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Re: Window Heater

From rickman <gnuarm@gmail.com>
Newsgroups sci.electronics.design
Subject Re: Window Heater
Date 2017-03-01 19:44 -0500
Organization A noiseless patient Spider
Message-ID <o97pp0$59v$1@dont-email.me> (permalink)
References <o7oj4r$9vu$1@dont-email.me>

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On 2/11/2017 10:02 PM, rickman wrote:
> I sit directly under a window much of the time (don't suggest I move,
> there just isn't another practical option).  When it is cold the window
> has a draft that is downright brutal.  I plugged the window with a 3/4
> inch piece of Styrofoam insulation and the draft persists (sealed with
> tape around the edges).  Seems even a couple of degrees difference with
> the room air can create a draft that is cold enough to be a bother. The
> wall around the window reads 66 degrees while the Styrofoam reads about
> 64 degrees.
>
> I thought maybe the way to deal with the draft is to fight cold with
> fire.  So I bought a few power resistors in the metal cases that can be
> mounted.  I wired them in series and connected a variable supply as I
> didn't know how much power I would need.  Turns out a fair amount.  If I
> crank up the heat to around 30 to 40 watts with the resistors right
> behind me on the sill of the window, the draft is gone.  Not bad.
>
> But I was wondering how best to mount them.  At this wattage they get
> pretty warm, around 200 degrees!  I was looking at sheet aluminum to
> mount them to thinking just a couple/three inches of height would do the
> job.  But now I am wondering.  I'm not sure a string of resistors along
> a three inch wide sheet of aluminum would reduce the temps that much and
> I'm not at all clear on how that might affect the airflow.
>
> I am thinking of a much wider sheet that would not get so hot.  I am
> also thinking it would help better to cut the draft by being larger. I'm
> thinking it would give rise to a reverse draft and possibly require less
> heat.
>
> So which is better, a small hotter heat source or a spread out lower
> heat source.  I suppose covering the entire windows with aluminum would
> be the best approach, but I'm not ready to do that.  So maybe 12 inches
> of aluminum sheet?

So I got the power supply in and hooked it up.  This is a laptop type 
supply with a switch for 12 to 24 volts output.  Driving a 10 ohm load 
that produces 14.4 to 57.6 watts.  With the old unit at 20 volts it was 
more than warm enough for a cold night.  This one will surely do the job 
if it doesn't blow up.  I ordered more resistors which I will connect to 
get a 6 ohm load for the full rated 96 watts.  We'll see if the power 
pack dies with that high a load.  There are some colds nights ahead in 
spite of the present 70 degree days.  Very strange weather for February.

The supply is about the same size as my Toshiba brick, but MUCH lighter, 
so obviously not so much magnetics.  I wonder what the quality is like 
inside?  How would you make a 96 watt DC power supply that weighs less 
than 6 oz including the corded EMI filter?

