Question about temp. In my tent

I grow (in my bedroom) in a 2x4x5 tent with a HLG260XL LED LIGHT. Temps run at about 83/85 with lights on. Humidity around 50% ±. Room air conditioned at about 79’. So the question is if I opened the tent at front door during lights on and left it open during the day (lights on period) and closed it for lights out. It would drop temp a little, maybe 4/5 degrees, so would there be any advantage or could this cause something I haven’t thought of??? Oh ya I grow in FFOF,5gal pots with FF neut’s.

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Try running your lights at night, not a expert, on my first grow,just a suggestion


If there are any vent flaps on your tent you can open a top and bottom to get a chimney effect. Hot air rises so it will cool a little.
Is your whole house cooled to 79 or is it just where the bedroom temp lands?


Do you have a inline fan?

I do what you are talking about for the first few hours of light on. Or you can do as @Tinman suggests, run lights at night

Well unless I’m missing something, in an air conditioned room there is no difference in temp in the room day or night as the house is at about 79’ 24/7. I’m in Florida. It can be 90+ outside this time of year so I set the thermostat to 79’

The temp is controlled by the thermostat. So when it reaches 79 it turns off. The vents in your house could possibly be adjusted so that it blows more cold air into the bedroom than it does now. By more I mean a greater volume and not colder. Air from vents typically is 20 degrees cooler than room air. The registers have adjustments on them. Its what I do here at my house. In summer I slightly close the vents in the bedrooms and open up fully the vents in the living room area. Winter I do the opposite to warm the bedrooms more than the living room. If you can do that you could possibly lower the temp in the bedroom a few degrees. You would need to keep the bedroom door closed to keep the air trapped.

Just a possible solution. Seems you only need a little cooler.

Turn the temperature down on the thermostat then

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I grow in a little bit larger area but I run a portable A/C unit in each of my tents (vented to outside using a window kit - comes with A/C unit).

I do draw fresh air from inside the house but vent the warm air outside.
This is a bit over kill for a 2 X 2 but maybe a small window A/C unit can be used in a similar fashion. The ducting would be a bit a kludge but should work. I use a window A/C unit ($129) to keep my drying box at 60 F.

This is the best set up for a portable I have seen. Only cold air into the tent.


I was speaking of opening the TENT door not the bedroom door as the temp In bedroom is about 79’. Not doing an air conditioner. Was just wondering if opening door to tent would make enough difference IE: a couple of degree’s is this enough to be worthwhile or just wasting my time???

I am a first time grower , but have been doing hvac for 20 years, folk tend to think ac works because they feel cold air at the vent but it’s actually the warm air you are removing from the area. With that being said if you don’t exhaust the hot air out of the top of the tent , opening a the door will not do much , especially if you are at 79 degrees 24/7

Sure it will help. Esp if you aim a fan at the opening.
We are prone to offer more advice here in the forum. Lol
We love to help solve problems.

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Don’t know if temp I have risen to the level of a problem yet however just thinking outside the box to see if any fine-tuning can be done don’t know if my temperatures are too high but I just ended a good grow but if I can make a few minor adjustments to make improvements was more or less what I was looking at. So I guess the bottom line is what a reduction of temperature in the tent of three or four degrees make any real difference in the grow???

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FWIW I don’t get exercised about temperature until I hit 84F. An open tent might work although I was going to suggest a small (4") inline fan mounted in one of the top vents to remove the air at the top of the tent. I did that in my identical tent with good results.

If you’re not concerned about Odor Control should work fine but opening the tent door totally you’re going to lose your negative pressure inside tent. Good luck

I do have venting at top of tent.


I am using the same set up. I added a cool mist humidifier to use during the hot part of the day where the sun hits one wall of the closet. It brought temps down 4-6 degrees for the few hours I run it.

Mount your driver and inline fan outside of the tent