Greenhouse: Harbor Freight Automatic Vent Opener, 2 by Ric_of_MAF

Ric_of_MAF wrote:
I found the same problem with my Bayliss openers. I also thought they were slow to close at sundown. Currently I just adjust the heat by opening the door a little. A thermostat controlled fan mounted in the highest part of the end wall is more reliable. The fan does not need to be large for early/end of season removal of excess heat. I am going to mount a dryer vent (4") in one end, with a 4" computer fan, I also purchased a thermo switch at Ace hardware for less than $20. Set at 80-85*F, I can absorb some of the excess heat in the GH before venting the rest.
I later plan to install a inward 10" shuttered fan with a poly tube for circulation and cooling, left running it circulates air and the shutters are on a thermo switch and open for inducting cool air. This can also be set high enough to retain some of the excess daytime heat.

I also use the indoor/outdoor thermometer to watch temps from in side the house.

This message was edited Dec 15, 2013 11:14 AM