Cooling/ venting 5'x10' tent. Will my plan work? and a few Q's

Wassup everyone.

So I have a 5x10 tent. It's in it's own bedroom. I've been using the a/c that comes pre-installed in the bedroom to cool the room and then using an inline fan to exhaust the tent, therefore creating negative pressure and pulling to cool air from the bedroom into the tent. This was working great.

But then yesterday I heard a big banging sound coming from the a/c and it filled full of water. Now the fan sits in about 2" water when it spins. I could drain the water and the a/c seems to still work but I don't feel comfortable using it anymore.

Anyways... So I bought a portable a/c unit this morning. This unit is much more quiet, and now I don't have to worry about anyone noticing that I run my a/c 24/7. Or it blowing up and starting a fire or sumthing.

The Unit I bought has two ducts. One intake and one exhuast. I don't want to mount any ducting on my window because it will look suspicious, and my living situation requires me to be very discrete. So instead I opened the window and put the intake duct right below it, the intake can now suck in plenty of fresh air without exposing my grow. I then put the a/c directly inside the tent and ran the exhaust out of the tent and out of the room. This is working REALLY good. I have a 1000 W MH (no reflector) in the tent and with just the A/C and an oscillating fan I'm having no problem keeping temps down. I was planning on getting a cool-tube but now I'm thinkin I might not need it any more, but that's beside the point.

So now that you understand what's going on here are my questions/ concerns:

-Is the a/c unit pulling air from outside the room and blowing it into the tent, or is it just circulating the air that's already in the tent and blowing the intake air out the exhaust? Or put more simply, does an a/c unit provide fresh air/ co2?

-Does the a/c unit suck air out of the tent and exhaust it?

-In the future I plan to ad co2. Is the a/c going to break the "seal" on my tent?

-I have a pretty good tent (well insulated) but I don't think that the thermostat (on my a/c unit) will ever reach 78 degrees with the window open, therefore it will never turn off. Is this bad? I would assume so. Does anyone know what problems this could cause? Excessive use of electricity and unnecessary wear n' tear on the a/c unit is almost certain.


I'd rather not exhaust the tent because I feel that kinda defeats the point of having the a/c unit in there in the first place, and that's the only way I can think to have a sealed room so I can supplement co2.

Soooo.... Has any one dealt with something like this? I would really appreciate some advice/ answers from somebody with experience. I need to know a.s.a.p too because I have my fan off right now and if their not getting fresh air....well I need to turn that son' of a bitch back on.

Muchos Gracias in advance,


p.s. Sorry if I'm a bit long winded. I musta smoked 10 bong loads while I was writing this.

You absolutley need to exhaust the air in your tent. Period. If the spent air in your tent is exhausted into the same room your tent is in ( that houses the AC unit) You are recirculating your exhausted air back into your room. Not what you want. Try exhausting your tent through a heater vent in the room. All the parts you need to do this can be found at home depot ( minus the inline fan you will need to exhaust with).
About the co2... If your ac unit only pulls air in through the one intake tube you have, then you are fine. just make sure that when your co2 regulator comes on, your exhaust fan is timed to shut off. You don't want to send your gas straight out of your room before the plants get a chance to use it.

The ac unit came with the two ducts? What's the brand and where did you get it?

Hey Kbo. Thanks for the quick response. My exhaust fan is now back on. But it's sucking my nice cold air out.

The a/c unit is actually in the tent. I put the a/c intake directly below an open window and I'm exhausting it through a hole I cut in the bedroom door.

Like this:

Window >a/c intake (ducting leads into tent)>a/c unit> a/c exhaust (ducting leads out of tent and out of room)

So, there's plenty of fresh air in the room, I just want to make sure it's getting in the tent.

I don't really need my a/c when the lights are off. If I wanted to supplement co2 would this work? Have my inline fan provide co2/ fresh air via intake/ exhaust while lights are off. Then when lights turn on also turn on the a/c on and turn off the fans. About how long would I need to release co2 (I don't it to be exact, I could look up the formula, I just want a rough estimate? My tent is 5x10x7 so 350 cubic feet. (I think) Do I supplement during the entire day-time cycle, or just temporarily. I don't have the cash for an expensive controller so I'll be using the timer method for my co2 reg and fans.

Hasbroh said:

The ac unit came with the two ducts? What's the brand and where did you get it?

Click to expand...

Ya, two ducts. Maybe it's not called a duct when it's attached to an a/c. I dunno. But it has a 5" intake anda 5" exhaust. The brand is: Royal Sovereign. The model is ARP-1000EX

sencinitas said:

Ya, two ducts. Maybe it's not called a duct when it's attached to an a/c. I dunno. But it has a 5" intake anda 5" exhaust. The brand is: Royal Sovereign. The model is ARP-1000EX

Click to expand...

