommodations...")

>> Wouldn't it be nice if those things could remind them of these needs?
>
> Why, when an entry in the calendar of their cellphone to have the
> system serviced would do the same thing?

John, I truly hope you are never "blessed" with memory or physical
problems.  And, never have to deal with folks who are!  You may
find an extraordinary sense of resentment for just how helpless you
WILL be in those situations; helpless to take care of yourself *or*
to find "things" that you can rely on to lessen that effort.

You may, then, appreciate work that others have done to make
your later life easier (or, you can just become a grouchy old man
who resents his losses).

> OK, I'm finished with this thread.  I hope other readers have gleaned
> some helpful info.

Ditto.  I know what I need to do.  Feel free NOT to ever avail yourself of
any such "technological advances" -- including the NEXT model ACbrrrs
that are made available AFTER you've installed yours!

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#454507

On 3/31/2017 3:08 PM, Neon John wrote:
> On Thu, 30 Mar 2017 14:31:35 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
>
> As an engineer who has operated an industrial/commercial refrigeration
> business on the side for most of his career,  I'll take a shot.
>
>> What can I learn (in absolute and relative terms) from monitoring
>> the temperature and pressure in high and low side coolant lines
>> to the ACbrr's evaporator coil?
>
> I have no idea what "ACbrrr" is but I'll guess that you're speaking of
> the HVAC on a modern car.

No, in a home (modern or otherwise)

> The answer to your question is essentially "absolutely nothing".  An
> extreme lack of refrigerant will manefest itself as little to no
> cooling but you'll probably have already gotten a CE light by then.
>
> If you are low on refrigerant you can't just "dump in a blow-off can"
> and hope for the best as in the old days.  The system should be
> drained, evacuated and charged to the nameplate weight of refrigerant.
>
> The reason I said "absolutely nothing" is that a modern car may have
> all or part of the following:
>
> computer controlled expansion valve
> computer controlled or not evaporator back pressure regulating valve
> (GM parlance: POR valve)
> computer controlled or not variable displacement compressor
> computer controlled variable speed condenser and evaporator fan.
> high and low side pressure and temperature sensors.
>
> All of this sophistication is in an effort to squeeze that last
> hundredth of an MPG CAFE rating.

But that's NOT the case in homes.  And, I suspect far more energy is
expended cooling tens/hundreds of thousands of cubic feet in a home
than the hundreds of cubic feet in vehicles!

*Businesses* have additional instrumentation (available) on their
HVAC plants.  But, that hasn't manifested in the home, yet.

I've seen studies estimating that "the vast majority" of home plants
are operating 10-20% below their expected level of efficiency.
Why buy a 12 SEER unit and operate it at the efficiency of a 10?

The "concerned homeowner's" only remedy is to call a heating/cooling
contractor and HOPE you get a tech who knows more than just
rule-of-thumb guidelines.  (And, you can almost be guaranteed
that he'll say you need *something* done, now that he's made the
trip!)

OTOH, if you have instrumentation that can watch the (HVAC) system
ALL THE TIME (in much the same way that an automobile does -- and
for similar reasons), then it can notice trends and advise the consumer
(with more than an "idiot light"):
- "Please replace the air filter in your furnace blower"
- "Please clean the condenser coils"
- "Please call a service man to clean the evaporator coils"
- "The running current on the compressor has steadily increased
   to a point suggestive of imminent failure.  Please call for service"

(e.g., "Click here for a sample video illustrating how this is done")

It can likewise note when a plant has been poorly sized and adjust
the control algorithm to enhance comfort *or* increase energy efficiency.

"Human beings" don't seem well suited to these sorts of activities,
unaided/unadvised.

