Need help choosing an air conditioning unit

P

POTNU

Member
Please can someone help me with this, where i live it can get pretty hot and humid(up to 92f with lights on and 80-90rh) so i am looking for a unit do cool and remove this humidity from my flower cabinet, the size of the space is 2.5x1.5x5.5ft.
i was thinking a simple small used 7000btu window unit, can find those in good condition really cheap around here and rig in a loop only for the flower space
but them it came to mind that those units do not have inverter compressors and now i am afraid that due to the small space it would turn on and off the compressor too much making it cost too much in the electricity bill
another option would be to buy a new one of the same cooling capacity but with inverter technology, that would cost me 8x more, since it would have to be a new one brought from store.
what would you guys do? would the small space make de simple air unit keep turning on and off so much that it would cost too much to run it?

ps. where i live weed for self consumption is not legal but not a crime also, would be a the equivalent of a minor offence, with at most some communitary work as penalty, but id like to avoid headaches, thats the reason behind the window unit, and why i cant just put a cheaper inverter split unit there
 
Last edited:
W

watsongreenthumb

Active Member
your going to have a really hard time getting an air conditioner to effectively cool a space that small. an a/c with an inverter compressor would in theory work better for sure but even then its just such a small space that I think its going to have a hard time. not to mention the ac would take up most of that space. If possible I think using an inline fan with a carbon filter to take out any smells will work alot better, as long as this cabinet is inside where the air is cooler. If the room the cabinet is in is hot you could install an air conditioner in that room and then run that cooler air through your cabinet. I can help better if you give me a better idea of the setup
 
P

POTNU

Member
watsongreenthumb said:
your going to have a really hard time getting an air conditioner to effectively cool a space that small. an a/c with an inverter compressor would in theory work better for sure but even then its just such a small space that I think its going to have a hard time. not to mention the ac would take up most of that space. If possible I think using an inline fan with a carbon filter to take out any smells will work alot better, as long as this cabinet is inside where the air is cooler. If the room the cabinet is in is hot you could install an air conditioner in that room and then run that cooler air through your cabinet. I can help better if you give me a better idea of the setup
Click to expand...
Thanks for the reply mate, the ac is wold be in a window right next to the cabinet, already have a fan with close to 200m² for exhaust and was gone to put a carbon filter to it
the temperatures here are 87,8(day) 86(night) on the hottest summer days and 82,4(day) 80,6(night) on winter, not counting the heat from lights
also the hm is quite high
thinking about extending the cooling to the veg spaces so it balances a little bit more, but maybe them the hm there will be too low?
rn temps in veg are only 1ºc above ambient with light on on 50w, lights are on during the night now, with the ac would turn it on during the day, 2-3ºc hotter but energy is a lot cheaper
going keep 1 mother plant only in each space for clones
on flower there is 250w, maybe overkill lol, thinking of reducing to 200 or 150, but even so temp surely is going to be too high for flower
flower is setup for ebb e flow on hydroton, gona put bunch of small clones there for sog, only aiming for the main colas
attaching pics of the entire setup now
 

Attachments

Last edited:
Oldreefer

Oldreefer

Well-Known Member
I run a 7000 btu window unit in an adjacent area to my grow area...it also has a dehumidifier side to the ac so it's more efficient at various times.
Previously ran a 7000 btu portable that also had a dehumidifier op too that did a good job...
Controlling a small space is more problem than a little bit larger area....
 
P

POTNU

Member
Oldreefer said:
I run a 7000 btu window unit in an adjacent area to my grow area...it also has a dehumidifier side to the ac so it's more efficient at various times.
Previously ran a 7000 btu portable that also had a dehumidifier op too that did a good job...
Controlling a small space is more problem than a little bit larger area....
Click to expand...
but you did cool the whole room right?
thats what i am going do i guess
can anyone tell me if i run the ac only during lights on it would harm the plants too much? if temps go from 78,8 with lights from 82-84 lights off
the rm would rise during lights off ofc, but i am going to put ac filters on the passive intake to avoid mold spores from getting in
 
Oldreefer

Oldreefer

Well-Known Member
Yes, I actually control climate in the whole area...about 350-400 sq ft... for less swings in temp and hum.....with a perpetual grow going for 20 yrs, I have definitely seen what can and will change an end result and the route getting there. Control temps and all else will fall in line...mostly.
 
