hey guys, I'm planning on building my first greenhouse. I live in florida and the temperature is low 90s and very very humid. What system could I use outdoors to create the optimum environment for my plants within the greenhouse?
Install an air conditioner.
Trust me, anything else will not be adequate. Been there... done that. Get a window AC unit and figure out how to make it work in your greenhouse.
I'm right next to you statewise and have very similar issues.
Even with AC, my grow area highs are in the lower 80's.
Agreed. An AC unit will help control temperatures, as well as reduce humidity. The AC unit I have keeps humidity around 50%, which is perfect for flower, but a little lower for Veg. But, you can still have a successful grow with low humidity in Veg.
If possible get a unit that has a built in heater as well, it would be a shame if a cold snap/front came in and killed your girls. A mild frost (temperatures of 31 – 32 degrees F. for an hour or two) or even temperatures down to 35 degrees F. will slow growth for several days or longer. A killing frost/snap freeze (temperatures below 31 degrees for more than two hours) can wipe out a crop.
I use an oil filled radiant heater in my grow area. It's small. I shove it in there when the temps get low... maybe for about 3 months in the winter.
You should setup your area to dissipate heat as effectively as possible. Heat will be your major issue... not so much the cold in Florida. If a random cold front does blow thru, you can easily stick a small heater in the greenhouse.
I really suspect your greenhouse would benefit from some sort of insulation layer. I have no idea how you could insulate a greenhouse and still maintain maximum light. When the outside air is 90, the sun will drive those greenhouse temps way high. You may want to do some pre-grow temperature testing.