Heat questions!


New Member
Hey folks!
I live in Ireland, a country not known for its sunny climate but we're enjoying an unusually nice, extended period of sunshine at the moment. I have a 150w hps in my 60*60*140 black box tent, that I run at night, but temps inside the tent are getting stoopid hot regardless, 31C+. There is a 10" blauberg inline fan hooked up to a carbon filter for extraction, and a clip on fan inside the tent. I leave a window and the door to the grow room open for extra ventilation but that only reduces temp by a degree or 2 at best. I want to try and maintain an average temp of 25c +/-

How do people in hot climates do it!? How do you manage to keep your temps down? I'd really like to upgrade to a 250w hid kit but the extra wattage would just fry my girls! If money wasn't an issue I'd have LEDs, but sadly it is so.... I have considered a cool tube but I don't want to lose any light intensity, 150w is small enough as is. I wouldn't mind but I went with the 150w in the first place because I wanted to avoid heat issues!
Any help, advice, it's all very much appreciated ☺️
air conditionner + humidity remover. I don't have a carbon filter. temps inside my tent is around 16-19 degree all the time. I also hve 2 fan, 1 inside and one outside. prior that, my temps was around 30-40 degree inside the tent with no air in it. i did a quick video of my setup. White Cookie 50 days setup for heat 420magazine.com - YouTube

Oh yeah so far... my electric bill is 450$ for 2 month only for that room. I have a separate meter for it since it in the garage.
Nice set up! I like what you did with the outside fan, I might try something similar myself and see if that does anything. Air conditioners are EXPENSIVE!!! Cheapest I've found so far is €400. Eh no, if I had that money spare I'd be investing in LED instead of air con, lol! :D I'll keep looking though, might get lucky in a sale. Cheers for the reply!
Cheers Pyr0! Hadn't thought of that. Last night it was 19C ambient in the grow room, 29C in the tent. I'll be switching rooms in the next few weeks, moving my little person to the grow room and tents into her bedroom, which is the smaller box room. Probably will increase the temps again but the vent is more accessible in there so I'll feed ducting from the exhaust fan into it. Should help hopefully. Once summer is done, temps will revert back to more acceptable levels.

Another question, is there any way to find out how much hotter a 250w hps is compared to a 150w? I really would like to upgrade and my veg ballast went tits up on me last week so I'm replacing it regardless. But I really need to know if it's going to get much hotter than the 150w. Ta.....
Hey mate. Got similar heat issue as you described. Using a 250w CFL light in a smaller tent and temps could rise to 30C+ before I got a somewhat good ventilation system going, still reaching temperatures of 27-28 tho on a warmer summer day. What I have done is getting more powerful fans pumping in/out air aswell as leading the warm air going out away from the cooler air thats going in by using a aluminium foil tube. Now during bloom I also have lights on during the night.

This was my first grow and I believe it will be easier during winter to control the temps!

GL Buddy!
Cheers for the reply bludmangrow! For now the problem has rectified itself, in that ambient temps have reduced so temps in the tent are maintaining themselves around a nice 26C. Like yourself I run my set up at night. I'll be moving everything into the smaller bedroom in the next 2 weeks as my little person will be taking the grow room, and the vent is more accessible in the small room so I'll run the ducting from the exhaust directly into that. Should also help with the temps! :)
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