> The car's computer (known as the PCM or powertrain control module) can
> take measurements and compare them to built in models to determine if
> the CE light should be lit.  The dealer's diagnostic console can set
> up standard conditions and do more rigorous testing.  You can't do
> that as a user.
>
> In the old days, I'd fully load the system by either opening the doors
> in the summer or putting a couple of 240 volt heaters in the front
> seat in winter and then look at the evaporator superheat to begin with
> my testing.  The back pressure regulating valves spoiled that method.
>
> Another method that I use that I've never seen used anywhere else is
> to don a mechanic's sthethescope and then press the probe HARD against
> the expansion device.  Stressing the diaphragm acts as a high pass
> filter and eliminates most of the engine and compressor sounds.
>
> I can then listen to the flow of the refrigerant through the expansion
> device.  With plenty of refrigerant, it sounds like water flowing in a
> pipe.  With a large lack of refrigerant, only the sound of gas flowing
> will be heard.  If the charge is intermittent and/or on some vehicle
> system designs, a mixture of fluid and gas bubbles can be heard.
>
> One has to carefully mix gauge readings, expansion device sounds,
> temperatures and experience to figure out the system status.
>
> One technique I use is to charge about an ounce of refrigerant and
> listen to the change in sound of the expansion device.  If it doesn't
> change and the sound is that of a mixture of bubbles and fluid and
> everything else seems normal, I usually conclude that the system was
> designed to operate in starved mode.
>
> The most difficult to diagnose is a worn but not failed compressor.
> I'm not a "parts changer" so I try to diagnose the compressor by
> varying the load (heaters in the cabin) and comparing the pressures
> and temperatures to the compressor OEM's charts.
>
> Given the declining quality of high school grads that make up most
> HVAC shop employees, few shops attempt much in the way of diagnosis.
> They'll evacuate the system (for which you're charged an environmental
> recovery fee while the company sells the used refrigerant for
> recycling), change the expansion device and the filter/dryer and
> recharge the system.  If that doesn't fix the problem, out comes the
> refrigerant again (another fee) and the compressor gets changed.  If
> that doesn't fix the system, the tech punts to the shop owner who
> usually does have a clue.
>
> Some enterprising techs will actually check the condenser to see if it
> is dirty and needs cleaning.
>
> So the AC system in a modern car is pretty much like everything else
> on the vehicle - if you're not a dealer or have a $4-10k aftermarket
> diagnostic system (plus $1000/year updates), you just can't do much.

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#454529

On Fri, 31 Mar 2017 16:06:19 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:


>> All of this sophistication is in an effort to squeeze that last
>> hundredth of an MPG CAFE rating.
>
>But that's NOT the case in homes.  And, I suspect far more energy is
>expended cooling tens/hundreds of thousands of cubic feet in a home
>than the hundreds of cubic feet in vehicles!

Actually there's as much pressure from the government to increase
residential SEER as there is CAFE on the auto makers.

>I've seen studies estimating that "the vast majority" of home plants
>are operating 10-20% below their expected level of efficiency.
>Why buy a 12 SEER unit and operate it at the efficiency of a 10?

Why operate a 12 SEER unit with a 28 SEER unit is available at a
reasonable cost.

>OTOH, if you have instrumentation that can watch the (HVAC) system
>ALL THE TIME (in much the same way that an automobile does -- and
>for similar reasons), then it can notice trends and advise the consumer
>(with more than an "idiot light"):
>- "Please replace the air filter in your furnace blower"

An idiot light is sufficient, something most modern systems have.

>- "Please clean the condenser coils"

dirty coils, failing condenser fan motor or corroded fan blades?

If your answer is "delta-p across the condenser", several
manufacturers tried that in the 90s to trigger the defrost cycle
during heating.  The signal is too small for a cost-effective (by HVAC
standards) to reliably sense and a reliable sensor is too expensive.

>- "Please call a service man to clean the evaporator coils"

Dirty filters, failing evaporator fan motor, eroded fan blade or dirty
coil?

>- "The running current on the compressor has steadily increased
>   to a point suggestive of imminent failure.  Please call for service"

A compressor rarely fails electrically unless it's a catastrophic
failure caused by a failed run cap and welded-stuck thermal overload.

The run current stays close to the same.  That's because the
compressor is still compressing the refrigerant - doing work on it -
but the refrigerant leaks back past the piston/rotor/scroll.

Noise analysis is the usual technique to detect a failing compressor.
A bit expensive for home use.

John

John DeArmond
http://www.neon-john.com
http://www.tnduction.com 
Tellico Plains, Occupied TN
See website for email address

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#454541

On 3/31/2017 5:53 PM, Neon John wrote:
> On Fri, 31 Mar 2017 16:06:19 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
>
>>> All of this sophistication is in an effort to squeeze that last
>>> hundredth of an MPG CAFE rating.
>>
>> But that's NOT the case in homes.  And, I suspect far more energy is
>> expended cooling tens/hundreds of thousands of cubic feet in a home
>> than the hundreds of cubic feet in vehicles!
>
> Actually there's as much pressure from the government to increase
> residential SEER as there is CAFE on the auto makers.

But cars (are perceived to) "wear out" a lot quicker and are more LIKELY
to be replaced than HVAC systems.  You don't *see* what your HVAC system
is costing you.  You *do* see what your car costs -- each time you
fill the tank!

>> I've seen studies estimating that "the vast majority" of home plants
>> are operating 10-20% below their expected level of efficiency.
>> Why buy a 12 SEER unit and operate it at the efficiency of a 10?
>
> Why operate a 12 SEER unit with a 28 SEER unit is available at a
> reasonable cost.

What's reasonable to some might be unaffordable to others.

Is your computer more than two days old?  Why haven't you replaced it?
Clearly, there are faster and cheaper units on the market, today,
that weren't available two days (or more!) ago!

