AC Unit Sizing and Location

[RandyWatsonJr]

Howdy

I'm trying to figure out my AC needs for my 10x10 tent. Im currently in week 4 of flower and it's been pretty easy to maintain close to 80F during the day with 65% RH, and 75F in the evening with 62% RH (Im following Athena's manual)

The weather here hasn't been too terrible so far but I know the heat is coming. I'm trying to figure out how best to cool my tent and/or lung room as I approach the finishing phase of flower as well as my drying/curing period where I would like to achieve a temp in the low to mid 60's and RH as low as 60%.

I don't have the budget for a mini split unfortunately, nor do I want crazy high elec bills by cooling my entire house to achieve my desired grow and lung room temps. I'm not using even half of the floor space in the tent so do you think I can get by with putting a portable unit INSIDE the tent while having it vent to the nearby window? Or will that cause too much humidity? If so, and I need to place a unit on the exterior of the tent, do you think I can get a small unit, let's say 5000 BTU? That's nowhere near enough BTU's for the entire lung room, however, if the unit was placed relatively close to the intake fan to my tent, would it do it's job and cool the tent enough?

Also, should I be worried about the air in my lung room becoming stale? I have quite a few fans in the lung room and typically I do not see RH higher than 55%, and on the rare occasion, it has gotten into the low 60's. My tents sf totals about 10% of my entire lung room sf. Do I need to figure out a way to exchange the air down there or is it doing that on it's own? I just wonder if my plants could be doing better if I was doing something to force the air to be exchanged for often....Co2 is something I would LOVE to introduce but maybe that'll come down the road.

And I'm not sure if it's relevant but I wanted to share that I'm currently running a tent X system for my fans and I plan to connect the AC unit to the tent x.

 

[johnnynitro]

I always run the AC outside the tent. The tent pulls in the air from the outside. (passive or otherwise) If you get a portible AC and put in inside the tent you'll have to figure out how to rout the Exhaust hose out the tent. Easier to keep the AC outside of the tent.(or in the lung room?) Just as effective. I would get at least a 10,000 BTU. I live were it's hot and have tried many different ways. AC in the room !! (not the tent) The AC will need to have an exhaust vent. (window or??) Window ACs work very well too. (maybe better)

 

[Newty]

I run a 11,000 btu portable AC along with a Dehumidifier, even with the heat from the Dehumidifier, I have no problem keeping the inside of my tents at 78 or lower in 95 degree outside weather.
My tents are in a room with door shut so I'm not trying to cool other parts of the house with it.
I leave my AC in my lung room, I use active intakes so the cooler air gets pulled in quicker. Also if you run active intake, you can run a duct right to the AC where the cold air blows for even better cooling if needed.

If you are running an AC with a controller, it needs to be either a hard switch AC or one that has auto restart after power outage.
I don't need to run the AC off my controller, I know what it needs to be at to maintain my temps.
My Dehumidifier I run off a Controller 69. It's digital but has auto restart after power outage so it kicks right back on after a period of being kicked off by the Controller 69.

 

[PooToe]

As long as you can isolate the exhaust air from the portable A/C and direct it outside you should be fine. Question is what do you do when you fill your 10 x 10? I'm guessing you have a one ton(10000btu) portable which seems to be the most common. Having it in the tent is just going to get in your way and take away whatever the footprint is of the a/c along with an access path and ducting.

 

[RandyWatsonJr]

I run a 11,000 btu portable AC along with a Dehumidifier, even with the heat from the Dehumidifier, I have no problem keeping the inside of my tents at 78 or lower in 95 degree outside weather.
My tents are in a room with door shut so I'm not trying to cool other parts of the house with it.
I leave my AC in my lung room, I use active intakes so the cooler air gets pulled in quicker. Also if you run active intake, you can run a duct right to the AC where the cold air blows for even better cooling if needed.

If you are running an AC with a controller, it needs to be either a hard switch AC or one that has auto restart after power outage.
I don't need to run the AC off my controller, I know what it needs to be at to maintain my temps.
My Dehumidifier I run off a Controller 69. It's digital but has auto restart after power outage so it kicks right back on after a period of being kicked off by the Controller 69.

Thanks man. I think I'm gonna go with a larger BTU as you and others have suggested and keep it close to my intake fan. I'm also hoping the AC unit will help dehumidify because I'm on the brink right now as these ladies are putting off some serious humidity. I'll test the AC on the computer but maybe I won't need that connectivity after all. I'm hoping to achieve low to mid 60's during weeks 8-10 to help pretty up my buds.

