Attic Grow Room

JAMES HOOKER

Well-Known Member
What is the best way to keep and attack grow room cool?My room gets about 98 degrees when my lights on 1000 watt.I bought a portable air conditioner but it doesn't get it cool enough looking temp around 82 degrees,room is about 8x10 x7 high.Think I can put and window air con. on the floor and just vent it out the back of the mylard?
Looking for and answer.Help!!!!:-(:-(:idea:
 

mike91sr

Well-Known Member
Not very experienced, currently working on cooling my 3x8x5 cab with 2-600w, but heres my 2 cents. I have a portable air conditioner and found 2 things. 1 it will never be as good as a window unit and 2 you need the unit right in front of an exhaust. Every foot of exhaust tubing you have in the room will increase temp through radiation. If youre going to put a window unit and stick the back out the side, make sure you have something to pull/push that hot air far away from the room. Just letting it vent out the back will still leave the hot air radiating back in. So put a huge box fan right behind it pushing away or something.
 

Xcon

Active Member
it will never be as good as a window unit.
I wondered why people use those things, they're very inefficient.

OP, If you use ducting to vent a window unit, it will still suck room air through the sides to vent out the heat. That's the problem with portable units, they have to suck already cooled room air through the unit to remove the heat that's absorbed by the coils. When you have an a/c in your window, it takes in outside air through the vents on the side of the unit to remove heat, making it more efficient. Once you start using cooled room air to vent the heat from the a/c, you lose efficiency.

edit: run an a/c on your floor and blow smoke at it to see where the air goes in and comes out
 

unity

Well-Known Member
I wondered why people use those things, they're very inefficient.

OP, If you use ducting to vent a window unit, it will still suck room air through the sides to vent out the heat. That's the problem with portable units, they have to suck already cooled room air through the unit to remove the heat that's absorbed by the coils. When you have an a/c in your window, it takes in outside air through the vents on the side of the unit to remove heat, making it more efficient. Once you start using cooled room air to vent the heat from the a/c, you lose efficiency.

edit: run an a/c on your floor and blow smoke at it to see where the air goes in and comes out
Cheers bro, don't mean to pick, but you are misinformed on the window units. There is no venting happening between the condenser section (outside coil) and the evaporator section (inside coil), the only air gap that you have would be a small hole (1"x1" about) that alows the condensation from the evaporator to drain back to the outside coil where it either drains down or as with most newer models gets evaporated by the condenser fan. I run a completley sealed room 12x8x6 with one 5000btu unit and it easily maintains 76f with ambient temps above 100 degrees around my grow room. Insulation is key! Sealing everything comes next, isolating the venting for the light etc.
Some window units have a ventilation option (air exchange).

Cheers Kind!



 

Mrfootball420

Well-Known Member
you can always try this route and modify a window unit to make it a portable. then you just get/make a stand for it. these cool way better then those portables do and you have major heat issues to deal with. its an option for you. credit goes to medicaljay from his grow journal. https://www.rollitup.org/grow-room-design-setup/419739-7000-budget-3000-watt-basement-6.html



You're going to need to remove the cover of the AC unit and cover the vents to it (I used some sheet metal I picked up at Lowe's for $10/each and a pack of nuts and bolts). The back exhausts the heat and the side and top vents are the intake. It's extremely efficient. I can drop my room down to 64 (lowest setting) with all my equipment running in a matter of minutes. You will need a booster fan for your exhaust. If you're going for a unit in the 12,000 btu and under range I'd recommend going with a 6" in-line fan for your exhaust. And of course, insulated ducting!! It'll also help reduce noise from your AC and exhaust fan.

You do have to worry about a window unit dripping condensation though. I have my AC unit on a wire shelf and it drips into a drain I have in my basement floor. If you don't have the luxury of a drain, a Bucket and a sump pump should do the trick just fine! At first I wish I got a portable, but after I finished this little project and compared stories with a friend that uses a portable, I'm glad I modified my AC unit. The cooling I'm getting from this setup is great! My AC unit doesn't work that hard at all. Another benefit to window units is they run like beasts. I used to live in California and they used to run all summer long for years without fail.
 

unity

Well-Known Member
you can always try this route and modify a window unit to make it a portable. then you just get/make a stand for it. these cool way better then those portables do and you have major heat issues to deal with. its an option for you. credit goes to medicaljay from his grow journal. https://www.rollitup.org/grow-room-design-setup/419739-7000-budget-3000-watt-basement-6.html



You're going to need to remove the cover of the AC unit and cover the vents to it (I used some sheet metal I picked up at Lowe's for $10/each and a pack of nuts and bolts). The back exhausts the heat and the side and top vents are the intake. It's extremely efficient. I can drop my room down to 64 (lowest setting) with all my equipment running in a matter of minutes. You will need a booster fan for your exhaust. If you're going for a unit in the 12,000 btu and under range I'd recommend going with a 6" in-line fan for your exhaust. And of course, insulated ducting!! It'll also help reduce noise from your AC and exhaust fan.

You do have to worry about a window unit dripping condensation though. I have my AC unit on a wire shelf and it drips into a drain I have in my basement floor. If you don't have the luxury of a drain, a Bucket and a sump pump should do the trick just fine! At first I wish I got a portable, but after I finished this little project and compared stories with a friend that uses a portable, I'm glad I modified my AC unit. The cooling I'm getting from this setup is great! My AC unit doesn't work that hard at all. Another benefit to window units is they run like beasts. I used to live in California and they used to run all summer long for years without fail.
I love it when people get inovative!!! :)
The booster fan is what makes this work. Nice Job!
Kind
 

Mrfootball420

Well-Known Member
yeah its pretty sick, i get amazed at some of the shit i see around here sometimes. he inspired me to go this route, and yeah the booster fan is a must. summer time is just about over and a/c units are going to be on sale soon :)
 

Xcon

Active Member
Cheers bro, don't mean to pick, but you are misinformed on the window units. There is no venting happening between the condenser section (outside coil) and the evaporator section (inside coil), the only air gap that you have would be a small hole (1"x1" about) that alows the condensation from the evaporator to drain back to the outside coil where it either drains down or as with most newer models gets evaporated by the condenser fan. I run a completley sealed room 12x8x6 with one 5000btu unit and it easily maintains 76f with ambient temps above 100 degrees around my grow room. Insulation is key! Sealing everything comes next, isolating the venting for the light etc.
Some window units have a ventilation option (air exchange).

Cheers Kind!
That's exactly what I was saying however, if you run a window unit on the floor, it WILL use room air to cool the coils, even if you vent the hot air coming out the back. It's like putting your window unit up against a hole, with the entire unit inside, it will run less efficiently because the intake for the condenser is located on the sides of the unit. When it's in a window, those vents are located outside the room.

He would have to run seperate vents for intake and outtake if he were using a window unit on the floor.
 

donutpunched

Active Member
All it depends were you live and how the attic is set up.. Here is one that has vaulted ceilings... Running 3 600w cool tubes... the ceiling is about 5.5 feet at the highest point.. Since it is set up in an area that stays pretty cool and usually does not get above 85. There are 2 fans one mounted inside the attic where the air vent is... the other is mounted outside where the opposite air vent is. One (exhaust side) is set to come on at 75 degrees the other at 80 degrees.... The cool tubes are cooled from inside air and the hot air is dumped right at the exhausting fan.... this is for sure NOT a sealed room.... But you can scrog with these heights.... Little hard to move around but the ladies are very happy... The entire inside as been covered with insulation board otherwise it would get way too hot....I tried it and it did not work during the summer... But with the insulation board it worked very well attached is a pic I hope it helps.. Donutattic.jpg
 
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