It's only money.  And time.  And aggravation.  And inconvenience.  etc.

>> OTOH, if you have instrumentation that can watch the (HVAC) system
>> ALL THE TIME (in much the same way that an automobile does -- and
>> for similar reasons), then it can notice trends and advise the consumer
>> (with more than an "idiot light"):
>> - "Please replace the air filter in your furnace blower"
>
> An idiot light is sufficient, something most modern systems have.
>
>> - "Please clean the condenser coils"
>
> dirty coils, failing condenser fan motor or corroded fan blades?

Hey, I'm sure I can come up with an even LONGER list of possible
problem causes.  Shall we try to see who's list is LONGEST?

We have these remarkable things called COMPUTERS.  They can walk AND
chew gum at the same time!  They can also prioritize likelihoods of
individual problem causes.  And, (user) "costs" of exploring each
of those possible causes ("Yeah, its unlikely that the circuit breaker
has tripped -- BUT, it's really easy for a user to check that!
Much easier than checking to see if the compressor is bound or the
run cap failed!  So, lets present that as the first step in the
troubleshooting tree...")

The goal isn't to put HVAC guys out of business.  Rather, the goal is
to minimize costs and maximize comfort/convenience for the *user*!

A few winters ago, we lost "heat".  Wanna start a list of possible
causes?  Let's arrange them in order of likelihood.

The ACTUAL reason for the failure was because the natural gas
pipeline feeding our CITY couldn't keep up with demand.  So,
pressures fell to a point where a sustained flame couldn't
be achieved in most furnaces.

*Every* HVAC contractor was booked solid with service calls.
All those homeowners waking up to cold homes.  Did the contractors
think to tell the folks calling in that "The city's gas supply has
'failed'.  Please be patient.  Contact the gas company for more
information.  If you REALLY want us to come out to examine your
plant, we will.  But, be advised that there WILL be a service
charge -- even if we find nothing wrong on site!"

In *our* case, I noticed the furnace repeatedly trying to light.
Pulled off the access panel and saw a weak flame that would
quickly be squelched (as the gas valve was explicitly closed;
flame sensor hadn't detected the weak flame!).  Called a neighbor
to see if THEY had heat.
     "Gee, what's the likelihood that BOTH of our furnaces would
     fail at the same time?"

No service call.  No expense.  Just wait until the utility comes
back on line.

If the furnace could have SPOKEN to me, it could have suggested
to me that either:
- gas line was constricted
- gas valve had failed (closed)
- flame sensors had failed
- controller had crashed
- gas had been turned off (did you remember to pay last month's bill?)
...
- city suffering from a system-wide shortage

Instead, it just sat in an idiot loop waiting for things to magically
resolve themselves.

> If your answer is "delta-p across the condenser", several
> manufacturers tried that in the 90s to trigger the defrost cycle
> during heating.  The signal is too small for a cost-effective (by HVAC
> standards) to reliably sense and a reliable sensor is too expensive.
>
>> - "Please call a service man to clean the evaporator coils"
>
> Dirty filters, failing evaporator fan motor, eroded fan blade or dirty
> coil?
>
>> - "The running current on the compressor has steadily increased
>>   to a point suggestive of imminent failure.  Please call for service"
>
> A compressor rarely fails electrically unless it's a catastrophic
> failure caused by a failed run cap and welded-stuck thermal overload.
>
> The run current stays close to the same.  That's because the
> compressor is still compressing the refrigerant - doing work on it -
> but the refrigerant leaks back past the piston/rotor/scroll.
>
> Noise analysis is the usual technique to detect a failing compressor.
> A bit expensive for home use.

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#454546

On Fri, 31 Mar 2017 19:38:51 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

>On 3/31/2017 5:53 PM, Neon John wrote:
>> On Fri, 31 Mar 2017 16:06:19 -0700, Don Y
>> <blockedofcourse@foo.invalid> wrote:
>>
>>>> All of this sophistication is in an effort to squeeze that last
>>>> hundredth of an MPG CAFE rating.
>>>
>>> But that's NOT the case in homes.  And, I suspect far more energy is
>>> expended cooling tens/hundreds of thousands of cubic feet in a home
>>> than the hundreds of cubic feet in vehicles!
>>
>> Actually there's as much pressure from the government to increase
>> residential SEER as there is CAFE on the auto makers.
>
>But cars (are perceived to) "wear out" a lot quicker and are more LIKELY
>to be replaced than HVAC systems.  You don't *see* what your HVAC system
>is costing you.  You *do* see what your car costs -- each time you
>fill the tank!

Huh?  HVAC systems last about ten years (I had to replace much of mine
after three).  Cars last longer than that these days.

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