What do you think of me exchanging the air in my basement manually?

And thanks for the reminder on the auto restart feature. Im trying to limit my trips to Home Depot ffs!

 

[Newty]

Thanks man. I think I'm gonna go with a larger BTU as you and others have suggested and keep it close to my intake fan. I'm also hoping the AC unit will help dehumidify because I'm on the brink right now as these ladies are putting off some serious humidity. I'll test the AC on the computer but maybe I won't need that connectivity after all. I'm hoping to achieve low to mid 60's during weeks 8-10 to help pretty up my buds.

What do you think of me exchanging the air in my basement manually?

And thanks for the reminder on the auto restart feature. Im trying to limit my trips to Home Depot ffs!

Going larger is definitely the way to go, I would rather have more cooling power then I need then not enough. It won't work as close to its limits if it's a larger unit either so would be less stress on the unit itself.
Some dehumidify better then others but with my house sitting at 60% humidity, my tent was seeing 75%-80% with the AC running and lights off, 67%-73% lights on. On the cooler nights, I tried the Dry/Dehumidify only mode on my AC and it only dropped humidity 2%-3%, that's when I purchased an actual Dehumidifier.
My old AC unit lowered humidity much better then my newer AC does.

 

[RandyWatsonJr]

Going larger is definitely the way to go, I would rather have more cooling power then I need then not enough. It won't work as close to its limits if it's a larger unit either so would be less stress on the unit itself.
Some dehumidify better then others but with my house sitting at 60% humidity, my tent was seeing 75%-80% with the AC running and lights off, 67%-73% lights on. On the cooler nights, I tried the Dry/Dehumidify only mode on my AC and it only dropped humidity 2%-3%, that's when I purchased an actual Dehumidifier.
My old AC unit lowered humidity much better then my newer AC does.

So you’ve got a computer too? If so what do you have running through it and approx where are things place with respect to your tent/grow room?

 

[PooToe]

Just make sure you size the A/C to the room size keeping in mind the extra heat you'll have to contend with.

When HID was the light of choice the rule of thumb was 3000 - 5000 btu for every 1000w light you hung. With LED the heat is much less but they do still put out some heat. Usually around .28 BTU per watt. A 650w light will put off around 2300 btu.

I typically size my A/C's 30% bigger than what I actually need.

 

[Newty]

So you’ve got a computer too? If so what do you have running through it and approx where are things place with respect to your tent/grow room?

I use AC Infinity Controller 69, I have 3 of them total. I have a 8'x4' and 55"x28" tent in a 14x14 lung room.
Controllers runs the grow lights for each tent, exhaust and intakes fans for both tents, oscillating fans for both tents, humidifier for both tents, and a 4500 sq ft dehumidifier.
I don't believe my AC has an auto restart so I don't use the Controllers with it. I've run an AC in my grow space long enough that I know where it needs to be set at to achieve the temps I want so I don't need to use the Controller anyways.

The longer side of my tents where the doors are located face each other and there's approximately 5' of space between them. My AC has an exhaust that goes out the window but the unit itself sits on the floor between both tents toward one end so about 2' from each tent.
My dehumidifier sits on the other end between the 2 tents and is about 6' away from the AC.

All my other equipment is inside the tents. The tents have a holder for the Controllers, I have heavy duty power strips mounted the the top of my tents that all my lights, fans, etc are plugged into.

 

[PooToe]

All my other equipment is inside the tents. The tents have a holder for the Controllers, I have heavy duty power strips mounted the the top of my tents that all my lights, fans, etc are plugged into.

How did you hang all that stuff off the roof? I used some wire rack shelving I bought at HD for around $16.

If you look closely I also hung a smoke alarm in the tent. PLEASE, PLEASE, PLEASE do the same. I have a friend that had a tent fire and it burned down his whole house. Smoke alarm and 5lb fire extinguisher. My friends tent was in his basement and he had a 2lb fire extinguisher at the ready. It wasn't enough and he barely got out trying to save his house. Lucky for him he had informed his home insurance of what he was doing and his policy covered it but had he not he'd be living under a bridge.

 

[Natep]

I wish someone would make a ac unit I could duct into my tent with a remote thermostat.

 

[PooToe]

I wish someone would make a ac unit I could duct into my tent with a remote thermostat.

