This is my first winter in Colorado (Zone 5B) with a double walled polycarbonate greenhouse. My setup has a louvered intake and exhaust fans which I can automate on a cycle. I also have a high BTU natural gas heater. I’m trying to minimize the gas usage and I’m curious how much ventilation I actually need overnight in the greenhouse. I’m currently letting the temp drop down to 64 degrees. I run the ventilation fans for one minute out of every fifteen, 24/7. I’m growing orchids, hydroponic lettuce, tomatoes, peppers, and a variety of other flowers.
Can I decrease the frequency of ventilation overnight? I don’t have any humidity issues. I can also configure my fans to kick on if the VPD drops too low, which would protect from high humidity as well.
Greenhouse picts for interest.
by jvallery
2 Comments
What are you ~~growing~~ glowing in there?!
It’s a huge waste of energy to dump warm air out in the evenings during winter, and it’s not necessary to be honest. We have had mostly mild weather where I’m at in Colorado so far, but on the colder nights or cloudy days of winter(potentially down to -30F) I’m guessing you’ll have trouble maintaining temps if you run it at all