Cooling a greenhouse....

Lacedwitgame

Well-Known Member
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?
 

Dr. Who

Well-Known Member
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?
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..
 

Dr Magill

Well-Known Member
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
 

Kingrow1

Well-Known Member
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.
 

Lacedwitgame

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

whitebb2727

Well-Known Member
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.
 

backtracker

Well-Known Member
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.
 

chemphlegm

Well-Known Member
^ 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.
 

Dr. Who

Well-Known Member
Plexi glass..oldschool type. Sealed, im going to have to rely on hvac..
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.....
 
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Lacedwitgame

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

backtracker

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

Bugeye

Well-Known Member
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.
 

chemphlegm

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

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
 
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