If you're handy you can use a portable A/C and place a thermostat driven damper in front of the A/C cold air out along with whatever length of duct you need to reach your tent port. I would also cut in an inline booster fan to suck most of the cold air in and keep it from overwhelming the duct volume. It won't seal the cold air out from not escaping into the room when the damper is closed but you can still use the conditioned air to cool the room the tent is in meaning the damper won't have to open so often.

https://www.grainger.com/product/48C159?gucid=N:N:PS:Paid:MS:CSM-2295:TVRYAD:20501231&gclid=ec9256bf4f0d135f4a5930d647b9062d&gclsrc=3p.ds&gclid=ec9256bf4f0d135f4a5930d647b9062d&gclsrc=3p.ds&msclkid=ec9256bf4f0d135f4a5930d647b9062d

 

[Putthataway]

How did you hang all that stuff off the roof? I used some wire rack shelving I bought at HD for around $16.

If you look closely I also hung a smoke alarm in the tent. PLEASE, PLEASE, PLEASE do the same. I have a friend that had a tent fire and it burned down his whole house. Smoke alarm and 5lb fire extinguisher. My friends tent was in his basement and he had a 2lb fire extinguisher at the ready. It wasn't enough and he barely got out trying to save his house. Lucky for him he had informed his home insurance of what he was doing and his policy covered it but had he not he'd be living under a bridge.

View attachment 2191474

How did those fires occur? Mars light? Electric overload?

 

[Newty]

How did you hang all that stuff off the roof? I used some wire rack shelving I bought at HD for around $16.

If you look closely I also hung a smoke alarm in the tent. PLEASE, PLEASE, PLEASE do the same. I have a friend that had a tent fire and it burned down his whole house. Smoke alarm and 5lb fire extinguisher. My friends tent was in his basement and he had a 2lb fire extinguisher at the ready. It wasn't enough and he barely got out trying to save his house. Lucky for him he had informed his home insurance of what he was doing and his policy covered it but had he not he'd be living under a bridge.

View attachment 2191474

I zip tie the heavy duty power strip to an extra roof pole that I place in the back of the tent, it's one with a dip in it to give some clearance from tent roof.
Major appliances each have a dedicated 20 amp outlet.

Great advice on the smoke detectors, never even crossed my mind.

 

[PooToe]

How did those fires occur? Mars light? Electric overload?

 

[Putthataway]

Not the first time I’ve seen someone stating a mars light lit up.

 

[PooToe]

I zip tie the heavy duty power strip to an extra roof pole that I place in the back of the tent, it's one with a dip in it to give some clearance from tent roof.
Major appliances each have a dedicated 20 amp outlet.

Great advice on the smoke detectors, never even crossed my mind.

I used a couple of 1/2" PEX clips attached to the back of the mounting plate to mount it to the roof pole.

 

[Putthataway]

I used a couple of 1/2" PEX clips attached to the back of the mounting plate to mount it to the roof pole.

View attachment 2191496

It’s code here. Mine are all interconnected. I removed everyone from the house and there was still chIrp from the house. Then there was the one that kept beeping outside and the other making strange sounds with no battery for a few weeks.

 

[Farmville]

If you’re going to dry you should use 60 degrees and 60% humidity. For that you’ll need a separate room with an ac and a humidifier and dehumidifier to control spikes and avoid mold. A small room and a 10,000 btu ac with a 100$ humidifier and 200$ dehumidifier would work. A dehumidifier with a pump would be convenient so you can run it to a sink nearby. That will be all separate than your lung room if you want to continue growing in your tents as you dry

 

[RandyWatsonJr]

If you’re going to dry you should use 60 degrees and 60% humidity. For that you’ll need a separate room with an ac and a humidifier and dehumidifier to control spikes and avoid mold. A small room and a 10,000 btu ac with a 100$ humidifier and 200$ dehumidifier would work. A dehumidifier with a pump would be convenient so you can run it to a sink nearby. That will be all separate than your lung room if you want to continue growing in your tents as you dry

I’ve never heard of someone using or needing a humidifier for drying…?

I will be using my tent to dry in. It’s got an intake and exhaust. I’ll also have 4 oscillating fans. I plant to keep my lung room at 50-55% (hopefully) and have my tent x set at 60/60% set points. I think I will struggle to achieve 60F but I’m hoping to get to the mid 60’s.

As for the dehumidifier, I for sure will have 1-2 in my lung room and I was told to even keep one inside the dry room for the first day or two just to be safe….

What do you think of this plan?