Greenhouse vents and ventilation.
Here are many examples of greenhouse vents and how they work.
I hope one of these can solve your ventilation problem.
If you live in a mild west coast area, little frost, cool summers, then a passive vent made out of shade cloth might be enough.
Then we found these solar vents. (The little ones on the left.) which led to the one on the right.
We even tried a turbine vent, but with our heat, forget it!
We tried being cheap and using a small wax windo opener, the wind ripped it off and it wouldn't open much.
Here are more of the first vents we tried. They work ok for small greenhouses.
Then we started getting serious.
One of the greenhouse end walls with vents open. This solved most of our ventilation problems. That and keeping the greenhouse to 50 ft. instead of 100. Discovering you only have to carry plants 25 ft instead of 50 ft. also helped.
Top vent of a polycarbonate greenhouse at an air temperature of about 90F.
The higher you can get the 'out' vent the better it will work, unless you have regular wind, then it needs to go high on the leeward end.
The vent structure from inside the greenhouse.
Poly greenhouses are a little trickier, you have to frame the vents.
The end of a small polyethylene greenhouse at about 90F.
Last edited on 2012-12-31 08:22:36.