Sealed room question

medimaker

Active Member
Hello everyone

I'm currently in the process of a grow room makeover and so far I have pretty much an air tight 8x8 flower room. Inside will be 2 x 600 hps inside cool tubes. So far the room has no air in or out. My ac unit is a 11k btu portable style on wheel with a hot air exhaust tube vent on the back. (about the size of a small bar fridge)

I would like to use co2 but don't want to exhaust it in the ac discharge duct or exhaust fan.

If I let the ac exhaust inside the flower room the exhaust fan I assume will have to run all the time. That little ac blows some hot air out the back :evil:
However if I vent the ac exhaust out if the room then the ac will simply suck it up through it's intake and I'll lose some out the back.

Can someone please tell me how I can get into the co2 game? :dunce:
 

medicalsb420

Active Member
Step yer a/c game up. Those single hose models really complicate things. No way you can send exhaust back in room and keep good temps, even if you could Itd be a huge waste of power:( . Somewhere on here I think I read about someone modifying a single hose unit to work with co2 but not sure. IMO; sell it for as much as you can , and buy a dual hose or a mini split ac. If you just got to make that 1 work tho, maybe go over board with co2 like 15min on 15 min off during light cycle. Good luck
 

NLXSK1

Well-Known Member
Hello everyone

I'm currently in the process of a grow room makeover and so far I have pretty much an air tight 8x8 flower room. Inside will be 2 x 600 hps inside cool tubes. So far the room has no air in or out. My ac unit is a 11k btu portable style on wheel with a hot air exhaust tube vent on the back. (about the size of a small bar fridge)

I would like to use co2 but don't want to exhaust it in the ac discharge duct or exhaust fan.

If I let the ac exhaust inside the flower room the exhaust fan I assume will have to run all the time. That little ac blows some hot air out the back :evil:
However if I vent the ac exhaust out if the room then the ac will simply suck it up through it's intake and I'll lose some out the back.

Can someone please tell me how I can get into the co2 game? :dunce:


You have the wrong type of A/C unit. You will need to get a mini-split, dual hose or window a/c unit that keeps the interior and exterior air separate.
 

medimaker

Active Member
Ah ok I get it. I can pick up a dual hose, cool the room while not venting co2 and the exhaust fan doesn't suck it out either. Since it won't need to extract hot air.

Am I talking crazy? Lol
 

NLXSK1

Well-Known Member
Ah ok I get it. I can pick up a dual hose, cool the room while not venting co2 and the exhaust fan doesn't suck it out either. Since it won't need to extract hot air.

Am I talking crazy? Lol
Right, a dual hose A/C unit will act the same as a cool tube. It will suck in outside air, use it to cool off the AC coil and then ehxaust that air back outside. Then the AC will cool the room without exchanging any air with the outside.
 

medimaker

Active Member
Perfect it turns out 5 stores right around me sell them lol

Some of the claims I'm hearing about co2 have got my interested-
15% increase in yield-
Thicker buds-
Shorter flower-
I've even read about co2 at 10k for an hour is a spider mite death ray. People and pets too. I guess that's why they use sealed rooms.
 

NLXSK1

Well-Known Member
Perfect it turns out 5 stores right around me sell them lol

Some of the claims I'm hearing about co2 have got my interested-
15% increase in yield-
Thicker buds-
Shorter flower-
I've even read about co2 at 10k for an hour is a spider mite death ray. People and pets too. I guess that's why they use sealed rooms.
it might kill spider mites but it doesnt do shit for those damn gnats... Had a little generator problem that wilted my plants with CO2 but didnt kill those things.
 

DubsFan

Well-Known Member
For the record, I have a 150sqft sealed room. There are no noticable breathing holes except the outlets. My Co2 ppm's still measure the same as outdoors. Around 400ppm.

Do I use Co2? Yes. I don't crank out 1500ppm though. When flowering I crank out a total of 750ppm. Yields are fine and buds are dense. What I definately know about Co2 is that it will not make an average grow good.
 

medimaker

Active Member
I found a dual hose unit that also controls humidity and has an auto mode for both temp and humidity. That would help with climbing humidity at night when the lights go out and the basement cools slightly.

Should I still vent my cool tubes when the lights are on or just let the ac deal with it all and have my exhaust fan for when things get too out of whack?
 

DubsFan

Well-Known Member
I don't really understand your last question. I pull air in from outside, through my ducting and hoods then back outside. No air in or out.
 

1mikej

Well-Known Member
hey i modified my single hose unit to a duel hose and it was the best thing i did. it not to hard . pm me and i can walk you through it. this ac cools a room 8x7 with 2x1000watters in cool tubes and 1 x400 watter with no hood or cool tube and im in florida. it did not do this as a single hose unit.
 

medimaker

Active Member
I don't really understand your last question. I pull air in from outside, through my ducting and hoods then back outside. No air in or out.
Sorry, I should have been more clear. I was wondering if it was still worth while to run a separate sealed duct just for the cool tubes. Or with this dedicated ac simply remove the cool tube duct and let the ac cool all the hid heat.

But having thought about it, I imagine it must be way cheaper to run my spare 4" vortex and some sealed ducting through my cool tubes. Rather than have the ac on longer that it has to be.
 

medimaker

Active Member
hey i modified my single hose unit to a duel hose and it was the best thing i did. it not to hard . pm me and i can walk you through it. this ac cools a room 8x7 with 2x1000watters in cool tubes and 1 x400 watter with no hood or cool tube and im in florida. it did not do this as a single hose unit.
Too late! Lol but thanks. I gave back the portable I borrowed. Today I found a nice 3 in 1 ac. 2 hose with an auto setting that will also keep humidity in check if it starts to rise when ac isn't needed.

The room will be completely sealed now. I also picked up co2 tank and regulator today. I also just looked at the math equation that needs to be done in order to calculate co2 ppm. :shock:
 

DubsFan

Well-Known Member
Good luck. Let us know how it turns out. You can get a cheap Co2 test kit to verify the math. It's the one that uses an "air syringe" (spelling). You suck are into this syring and push it through this skinny glass tube with PPM markings on the side. After a minute of pushing air through it you will see what your PPM's are. I don't use the digital stuff. They are nice but not mandatory for most grows. If I had 8 lights I might consider getting a brain.
 
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