[Greenbuilding] differential thermostat controls for greenhouse

[Norbert Senf]

Differential controller:

http://www.thermomax.com/Solar_Controller_2005.php

temperature delta is adjustable from 4 to 24 degrees (F)

$139.00 including 2 sensors

it handles 75 w., for a larger fan you need to 
wire in a relay................Norbert

At 03:45 PM 9/25/2013 -0400, Topher wrote:
>On 9/25/2013 2:21 PM, Ross Elliott wrote:
>>Does anyone know of an off-the-shelf control 
>>system that would turn a ventilation fan on in 
>>a greenhouse and dump warm air into a high-mass 
>>heat storage room in winter / outside in 
>>summer? I want the fan to come on whenever the 
>>temperature in the soap-bubble greenhouse is 
>>warmer than the heat storage room, aka "the 
>>potting shed" (although since it's a Steve 
>>Kohrner flying concrete design it's more like a 
>>potting cathedral), so it’s not a fixed 
>>temperature sort of setup, it depends on the 
>>temperature difference between the two spaces.
>Most solar controllers are differential 
>based.  You could probably use one like that.
>
>Thank You Kindly,
>
>Corwyn / Topher
>
>--
>Topher Belknap
>Green Fret Consulting
>Kermit didn't know the half of it...
><http://www.GreenFret.com/>http://www.GreenFret.com/
><mailto:topher at greenfret.com>topher at greenfret.com
>
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-------------------------------------------
Norbert Senf---------- mheat(at)heatkit.com
Masonry Stove Builders
25 Brouse Rd.
RR 5, Shawville------- www.heatkit.com
Québec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092