[CrushnYuba]

Devoted 1: here's some pictures I posted in another thread on auto dep: I will do a more detailed build out step by step when I build the next auto system.

[who dat is]

Can you go into some more detail regarding the last two pictures you posted please?

[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

Thanks again!

[Deezl]

My GH is 20x24 w 6' sidewalls w plywood ends and manual internal dep.
I built it last year but just used a combo of leaving the sides up and tucking inline fans under the sides, worked ok but I wanna get fan/heat/dehu/whatnot this year.

[CrushnYuba]

Whodatis: those are the motors and arms close up for cheap auto dep. Can automate your tarping for less then 1k. Here's a further out picture. It's all strapped down for the winter so I can't show you how it works in action, but check out utube for karmens greenhouses and emerald kingdom. They use same system.

[who dat is]

Originally Posted by CrushnYuba

Whodatis: those are the motors and arms close up for cheap auto dep. Can automate your tarping for less then 1k. Here's a further out picture. It's all strapped down for the winter so I can't show you how it works in action, but check out utube for karmens greenhouses and emerald kingdom. They use same system.
View Image

Thanks for the reply

With this system do you get light leaks at the endwalls?

[CrushnYuba]

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

Thanks again!

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.

[CrushnYuba]

Whodatis: if you do it right you shouldn't have light leaks. The end walls stay blacked out. You gotta put strips of panda film like a foot wide around the edges of the endwall so you get good overlap. It's like how people protect their greenhouse against air leaks when they do roll up sides just for light. You can use batten tape to keep everything tight if you are in a windy location just like roll up sides to.

[Deezl]

Thanks! That's interesting about the smaller fan.
So in the setup you describe, the big fan kicks in when it gets too hot and exchanges all of the air out quickly. The small fan and the heater/stove kick on when it's too humid and they exchange the air out more slowly.
And in Northern California it's usually cool enough that the heater/stove can heat up the air enough to dry it without heating it up enough to trigger the big exhaust.
(?)
And when its a hot enough day to trigger the big fan then it's usually dry enough not to worry about the humidity.
(?)

Thanks again

[CrushnYuba]

Deezle: you got it on all counts mang! It works for most places in norcal as long as your not right by the ocean.

Don't get to crazy undersizing the small fan. Maybe a 12. Definitely no bigger then 16. It's for air exchange. Not really cooling.