How do you cool down your greenhouse on hot days?

Box fan

Buy a portable ac unit

Green house or tent

Use foger

I am looking into shade cloth but I haven’t tried it yet

i designed our systems for hot and cold weather. so as long as yoursystems are properlt done you dont need any cooling on it

Shade cloth and auto vents

Fogger or swamp cooler/wet wall. And shade cloth.

Thanks for the big amount of recommendations :) this will cool down as much as i need. The wet wall is amazing, especially when you have water (like lakes, rivers etc.) around you!

combination of all the above

solar fan, Or hot air rises , input low output high

mine gets to 160 in the summer. I use it as a dehydrator..lol…. I dry my garden stuff in it....

Shade cloth

I have a sunshade on the west side, an oscillating fan and I mist water for an hour or two each day during the heat of the day.

Heat pump

Water. Basic science as evaporation absorbs energy.

Shade net and sprinklers

I’d throw money at it if I could, but alas. Shadecloth over is all I have. Some is even in full sun. We’re in the middle of summer here and have had temperatures up to 45C (114f) so far no plant losses.

The heat problem is primarily in water temp, above 23 degrees C root rot from anaerobic bacteria can set in if not enough oxygen in the water.

Dennis, when temps are hot, like that,,,, you will at the very least insure super good air flow. Run Fans if you can! There's no guarantee, but this will definitely help. Some edibles are simply not going to endure temps above 90F and definitley not 115F. Choose edibles/varieites that may be best suited for warm/hot conditions, then of course switch back when temps drop.

Move air in and out.