I have a question for tent growing. If you have your tent in a small 10’x20’ room that has A/C built into the wall that works very well, is that enough cooling for the plants inside the tent with good filtration and fans, and LED lights inside the tent? I’m new to this, and have never grown in a tent before. The tent is 4x4.
Definitely as long as the tent has an exhaust fan that cycles the air fully once every couple of min the temperature in the tent shoud be within a few degrees of the room
Thanks, Smokesdaily, that’s what I needed to know.
A good exhaust fan and a couple small fans inside tent to circulate do well. I run my lights in flower tent on at night. Helps with heat in the summer.
Thanks, 4204life. I’ve seen where several run their lights at night in flower because it saves on electricity and is easier to cool. I’m going to do that, as I need to save all I can.
If you ensure this 
you should be good. There is a formula on this forum somewhere for figuring the correct cubic ft displacement requirements for the fan you need for your exact size tent. I’m running a 6 inch 395 CFM exhaust fan on both my 2 X 4 & 5 X 5 tents (no filters) in the same lung room along with a 2 X 3 tent (passive intake, no exhaust), and I run a 12,000 btu window ac unit only. Except for a couple super hot days this past summer (outdoor heat index 113), all worked well. 
Note: I did just add the 5 x 5 this year and those couple of super hot days this summer is making me consider upgrading my ac to a 14,000 btu. With just the one 4 X 4 tent, you’ll be good.
Thanks for that advice, d-Jawz. I have so much to learn about tent growing. Right now, all I have is the tent and was planning on a 6" exhaust fan with filtration. I don’t know the BTU of my A/C that is built into the wall. It’s a window unit. It keeps that room at 70° on scorching days here, and I only have it turned up half way on medium cool. Haven’t needed to use the high setting. So, I’ll be good then with the one tent.
I’ve got a 4x4 Tent and a few more factors come into play like for instance in my case I have 2 10,000 btu ac units going on 64° 24/7 and lights off from noon to 6pm.
If the room you plan to use as a lung room has any leaks like letting cool air out or hot air in will also fluctuate inside your tent.
and I would put a fan at the bottom to help force cool air in. Just my thoughts on it. But good luck and happy growing
The room has absolutely no leaks, except maybe a tiny crack around the A/C in the wall. The room is very well insulated and has no windows. It has a very tight door to the outside with a terrific storm door, so I think I’m good in that aspect. Also, the room has only 2 outside walls. I do plan on 2 small fans at the bottom to keep the air circulated inside the tent. Thanks for your thoughts on this, every little bit helps me. Happy growing to you too.
I don’t know the answers to any of that, DanB. I’m new to all of this. I was actually wondering about the CO2, as I watch Scotty Real on YouTube. I have no idea. I have only grown in this room without a tent.
I am not trying to be discouraging just trying to help cover your bases is all.
Basically if you could keep the door to the room open at least a little bit the entire time you could circulate new air other then from the AC into the room the AC would still stabilize the room allowing CO2 and fresh oxygen into the room threw the open door. I’m assuming you have a filtration system on the tent so that will nullify smell for the most part.
You will be just fine. Anywhere low to mid 80 is a good temp in tent.
Is why I was asking the question I was, given the AC ok but how else is he going to get fresh oxygen and CO2 in that room if it’s this well insulated, when I was gonna do basically the same thing in a shed I was told without cutting a hole or something to left fresh air in and the “filtered air out” my environment would become unstable.
If I’m wrong please correct me and I will step back and learn.
Unless super hight light power, HEAVY nutes, the exchange will be plenty. Ac venting in is enough exchange. Air tight only happens when planned. Like in space or a submarine. Wont be an issue with co2. 1 cigarette smoked in a grow tent is more co2 than 5 co2 bags almost. I dont see an issue myself. Just my thoughts but you know how that is.
Ok thank you very much for the break down. And now being that I smoke cigarettes when watering and all around my plants I know for sure I don’t need CO2 supplements lol. And I also thank you for correcting my thoughts. I appreciate it.
No correction my friend. Not at all. Just observations from here. My grow room is pretty tight. Ac in exchanges the whole area very fast.
Not needed and very dangerous Grow Bro especially with your tent inside your home. They’ll get plenty of CO2 with you breathing on them 
That sounds good to me, DanB, so if I leave the door open a little that goes into it from the room that it’s built in, I’ll be ok. The room that it is built in was a big 2-car garage, when we purchased the home. The previous owners built the room. We then closed in the rest of the garage and turned it into an art studio for me, so it’s connected to the central heat and air. So I wouldn’t be letting in a lot of heat if I left that door open. I keep the central air set as 76°.
Right now, I only have the tent and it isn’t up yet. I have my GDP girl growing right where the tent will be, so I can’t put the tent up until she’s harvested , which will be probably a little more than a month from now. I will also hang her to dry in that room. So I was just trying to get all of this figured out. I’m not worried about smell, as I live out in the country with no houses near me and no one is ever in my house but my kids (they don’t live here) and they both know I’m growing. It seem that I’ve always had enough oxygen and CO2 in that room, as my grows have done ok, and the one now is a beast. I was just worried about a tent that is so enclosed. This is what I was planning on putting in it: VIVOSUN Smart Air Filtration T6 Kit 6", AeroZesh T6 Inline Duct Fan with E12 Speed Controller, Carbon Filter & 8’ Ducting, Cooling & Ventilation System for Grow Tents, Indoor Gardening, Hydroponics
Thanks for all of your input, Dan, it helps me a lot.