X10 Community Forum

🔌General Home Automation => Automating Your House => Topic started by: ggrote on September 11, 2009, 11:27:21 PM

Title: Automatic garage ventilation
Post by: ggrote on September 11, 2009, 11:27:21 PM
I'd like to design and install venting systems for my garages.  In the summer, when the temperature is lower outside than inside, I'd like to bring outside air in.  Similarly, in the winter, when it's warmer outside than inside I'd like to use the outside air to warm up the garage.  So in my mind I need inside and outside temperature sensors, a controlled vent fan, and a louvred intake, plus a simple logic-based controller.  I can envision doing it without X-10, but thought I'd see what you guys thought about using X-10 stuff for it.  Thanks.  ;D
Title: Re: Automatic garage ventilation
Post by: JeffVolp on September 12, 2009, 09:23:57 AM
I'm actually doing the summer half of what you describe.  I added a vent vent fan with a cover, and built a servo to close the cover when the fan turns off.  There is enough leakage around the three garage doors that I did not have to install an intake vent.

Then I installed thermistors inside and outside the garage, which are read by the Ocelot through a SECU16.  The algorithm to convert the voltage reading from the thermistors to degrees Fahrenheit is described on the ADI forum.

I use the previous high and nighttime low to determine whether the vent fan should be turned on.  It turns on in the early morning when the temperature is near the low, and runs until mid-morning or until the outside temperature is almost back up to the garage temperature.

This and insulating the metal garage doors has made a significant difference in the summer garage temperature.

Jeff
Title: Re: Automatic garage ventilation
Post by: ggrote on September 15, 2009, 02:18:25 PM
Thanks, Jeff ... I'll give that info a look ... I've not used the Ocelot or SECU16, so I've got some reading to do (yeah, I know ... noob ...  ::)).

I was thinking of having the fan running when (using simple basic notation):

     [Month = Jun thru Sep] AND [garage temp > 70°F] AND [inside temp - outside temp > 5°F]

     OR

     [Month = Dec thru Mar] AND [garage temp < 50°F] AND [outside temp - inside temp > 5°F]

But I assumed that I would be tweaking those relations during the first year the system was in place.

Your point is taken about leakage around the doors ... as long as I install the fan in the ceiling at the front of the garage (i.e., farthest away from the doors) I should get decent flow through the entire space.