Thanks. A little pricey but figured they would be.
The motherlode of selection:http://www.portableacguide.com/models

i used a portable ac in my grow once. big thing i found was that plants directly in front of the ac did not do as well as those that were slightly farther back.

as far as intake is conserned i reccomend building a window box, crack the window, and hang some bamboo blinds or something (the blinds that dont open) build a wooden box that fits in the window frame and attach your ventilation to that.

yes if you bring in hot air from outside it will make your ac work harder and it may never shut off, this can decrease your ac life but will be fine for your plants

plants dont breath co2 at night so dont waste your gas

if you want to eliminate your intake you can form a sealed growroom, that cleans and recirculates air using your existing fan with a filter, you must make sure to supplement plenty of co2 and maintain temperatures and humidity if you cannot control these factors your better off using an intake and exhaust.

I really can't vent through the window. Has anyone tried the single vent type? I don't quite get how they work but outside here is 110 in the shade. What shade? My room is 88 right now and will stay that way until around 3:00 -4:00 am.

Sencinitas. they all seem to be around 50 decibles. Sounds kind of loud, especially in a bedroom?

Is your exhaust blowing air into the room that your grow tent is in????

You can get cheap co2 buckets from any hydro supplier, These automatically disperse the right ppm levels of co2. Just make sure when you use it that you turn off your exhaust fan! Respect

Hasbroh said:

Thanks. A little pricey but figured they would be.
The motherlode of selection:http://www.portableacguide.com/models

Click to expand...

No problem. I got it on Craigslist for $120. That's where I got most of my equipment. All under 50% retail.

Hasbroh said:

I really can't vent through the window. Has anyone tried the single vent type? I don't quite get how they work but outside here is 110 in the shade. What shade? My room is 88 right now and will stay that way until around 3:00 -4:00 am.

Sencinitas. they all seem to be around 50 decibles. Sounds kind of loud, especially in a bedroom?

Click to expand...

Never tried the single vent. Not sure exactly how they work. You could try finding someone that's selling one on ebay or Craigslist and asking them. The a/c is definately audible but with the door closed it's really not so bad. No one sleeps in the bedroom. It's a dedicated grow room. 88 degrees is way too hot without co2, maybe with it too, not sure.

Could you vent through the door. I cut a 4" hole in my door for my a/c exhuast and ran the ducting to it. The door can be easily patched in the future and no one will ever know.

kbo ca said:

Is your exhaust blowing air into the room that your grow tent is in????

You can get cheap co2 buckets from any hydro supplier, These automatically disperse the right ppm levels of co2. Just make sure when you use it that you turn off your exhaust fan! Respect

Click to expand...

No. The A/C exhaust blows out of the room(through a hole in the bedroom door). It blows really hot, I figured if I exhuasted into the room it would be like having a heater in there.

I'll look into the co2 buckets. But I can get a co2 bottle and reg for $120 on C-list right now. So if that would work better I'd rather do that and have it be automated.

namtih024 said:

i used a portable ac in my grow once. big thing i found was that plants directly in front of the ac did not do as well as those that were slightly farther back.

as far as intake is conserned i reccomend building a window box, crack the window, and hang some bamboo blinds or something (the blinds that dont open) build a wooden box that fits in the window frame and attach your ventilation to that.

yes if you bring in hot air from outside it will make your ac work harder and it may never shut off, this can decrease your ac life but will be fine for your plants

plants dont breath co2 at night so dont waste your gas

if you want to eliminate your intake you can form a sealed growroom, that cleans and recirculates air using your existing fan with a filter, you must make sure to supplement plenty of co2 and maintain temperatures and humidity if you cannot control these factors your better off using an intake and exhaust.

Click to expand...

Hey Namtih.

I was actually concerned about this exact thing. The temps directly in front of the the cold air vent are WAY lower than the rest of the room. I have a small fan blowing on the vent to help disperse the cold air.

Great idea on the window box. That's my project for tomorrow.

The a/c will just have to suffer at the lady's expense. I'm sure it'll understand.

Hmmm interesting.... What do plants breath at night? Nothing?

A sealed room is what I'm going for. In a sealed room, are temp and humidity the only two factors during the dark cycle. Or is some kind of ventilation still required? In a sealed room do you just turn the co2 off when the lights go off, or do you have to turn a fan on? I realize that's almost the same question so feel free to just answer once.

My a/c is 10,000 btu's (or close) which is more than enough to cool/ dehumidify my entire room, So far with the a/c in the tent I'm having no problem controlling the tents enviroment. I don't know the exact temp/ humidity but it doesn't seem bad. I'm getting a room thermometer and humidity meter either tonight or in the morning, so I'll know for sure.

Edit: (Just in case anybody reading this had the same question I did) I answered one of my own questions. Plants breath oxygen at night.

A little off topic but, Is there a way for me to reply to/ quote everybody in one post?

I found this thread.

https://www.rollitup.org/grow-room-design-setup/435124-co2-exhaust-2.html

It has some very helpful information.

Turns out I got the right kind of a/c. I just tested it by turning all my fans off, completely sealing the tent , and hotboxing it. The a/c didn't suck anything out.

at the bottom far right of your post box is the quote sign + hit that in order of your multi quotes and on the last quote hit the reply with quote.