Cooling a greenhouse....

In nor cal...we get summers that reach up to 110*. In a greenhouse, it would be 120* on one of those days.

Im wondering if a 24000 btu wall mounted air conditionet will be enough to cool down a 10 x 24ft sealed greenhouse from 120* down to atleast about 90 (80 would be better...lol).

Ill also be running about 6 oscillating fans & a 6" exhaust outake fan.....thoughts?

Continuosly run exaust throughout day?
Or let it run on timer multiple times a day, allowing the gold air to build up instead of just sucking it out?

yes, 24k will reduce temps, at a considerable cost. I use a 80% shade cloth to accomplish the same thing for little bucks

Lacedwitgame said:

In nor cal...we get summers that reach up to 110*. In a greenhouse, it would be 120* on one of those days.

Im wondering if a 24000 btu wall mounted air conditionet will be enough to cool down a 10 x 24ft sealed greenhouse from 120* down to atleast about 90 (80 would be better...lol).

Ill also be running about 6 oscillating fans & a 6" exhaust outake fan.....thoughts?

Continuosly run exaust throughout day?
Or let it run on timer multiple times a day, allowing the gold air to build up instead of just sucking it out?

Click to expand...

Peak venting - bet you have a plastic loop greenhouse eh? See the link below.
louvered exhaust fan of about 4' dia. that's ft of dia....see the link below.

Fans, vents and anything greenhouse - greenhouse supply - www.farmtek.com

You don't have the ability to roll back the covering then eh? Up from the ground on both sides?
Not good..

Plexi glass..oldschool type. Sealed, im going to have to rely on hvac..

12x10 harbor freight greenhouse, but i got 2 of them together making a 10 x 24

B

chemphlegm said:

yes, 24k will reduce temps, at a considerable cost. I use a 80% shade cloth to accomplish the same thing for little bucks

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I thought of this but figured shade would be counterproductive?

I would frame up and install the biggest intake shutter and exhaust fan you can find. Get them on a thermostat so they work automatically. The shade cloth idea is a great one. You'll be surprised. I do think the AC idea is going to be steep $$ wise. How about just move them outside with some circulation fans or even some shade cloth covering them. Finish them in the greenhouse in the fall

Lacedwitgame said:

B

I thought of this but figured shade would be counterproductive?

Click to expand...

I thought the same of shaded sun....until i used it. Lux meter shows me indoor hid's are shade compared

Whats a commercial greenhouse running... maybe 75f/80f, 60/70%rh and a 0.3/0.5m-s-1 air speed at top end... Somewhere around there you start hitting correct vapour pressure deficits etc etc.

Dr Magill said:

I would frame up and install the biggest intake shutter and exhaust fan you can find. Get them on a thermostat so they work automatically. The shade cloth idea is a great one. You'll be surprised. I do think the AC idea is going to be steep $$ wise. How about just move them outside with some circulation fans or even some shade cloth covering them. Finish them in the greenhouse in the fall

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Im shooting for year round growing. The greenhouse will be flower only with a seperate indoor veg room.

I have been thinking of going year round with a green house. I have a south facing hill I though about cutting into. Only the front and top would be glass. Maybe lay a couple hundred feet of 8 or 10 inch pipe in the ground and circulate air through it to warm in the winter and cool in the summer.

Lacedwitgame said:

Im shooting for year round growing. The greenhouse will be flower only with a seperate indoor veg room.

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Yes. I realize that. Use your local climate to save on power costs. Year round can be a few different styles

A big evaporation cooler like they use in home depot would be way cheaper than ac. they make big fans that run on solar, I saw one at norcal hydro in redding they had put misters on it and it really put out a lot of cool air.

^ alot of cool air, and RH? in summer I seen 130 f, plants didnt seem to mind the short duration of high heat there. my greenhouse rains in the winter, no good for my girls. heating the greenhouse in the winter
costs me 800 dollars per month, electricity, coal. I dont use the greenhouse for that anymore.

Lacedwitgame said:

Plexi glass..oldschool type. Sealed, im going to have to rely on hvac..

Click to expand...

I wouldn't! I wouldn't even try.....It's not going to be practical at all!

You can get things that fit - or make them fit! Sure as hell not hard to make some venting.

The only way that thing is Plexi, is if you swapped out the "cardboard" style plastic sheets.....that would cost a fortune!

Shit, a good storm will blow that thing around as far as the plastic panels. In winter months, if your in more northern climates. The heating will be a bitch. The green house's I ran (commercial flower ones) were heated by underground steam pipe's. I built a cpl of the smaller commercial loop and plastic ones for starting muck farm and cabbage family crops that we farm. I heat that the same way with a wood boiler....

Your being told by some folks that know. Believe us - Find another solution!

You can make a pretty fine DIY greenhouse from old trampoline halves and pipe's. The right plastic and a plastic welder....Always able to repair for cheap.....

Already got em...we know what to expect as far as shortcommings from the greenhouse. Were just going to have to adjust....

Lacedwitgame said:

Already got em...we know what to expect as far as shortcommings from the greenhouse. Were just going to have to adjust....

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Good luck then sir!

chemphlegm said:

^ alot of cool air, and RH? in summer I seen 130 f, plants didnt seem to mind the short duration of high heat there. my greenhouse rains in the winter, no good for my girls. heating the greenhouse in the winter
costs me 800 dollars per month, electricity, coal. I dont use the greenhouse for that anymore.

Click to expand...

RH here in the summer is really low 20-30%, i use ec to cool my house and the Rh stays about 50%

I'd try to keep shade cloth at 30%, bud density can be an issue if you go too heavy. I'd probably try to cut some large holes in it or even cut side walls off and hinge them. Good airflow is the key.

backtracker said:

RH here in the summer is really low 20-30%, i use ec to cool my house and the Rh stays about 50%

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yeah my greenhouse RH is significantly higher than the rh outdoors without any controls. Add a dirt floor, a plastic sheet and some watered plants to air blowing through a wet sponge....I suspect the rh then would be so high/ risky for cannabis flowers to flourish healthy