Lenin1917

Lenin1917

Well-Known Member
Might want to try and increase you’re air intake/exhaust on the cabinet too. I run a 15kbtu window ac and just keep the room a few degrees cooler than the I want the tent. With 1000w open hood hps I had to keep it at 73f for a tent temp of 80-83f. Led the temp difference is enough that I’m gonna need to run the heater this winter.
 
P

POTNU

Member
Lenin1917 said:
Might want to try and increase you’re air intake/exhaust on the cabinet too. I run a 15kbtu window ac and just keep the room a few degrees cooler than the I want the tent. With 1000w open hood hps I had to keep it at 73f for a tent temp of 80-83f. Led the temp difference is enough that I’m gonna need to run the heater this winter.
Click to expand...
do not think increasing exhaust would do me much good, with the fan i already have the entire air can be vented 1,5 times each min already, it can move 100m²/h and the intake was rigged to pull from the outside to make sure it comes as cool as possible.
 
Last edited:
W

watsongreenthumb

Active Member
yes running the ac in the window would be perfect, like others have mentioned there will be some difference between temps in the room vs temps in the cabinet but as long as the room is fairly cool and your moving a good bit of air through the cabinet (and it seems like you are) I think you will be just fine. oh just read your last post- once you get an air conditioner in the room, you will want to pull your air from the room, NOT outside. also exhaust your air into the room as well, and the ac will deal with the heat and humidity. if you exhaust your air outside you will be pulling all your airconditioned air outside and make the airconditioner work much harder/ basically wasting that cold air. I am assuming you live in this house, so your co2 levels inside are going to be higher than ambient, and your plants will benefit from that as well.
 
P

POTNU

Member
ok, got a 10.000 btu ac to cool the entire room, thanks everyone for the reply
now i'm making myself a carbon filter, store brought ones are expensive where i live, for what i looked already i cold make one for less than 1/5 the price, not sure if i should use pellets or grain activate coal, i could get access to grain that 1mm to 4mm mixed or 5mm pellets(for what i gatter most comercial filters use a 2" layer of charcoal so that's what i am going with), what would do better?
if the grain restrict the airflow too much but filter better i could add another 100cfm fan and would still be way cheaper, any ideas?
 
Three Berries

Three Berries

Well-Known Member
You could open the AC up and bypass some of the air so it does not go across the evaporator or block it off, effectively making it smaller.
 
Three Berries

Three Berries

Well-Known Member
xtsho said:
Seriously?
Click to expand...
Yes or even block off the front with a sheet filter. Anything to slow the air flow across the coil. It won't be as cheap as getting a smaller one as it will cause a higher load. Don't know what kind of thermostatic control it you have..
 
Three Berries

Three Berries

Well-Known Member
POTNU said:
wouldn't that make the compressor just work more to reach the desired temperature?
Click to expand...
It would slow it down. Depends on the load. But reducing the condenser or evaporator effectively reduces the entire btu handling of the system., aka smaller. It would cut down on the cycling assuming it was big enough to cycle off. Ideally you would want to limit flow though both. But the work is done at the evaporator as far as cooling.

It's like the AC freezing up in your car.
 
Last edited:
P

POTNU

Member
Three Berries said:
It would slow it down. Depends on the load. But reducing the condenser or evaporator effectively reduces the entire btu handling of the system., aka smaller. It would cut down on the cycling assuming it was big enough to cycle off. Ideally you would want to limit flow though both. But the work is done at the evaporator as far as cooling.

It's like the AC freezing up in your car.
Click to expand...
i get now, what about the risk of freezing the condenser?
i am asking just out of curiosity anyway, already got the ac for the whole room, was planing already on growing some cubes anyway
 
Three Berries

Three Berries

Well-Known Member
POTNU said:
i get now, what about the risk of freezing the condenser?
i am asking just out of curiosity anyway, already got the ac for the whole room, was planing already on growing some cubes anyway
Click to expand...
If it freezes it should shut off the compressor until it thaws. My dehumidifier does but keeps blowing air. When it's thawed the compressor comes back on.
 
You must log in or register to reply here.
Top