lutful
Premium
join:2005-06-16
Ottawa, ON
 ·TekSavvy Solutions..
| heating ideas for a cold winter
It is time to do a complementary thread to this one:
»Cooling ideas for hot summers
A few new radios has survived -30C at our winter test site in Fort McMurray, Alberta where it went down to -50C in 2004.
In the past, we have done some standard thermostat controlled AC heating that can be sized for any enclosure and radio.
But it is often tough to get AC at remote nodes. Solar output also drops off tremendously in winter in northern latitudes.
We have also deployed some 48V PoE heater but even with 30W dedicated to heater, it is difficult to maintain 5C internal temperature when it is -40C ambient with 40km/h wind blowing on the enclosure.
IMHO the very best solution is a sealed thermo-nuclear battery that could easily supply ample heat and power for 20+ years.
But these are currently built in Idaho National Lab for NASA use and likely cost a million bucks. Until India or China starts selling them for civilian use, we have no hope.
So, please suggest all ideas - wild or not - for keeping radio enclosures warm in very cold winter climates. |
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40883644
Premium
join:2003-06-05
Parker, CO | This worked very well for us to -40.... Less then $3.00 a set in the volume we purchased them in.
--
Rich
»www.highgainantennas.com |
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lutful
Premium
join:2005-06-16
Ottawa, ON
·TekSavvy Solutions..
1 edit | As only a DYI, I paid $40 each just for the Canadian Thermostat controller device in 2004. 
Anyway we found from many field tests that a fixed thermostat setting does not work for all temperature and humidity scenarios to prevent condensation.
We are testing a dynamic dew-point based heater controller that uses the combined temperature and humidity sensor mentioned here: »Re: Environmental monitoring? |
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40883644
Premium
join:2003-06-05
Parker, CO | This worked very well for us  |
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lutful
Premium
join:2005-06-16
Ottawa, ON
·TekSavvy Solutions..
| I am curious what thermostat setting you used for that particular radio and enclosure size. What was the power budget for radio and heater?
Back in 2004, I used 8C fixed thermostat with hysteresis after doing some calculations for the Airaya PCB in Demarctech metal enclosure. |
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40883644
Premium
join:2003-06-05
Parker, CO
| Didn't use thermostat settings, they came pre-set 
The power budget was calculated by Scotty and every time I asked him what he used, I got the same reply:
I'm given it awl shesh gaawt captin
--
Rich
»www.highgainantennas.com |
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lutful
Premium
join:2005-06-16
Ottawa, ON | 1. Pre-set to what temperature? 0C , 5C, 10C, ... ?
2. How was that pre-set temperature chosen? |
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public
join:2002-01-19
Santa Clara, CA
·DSL EXTREME
| reply to lutful
said by lutful  :But it is often tough to get AC at remote nodes. Solar output also drops off tremendously in winter in northern latitudes. IMHO the very best solution is a sealed thermo-nuclear battery that could easily supply ample heat and power for 20+ years. Thermoelectric battery is not so good in the summer because it produces a lot more heat than electricity. There is no cold space to radiate unwanted heat into.
A wind turbine would work if it does not ice up.
But overall you also need to consider the summer heat in a "permanent" installation. |
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40883644
Premium
join:2003-06-05
Parker, CO
2 edits | reply to lutful
said by lutful :2. How was that pre-set temperature chosen? Have you ever played Chicken $hit Bingo?
If this scientific method of choosing numbers has not made it that far North, here's a short movie that might explain how this is accomplished.
»homepage.mac.com/rachelmeyrick/i···er2.html
--
Rich
»www.highgainantennas.com |
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lutful
Premium
join:2005-06-16
Ottawa, ON
·TekSavvy Solutions..
| I do not even accept bull $hit, so chicket $hit bingo is out of the question.
Richard, I was just curious to see if you guys used 5C or 10C rather than my calculated 8C. But it is not that important for the discussion so I withdraw the question for the sake of preserving the thread. |
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lutful
Premium
join:2005-06-16
Ottawa, ON
·TekSavvy Solutions..
| reply to public
Re: heating ideas for a cold winter
said by public :Thermoelectric battery is not so good in the summer because it produces a lot more heat than electricity. Wow. wikipedia says one gram of pollonium-210 generates 140W of heat for years! We will need 60% efficient TPV cells to harness RTH without melting lead enclosure.
said by public :A wind turbine would work if it does not ice up. WindSide compact vertical windmill is from Finland so I will assume it works well in winter over there. »Re: Battery and solar powered questions
But even low-end model cost $2K versus $500 for traditional windmills which are more efficient.
said by public :But overall you also need to consider the summer heat in a "permanent" installation. Yes. Back in 2004, we built a heavily-insulated enclosure that was heated in winter or cooled in summer by a Melcor TEC device. Cost was too high.
This winter, we are testing if frozen paraffin in sealed pouch will provide some insulation in winter.
They work very well to stabilize enclosure temperature in summer. Some details here:
»Re: Battery and solar powered questions |
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public
join:2002-01-19
Santa Clara, CA
·DSL EXTREME
| said by lutful :Wow. wikipedia says one gram of pollonium-210 generates 140W of heat for years! We will need 60% efficient TPV cells to harness RTH without melting lead enclosure. A full reactor will produce even more power from smaller quantity of fuel.
The basic Topaz reactor was about 1cubic ft not including the heatsink and produced about 40kW electric using a thermionic converter, and 25kg fuel. |
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