a/c in the winter

We are growing in a basement where outside air can not be brought in.

We want to get a 5 ton ac to cool our 8000w bloom room. We are currently air cool the lights but want to take that out too.

What do other growers do during the winter when trying to have a sealed ac cooled room?

That what I do I'm currently running a 4000 watt room and have two portable ac units runnin a 8,000 and 12,000 btu I'm on my last week and there lookin a1

Are you in a legal state? If so id try to invest the money to pull air in from the outside. Maybe cut into the floor or something like that if possible. Cant beat the free cooling of the winter air. And it saves you on co2

5000k air cooled 3 13000 btu portable ac units, i am in texas and i run the lights at night to help keep it cool and my room does get over 74 in summer when it was 106 and it is sitting at 70

but if you have the space i would definetly put a 5 ton unit in there, money no problem? get the 5 ton unit when i did a ware house thats what i did for 9 lights during day not air cooled no problem

The issue is using the 5ton during the winter.

The one we are currently using is a 24k btu ductless split unit. It worked great in the summer but in the winter it froze up.

I hear there are adapters or other attachments that can be installed or purchased when installing the unit.

5ton shouldnt waste any co2 because we are recirculating the air and have a co2 generator connected to a co2 monitor.

We don't want to air cool any more

We also want to cool the two 1000w lights in the veg room next to it. It is essentially 2 14x11 rooms sharing a wall.

Outside air is the only solution that I can think of lol.

You need an ac that works in LOW AMBIENT (cold) conditions most quality
Japanese inverter mini splits can operate at low ambient temps. Hydroponic specific models are usually a scam. I run a mitsubichi it would cool with 3 feet of snow on the ground.
Applications such as computer server rooms require this as well. I believe when ordering a new
ac (full size split system) from a reputable manufacturer- carrier, train. lennox etc... low ambient can be specified for a little more cash. I believe these will work by varying the condenser fan speed though
since inverter models have not become main stream in the full size residential ac market yet.

There is also a universal wire in kit for cheap mini splits that will provide low ambient
operation by varying condenser fan speed. I believe they are about 250 dollars. Depends on how cold your running out side though
Lg units have a kit for there non inverter models but recommend a wind baffle as well so winds wont over cool the condenser.

budbro18 said:

Are you in a legal state? If so id try to invest the money to pull air in from the outside. Maybe cut into the floor or something like that if possible. Cant beat the free cooling of the winter air. And it saves you on co2

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It seems whenever you try cooling so much heat with a massive temp difference you end up with too much humidity. Sometimes pooling of water. Possibly there's some setup with an air to air heat ex-changer that would help I dunno.

If your planning on 5 tons of ac are you planning on getting a central ac? I believe I read somewhere that the are all made by design to operate at very low temps, unlike some mini-splits.

I agree but during the winter its dry as can be so ive found it that i have about no condensation on my ducts and other things. During the summer if i dont take care properly theyll be dripping which is never good. But winter, for me and most people who have real winters, Id almost like some extra humidity haha.

budbro18 said:

I agree but during the winter its dry as can be so ive found it that i have about no condensation on my ducts and other things. During the summer if i dont take care properly theyll be dripping which is never good. But winter, for me and most people who have real winters, Id almost like some extra humidity haha.

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I know enough just enough about relative humidity to make me dangerous. Never had a problem in summer but had many in winter especially in sub zero temps, water has flooded my ducting. I've tried insulating my ducting and ended up with pooling in my hoods.
Also, trying to balance temps indoors when winter temps change drastically has been a nightmare. Even with temperature controlled switches and variacs.

Don't get me wrong I'm not against using nature to cool, I just have never nailed it down.

Maybe you could describe your setup and avg winter temps?

I have all my windows wrapped in b&w poly, 6mil. And before i do this i make sure to crack one of the windows. Only about 1/2" so its not noticeable from the outside that a window is open all winter. haha.

Then after i wrap the windows i cut an intake hole slightly smaller than the 6 inch ducting so when i force it in it would be light tight and pretty air tight. Occasionally id throw some gorilla tape on it if it stretched more than i wanted.

Connect about a 5 foot piece to it a 6 inch booster fan.

Id place that on top of my 4x4 tent. I grow in a 9x12 room with grow tents of varying sizes. My 4x4 is furthest away from the door and it blows the cool air over the top towards the wall the door is on.

Thats just about it. Oh! also i run my lights so that somethings always running. So its constantly keeping it warm. My 400 cmh runs for 18/6 and about 2 hours before that shuts off my 12/12 600w hps kicks on and its all in sync so i have about a 6 hour window to view all my shit on at once. haha.

It might help that im not drawing directly from the outside into my hood/hot tent and maybe since its cooling the air outside the tent that its taking in it might be lowering the temp difference on the ducting vs tent temps.

My temps would stay around 72 in the room when everything was on. So in the tents they were around 75. My veg and clones ran during the day and my flow would kick on as it got dark because it always gets colder then.

Ive been wanting to add a backdraft damper and one of those thermostats connected to the plugs for the fan pulling in but ive never had a temp below 68 or above 80 so i havent been convinced to. The temp wouldnt fluctuate as much but im within 8-10 degrees of change from one day to another depending on whether its extra cold out or not too cold out.


Its kinda like what i used to do for summer compared to what i do now for summer. I used to have my ducts for my tents connected to the a/c output so it would blow right in the tent to keep it cool. And now i just cool the whole room to a degree or 2 colder than what i would pump right into the tents and i have almost no condensation on my ducts.

Edit: My average winter temps are 25/34 (avg min/max) some days colder some days warmer. Rarely warmer.