[Greenbuilding] Looking for a whole-house fan thermostat

[Corwyn]

On Oct 04, 2007, at 15:51, Chris Hutchinson wrote:
> I've looked pretty hard and even the pricey t-stats I see that have an 
> outdoor sensor don't seem to have the ability to use the input as an 
> alternative set point. Here's what I would like my mythical thermostat 
> to do - namely, turn on when the outside temp is lower than either the 
> set point or the inside temp and turn off when the set point is 
> reached OR when the inside is the same as the outside. I could then 
> simply set the thermostat for, say 60 degrees and here's what would 
> happen (starting in the morning and cycling through to the following 
> morning):
>
> Out        In            Fan
> 55           60           off
> 58           62           on
> 62           62           off
> 80           64           off
> 85           66           off
> 75           68           off
> 68           70           on
> 60           65           on
> 55           63           on
>
> Does this make sense? I'm beginning to think that I'll have to get an 
> X10 controller, receiver, and 2 temp sensors to do this - yet it would 
> seem like something that someone should have made for people who want 
> to use outside evening air to cool the house instead of an air 
> conditioner! If we can't find one I've got dibs on the patent - this 
> could even be a plug into the wall unit that could do window fans or 
> stand fans.

If you were to combine a differential thermostat with a regular 
thermostat in series, you will get AND logic, and in parallel for OR 
logic.  Two simple thermostats are likely to be cheaper than 1 
complicated one.

Thank You Kindly,

Corwyn

-- 
Corwyn
Kermit didn't know the half of it...
http://www.greenfret.com/
corwyn at greenfret.com