Originally Posted by Deezl
Thanks for the reply. I'm aware of humidity's inverse relationship with heat (which you explained nicely!) and I apply that indoors but I just can't quite visualize how it works in practice in a GH.
I have read other descriptions of the process you describe with the air being vented and heated at the same time but it seems like the dry air would just get vented out. Is there a limit on how fast it should vent or do the thermoset and humidistat settings complement each other? And what about when it's already warm in there (depped or otherwise) and it rains?
Maybe just let me know your fan size and thermostat and humidistat settings and I can visualize how they work together.
Ps I'm in Sonoma ca
I figured you had an idea of how rh works. You bring up a great point. It doesn't work well when it's hot and humid out. Works well for most of norcal with the Mediterranean climate dry summers. Here, it is always at least a little cool when it is raining. Parts of Sonoma close to the coast can be harder because of the warm moist air coming off the sea. You just need to crunch the numbers with your climate to figure out if it works for you. For every 20°f heat rise, RH is cut in half I think it is.
You want to put your heat on your intake side and your exhaust on the other so you aren't venting out to much warm dry air. Fancy greenhouse controllers have brains and they cycle venting and heating and just figure out out. My way takes some dialing in. I try to have at least 2 exhausts fans. One of them I really under size. For you, maybe a 10" shutter job dimmed down low would work, not sure. I hook that to my humidistat. That way I'm venting slow and not venting out all my warm dry air.
Other thing that really helps is directional air movement fans on loop. It keeps humidity low and even when your humidity isn't ideal, your plants and the molds& disease that can form won't know it. With enough air movement, higher humidity is acceptable. How it feels to you is a better gauge then any environment guage. Air movement makes higher humidity feel less muggy.