Window vs Dual Hose Portable vs Mini-Split AC

xIPhobiaIx

Active Member
What type of AC is often recommended for a sealed room with CO2 supplementation?
I want to make sure too much CO2 doesn't get sucked out of the room.

Thanks!
 

Rurumo

Well-Known Member
The people in the know are going to need more info, type/watts lighting, room size, etc.
 

PizzaMan5000

Well-Known Member
I like whatever doesn't put the house under a vacuum. Single hose portable units needs to offset the exhaust somehow, so it sucks hot outside air though the path of least resistance.

The hoses on remote units can get hot and make you lose a bit of efficiency.
A good window unit is more efficient than a remote unit.
 

xIPhobiaIx

Active Member
I like whatever doesn't put the house under a vacuum. Single hose portable units needs to offset the exhaust somehow, so it sucks hot outside air though the path of least resistance.

The hoses on remote units can get hot and make you lose a bit of efficiency.
A good window unit is more efficient than a remote unit.
What is a remote unit? And are you saying you would do Window vs Dual Hose Portable?
 

PizzaMan5000

Well-Known Member
What is a remote unit? And are you saying you would do Window vs Dual Hose Portable?
Portable would be with a hose. If it has an air inlet hose and an air outlet hose, it shouldn't create a vacuum. A single air hose is the worst.

I have had a "portable" (floor standing) unit that would shut itself off for a thermal overload. When the exhaust hose was shortened to a straight 2' run, it quit overheating. It was a big one, 10k+ btu. My 5k btu window unit does just as good of a job.

Units with a hose will list a total btu, and another value. That's how much is lost with the hoses.

A mini split won't have these losses.

If I were choosing between a window unit, or a hose-unit, I would get a window unit. Best output per watt, aside from maybe a nice mini split.
 

xIPhobiaIx

Active Member
Portable would be with a hose. If it has an air inlet hose and an air outlet hose, it shouldn't create a vacuum. A single air hose is the worst.

I have had a "portable" (floor standing) unit that would shut itself off for a thermal overload. When the exhaust hose was shortened to a straight 2' run, it quit overheating. It was a big one, 10k+ btu. My 5k btu window unit does just as good of a job.

Units with a hose will list a total btu, and another value. That's how much is lost with the hoses.

A mini split won't have these losses.

If I were choosing between a window unit, or a hose-unit, I would get a window unit. Best output per watt, aside from maybe a nice mini split.
As the 6 HPS lights are basically my heat source than with 18k+ BTUs of heat it will heat it up prob to around 120 degrees with no ventilation (this is a larger shed, fully insulated and sealed) from my calculations and with co2 I wanna get it down to 85-90 degrees but I am concerned that as it gets warmer outside (currently winter and 23 degrees) I will need more BTUs... it is so fricken hard to properly size an AC unit so I am good all year round.
 

PizzaMan5000

Well-Known Member
When running that many watts, you should definitely have ventilated hoods that are pulling from outside, and exhausting back outside (in summer). Run this at full blast.

Then manage the temperature of the room on entirely different ventilation. Over 1k watts, it's a bad idea to run the carbon filter into the hood for instance. The airflow through the filter is too much, and the room will still be hot.

Having lights on at night is obviously "low hanging fruit". Every bit of cool air at night helps.
 
Last edited:

xIPhobiaIx

Active Member
When running that many watts, you should definitely have ventilated hoods that are pulling from outside, and exhausting back outside (in summer). Run this at full blast.

Then manage the temperature of the room on entirely different ventilation. Over 1k watts, it's a bad idea to run the carbon filter into the hood for instance. The airflow through the filter is too much, and the room will still be hot.

Having lights on at night is obviously "low hanging fruit". Every bit of cool air at night helps.
Yeah but can I get vented hoods for Gavitas? I have the 1000 DE
 

PizzaMan5000

Well-Known Member
Yeah but can I get vented hoods for Gavitas? I have the 1000 DE
You're gonna struggle to keep that room cool.
Hmm. Hmmmmmmm

What's your humidity like? Maybe a swamp cooler?

I didn't realize they were unvented hoods.

I don't know how it would be possible without flir or the electric company ratting you out, or having the amperage to keep that cool. It's best to just turbocharge ambient outdoor air through some hoods, less to refrigerate.
 

UpstateRecGrower

Well-Known Member
You need about 2 tons for the lights and dehumidifier minimum. Idk how well insulated the room is or how hot your summers can get so there’s that to think about.. 3 tons should do it, but you could always go bigger if you wanted, maybe you’ll want to add a couple lights down the road? Mini split is the best way to go, they’re cheap, efficient, easy to install with basic hvac knowledge..
 

sf_frankie

Well-Known Member
I tried doing CO2 without a mini split. I could get it to work using a modified single hose portable AC but in the end it wasn't worth it. It still leaked. My CO2 generator was firing several times per hour and the AC had trouble keeping temps and humidity in check. In the end I broke down and did what I should have done in the first place and got a Mini Split. The savings were noticed immediately on my electricity bill as well. The mini split is wayyyy more efficient than the 1200w portable AC.

Plus, with 6 HPS lights you are gonna need a lot more cooling than I had for 2 LEDs
 

xIPhobiaIx

Active Member
You need about 2 tons for the lights and dehumidifier minimum. Idk how well insulated the room is or how hot your summers can get so there’s that to think about.. 3 tons should do it, but you could always go bigger if you wanted, maybe you’ll want to add a couple lights down the road? Mini split is the best way to go, they’re cheap, efficient, easy to install with basic hvac knowledge..
It is well insulated (spray foam for air seals, R-15 fiberglass, vapor barrier than 1 inch poly foam board (aluminum radiant barrier on each side).

No light or air gets in
 

sf_frankie

Well-Known Member
It is well insulated (spray foam for air seals, R-15 fiberglass, vapor barrier than 1 inch poly foam board (aluminum radiant barrier on each side).

No light or air gets in
That just means that it will hold in all the heat from those lights that much better. Its clear that you're well invested in this project. Don't cheap out on AC and get a mini split (or at the very least a window shaker or 2)
 

Herb & Suds

Well-Known Member
I see some mini splits have dehumidifying capabilities. Can this work instead of buying a separate dehu?
All A/c has dehumidifying capabilities except a swamp cooler
terrible recommendations

You have so much invested you need a couple mini-splits with remote evaporater coils probably two for each
 
Top