-- 

Rick C

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Thread

Window Heater rickman <gnuarm@gmail.com> - 2017-02-11 22:02 -0500
  Re: Window Heater bill.sloman@ieee.org - 2017-02-11 20:57 -0800
    Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 01:02 -0500
      Re: Window Heater whit3rd <whit3rd@gmail.com> - 2017-02-11 23:07 -0800
        Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 03:52 -0500
          Re: Window Heater whit3rd <whit3rd@gmail.com> - 2017-02-12 18:32 -0800
            Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 21:42 -0500
              Re: Window Heater "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-13 10:04 -0600
                Re: Window Heater makolber@yahoo.com - 2017-02-13 10:17 -0800
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-13 15:30 -0500
                Re: Window Heater "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-13 15:39 -0600
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-13 20:28 -0500
                Re: Window Heater krw@notreal.com - 2017-02-13 20:48 -0500
                Re: Window Heater Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-13 13:47 -0800
            Re: Window Heater dagmargoodboat@yahoo.com - 2017-02-14 06:56 -0800
              Re: Window Heater "dcaster@krl.org" <dcaster@krl.org> - 2017-02-14 07:17 -0800
                Re: Window Heater dagmargoodboat@yahoo.com - 2017-02-14 13:20 -0800
                Re: Window Heater George Herold <gherold@teachspin.com> - 2017-02-14 16:17 -0800
                Re: Window Heater "dcaster@krl.org" <dcaster@krl.org> - 2017-02-14 16:28 -0800
                Re: Window Heater George Herold <gherold@teachspin.com> - 2017-02-14 17:42 -0800
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-14 21:18 -0500
                Re: Window Heater dagmargoodboat@yahoo.com - 2017-02-14 19:20 -0800
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-14 22:42 -0500
                Re: Window Heater George Herold <gherold@teachspin.com> - 2017-02-15 06:51 -0800
                Re: Window Heater "dcaster@krl.org" <dcaster@krl.org> - 2017-02-15 06:06 -0800
                Re: Window Heater George Herold <gherold@teachspin.com> - 2017-02-15 06:54 -0800
                Re: Window Heater "dcaster@krl.org" <dcaster@krl.org> - 2017-02-15 09:15 -0800
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-15 15:02 -0500
                Re: Window Heater "dcaster@krl.org" <dcaster@krl.org> - 2017-02-15 16:38 -0800
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-15 19:50 -0500
                Re: Window Heater Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-17 11:18 +0000
                Re: Window Heater Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-16 08:28 +0000
              Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-14 14:07 -0500
                Re: Window Heater dagmargoodboat@yahoo.com - 2017-02-14 12:57 -0800
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-14 17:32 -0500
                Re: Window Heater dagmargoodboat@yahoo.com - 2017-02-14 19:12 -0800
              Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-14 14:16 -0500
                Re: Window Heater dagmargoodboat@yahoo.com - 2017-02-14 12:53 -0800
                Re: Window Heater John S <Sophi.2@invalid.org> - 2017-02-14 16:14 -0600
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-14 17:35 -0500
                Re: Window Heater John S <Sophi.2@invalid.org> - 2017-02-15 10:45 -0600
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-15 15:06 -0500
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-15 16:46 -0500
                Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-14 17:34 -0500
      Re: Window Heater bill.sloman@ieee.org - 2017-02-12 04:57 -0800
        Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 18:19 -0500
      Re: Window Heater Winfield Hill <hill@rowland.harvard.edu> - 2017-02-12 10:42 -0800
        Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 18:30 -0500
    Re: Window Heater Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-12 08:45 +0000
      Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 03:57 -0500
        Re: Window Heater Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-12 09:34 +0000
  Re: Window Heater Jon Elson <elson@pico-systems.com> - 2017-02-11 23:52 -0600
    Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 01:07 -0500
      Re: Window Heater Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-14 10:40 +0000
        Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-14 06:00 -0500
          Re: Window Heater John S <Sophi.2@invalid.org> - 2017-02-14 16:17 -0600
            Re: Window Heater Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-14 14:28 -0800
            Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-14 17:36 -0500
  Re: Window Heater Mikko OH2HVJ <mikko.syrjalahti@nospam.fi> - 2017-02-12 14:54 +0200
    Re: Window Heater Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-12 08:56 -0700
      Re: Window Heater Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-02-12 20:14 +0200
        Re: Window Heater Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-11 00:30 -0500
    Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 18:56 -0500
  Re: Window Heater "dcaster@krl.org" <dcaster@krl.org> - 2017-02-12 06:35 -0800
    Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 19:01 -0500
      Re: Window Heater "dcaster@krl.org" <dcaster@krl.org> - 2017-02-12 17:29 -0800
        Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 21:37 -0500
          Re: Window Heater Jon Elson <jmelson@wustl.edu> - 2017-02-13 15:08 -0600
            Re: Window Heater Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-13 13:32 -0800
  Re: Window Heater Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-12 08:20 -0800
  Re: Window Heater "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-12 11:48 -0600
    Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 19:03 -0500
      Re: Window Heater "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-13 09:58 -0600
        Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-13 15:33 -0500
          Re: Window Heater Jon Elson <jmelson@wustl.edu> - 2017-02-13 15:10 -0600
            Re: Window Heater Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-13 13:36 -0800
            Re: Window Heater "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-13 15:40 -0600
            Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-13 20:34 -0500
          Re: Window Heater krw@notreal.com - 2017-02-13 20:52 -0500
  Re: Window Heater Tim Wescott <seemywebsite@myfooter.really> - 2017-02-12 12:02 -0600
    Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 19:05 -0500
      Re: Window Heater Tim Wescott <seemywebsite@myfooter.really> - 2017-02-14 17:49 -0600
  Re: Window Heater bitrex <bitrex@de.lete.earthlink.net> - 2017-02-12 13:06 -0500
    Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-12 19:05 -0500
  Re: Window Heater Clifford Heath <no.spam@please.net> - 2017-02-13 11:21 +1100
  Re: Window Heater krw@notreal.com - 2017-02-12 19:28 -0500
  Re: Window Heater Martin Riddle <martin_ridd@verizon.net> - 2017-02-12 21:57 -0500
    Re: Window Heater "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-13 10:01 -0600
  Re: Window Heater Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-13 13:49 -0800
    Re: Window Heater rickman <gnuarm@gmail.com> - 2017-02-13 20:36 -0500
  Re: Window Heater rickman <gnuarm@gmail.com> - 2017-03-01 19:44 -0500
    Re: Window Heater George Herold <gherold@teachspin.com> - 2017-03-01 17:33 -0800

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