Mini split Questions?

I have a 8.7 inch ceiling and 4 x 15 foot grow space I’m going to dedicate to my medical grow. I have a plant count and don’t anticipate any lighting over 2,000 watts.

I know I should have ruffly 5,000 btu per light but I just want to be sure before purchasing.....


1.) 1 ton or 2 ton mini split?

Will be insulated and sealed to the best of my ability.

I will be splitting the room, 4 x 10 for flower and 4 x 5 for veg/prep.

Don’t know what I’m going to do for drying room...

2.) Plan on installing some sort of fan to cycle air from mini split room aka flower room, into veg room....or am I dreaming this will work?

This is in a garage with summer outside temps that reach 100 degrees in the spring and summer.

The reason I ask is I see 5-5500 btu per 1k light but idk if I’m supposed to add the size of room to that. My room size calculation brings me to about 8,000 btu without lights. So if I need that plus another 10k or so for 2k worth of lights I’m looking at a two ton, if it’s based off just lights I’m going with 1 ton.

Big price difference.


Could use some help.

I don’t know the setup or design of the garage, but in theory it should work. You’re going to want to be circulating the air, and fans between the rooms will help in cycling. Are you going to punch out the garage for an intake/exhaust? With your high temperatures air conditioning might be needed for those hot months.

Is your flower room going to be perpetual? as in, flowering plants of all different ages in the same room? Harvesting each plant as its ready?

Or split that flower area in two and stagger harvests every 4-5 weeks...
might be easier coughing up enough clones for the perpetual setup.

I would add the light btu to the room btu, especially since its a garage, and go 2 ton.

XipXipXoom said:

Is your flower room going to be perpetual? as in, flowering plants of all different ages in the same room? Harvesting each plant as its ready?

Or split that flower area in two and stagger harvests every 4-5 weeks...
might be easier coughing up enough clones for the perpetual setup.

I would add the light btu to the room btu, especially since its a garage, and go 2 ton.

Click to expand...

All age plants in flower room. Trying to figure something out for hang drying my ladies once ready....

I was thinking I need the 24k myself, just want to be sure it’s needed before I drop some change on it.

Thanks, for the reply.

Are you putting the mini split in the grow room or are you doing the whole garage? If you are worried about heat why not go LED. You’ll probably want differnt temps and RH in the veg and bloom room. Not sure how to handle that if the mini is in the room.

Merlin1147 said:

Are you putting the mini split in the grow room or are you doing the whole garage? If you are worried about heat why not go LED. You’ll probably want differnt temps and RH in the veg and bloom room. Not sure how to handle that if the mini is in the room.

Click to expand...

I would love to go led but I’m on a budget for this room build and working with the equipment (lights, etc) that was gifted to me, at the moment.

Mini in flower room.

Didn’t think about humidity.

And this my friends, is why I’m talking this over....

I used a 1.1kw (thing that’s 1t to use?) , with a 1000w hps , 600w hps and a 250w cfl , in a room a little bit smaller then that , but that split system was a life saver I sat in my room over last summer (a beer cold air and growing trees , I loved it ) , stick with a reputable brand (Mitsubishi pref) and you’ll do fine with the smaller size

You are going to need frequent, depending on how tight you make it, fresh air exchange in the rooms so you dont deplete the O2. Do the HID lights have air cooled Hoods? That would be ideal. Another possiblility is to use a couple of the portable ac/heater for a lot less. Buy a spare. They have external ducting. Some come with a dehumidifier mode but you have to manually switch modes so probably better with separate unit for that

Dont forget to spec a unit that runs low ambient (winter) and has auto restart after power outage. I would use a good brand, Mitsubishi makes the best.

They make some 18000 btu/hr units. Those are 1.5 ton