[Kinosabe777]

Hey guys I built a a 20x30 hoophouse and was ready to put my babies in there until another grower warned me not to because of how hot it is going to be in there this summer. I live in Northern California where it could get up to 100 degrees. The only thing I have to defend against the weather are two industrial fans I bought . Any thoughts?

[Limeygreen]

The biggest thing in a empty greenhouse being empty will be low humidity with high temperature. You may consider buying some shade cloth or slats of wood to put over the glazing to cut down on light to reduce heat when leaf area is too little to try and make a more comfortable greenhouse, 50-70% should do, better if you had both so you can go with smaller plants with 50 % then as they get bigger use the 70 % until you can get the shade completely off. I am Celsius, 40 would be too much, 28 would be great if you can get it although I have grown tomatoes, peppers and leafy greens in 40 degrees with no issues with side ventilation (passive) with no issues by pounding water to them, usually 6 litres per plant per day up to 8, broken up into 3-4 rounds about 3 hours apart. Good luck.

[stone meadow]

open ends and sidewalls, mount your fans up high and do what you gotta do
ive had highs of 117 and a low of 36 already this year.
its amazing how that 117 inside the gh doesn't seem like 117 would outside.
I find it fun how when doing an indoor if it gets less than 60 or more than 80 alarms start going off. now I just tell myself to stay calm and remember what the temps will be in 6 months in the gh

[Jahcr1]

Over 34 centegrades the resin prduction is damn low... plagues usually attacks and metabolism go super slow.. put some fans to solve this

[farmerlion]

Kinosabe777, mine has been 100 to 110 a couple days. I had good ventilation with fans and one side up about a foot. It was only 10 degrees hotter inside than outside. I misted the plants as often as I was around to do so. In the end they are fine and doing well. It's a lot hotter in Africa and Mexico where my genetics are from than in North Dakota. I told my plants suck it up ladies, your not getting A/C. Peace

[OldPhart]

Put something like the below swamp cooler in one end, and put an exhaust vent high on the other end... problem solved. I've seen greenhouses in areas where the temp may be over 100F for two months straight; they use swamp coolers and never have any issues. The plants actually love the humidity/heat combo. I know they make swamp coolers specifically for green house use, but I can't seem to find a link to one; although I didn't look too hard.

https://www.amazon.com/Portacool-PAC.../dp/B000Z5CVPW

[coldcanna]

Like they said as long as you keep the humidity jacked way up the plants do great in the high temps, after all this plant is from the equator

[Jack T.Ripper]

Does your GH have roll-up sides? What about a temp-activated window opener?

[ChaosCatalunya]

Aso thers said, high humidity ,swamp coolers that blow over cold water

They sell a product here in Spain that makes a thin wall of water like a door at the entrances, cools greenhouses down no end

[hooddro]

You can be at 120 for several hours and if your plants have water they will grow like a motherfucker.