Grow light heat help!!!

7L!fTeD24

Well-Known Member
Right now I have 4 plants growing in a 32x32x63 tent. For lighting I have a vivosun 400 watt mh/hps wing reflector kit. I have a 6" inline fan and filter running also. The heat is still too high usually 85°. It's winter here so I put a box fan in the window blowing in to keep it cool. By time I wake up in the morning it's around 65°. I'm lost on how to keep it stable around 75°. I'm going to buy the cmh light If I can't figure it out. Any suggestions on how to keep heat stable? Also I want to know if the 315 watt cmh really is better than the mh/hps. IMG_20210207_090900_872.jpgIMG_20210207_090813_506.jpg
 

HydroKid239

Well-Known Member
Do you really need the carbon filter?
Right now I have 4 plants growing in a 32x32x63 tent. For lighting I have a vivosun 400 watt mh/hps wing reflector kit. I have a 6" inline fan and filter running also. The heat is still too high usually 85°. It's winter here so I put a box fan in the window blowing in to keep it cool. By time I wake up in the morning it's around 65°. I'm lost on how to keep it stable around 75°. I'm going to buy the cmh light If I can't figure it out. Any suggestions on how to keep heat stable? Also I want to know if the 315 watt cmh really is better than the mh/hps. View attachment 4818820View attachment 4818823
 

jondamon

Well-Known Member
Right now I have 4 plants growing in a 32x32x63 tent. For lighting I have a vivosun 400 watt mh/hps wing reflector kit. I have a 6" inline fan and filter running also. The heat is still too high usually 85°. It's winter here so I put a box fan in the window blowing in to keep it cool. By time I wake up in the morning it's around 65°. I'm lost on how to keep it stable around 75°. I'm going to buy the cmh light If I can't figure it out. Any suggestions on how to keep heat stable? Also I want to know if the 315 watt cmh really is better than the mh/hps. View attachment 4818820View attachment 4818823
Where is your exhausted air exiting the room?

Or are you exhausting into the room and hoping the window fan brings in cool air?
 

HydroKid239

Well-Known Member
What does that have to do with the OPs question? I'm sure it's there because he needs it.

@7L!fTeD24 Get a temperature controller. Have the box fan only turn on when it gets to a certain temp. It's going to be more stress on the fan but it'll fix your issue.
Without the filter more heat/air will be extracted... :wall: It's the most cost effective way to help the OP's issue.
and not everyone who has a filter needs it. I have 2.. don't "need" any.

Clear enough? I'm not going to type out an explanation for you anymore. The OP needs to understand, not you. Have a good one.
 

Rurumo

Well-Known Member
How hot is it inside your room? If the room itself is cool enough, then you'll need to increase the cfm inside your tent. If the room is too hot, maybe you can vent the tent outside your window. Just to be clear...you have a fan in your window blowing cold air inside of your room? Can't you just crack the window? What are your outside temperatures like? I feel like a 315 cmh does give better results than a 400 hps, but you won't notice a significant temperature drop, so it might not be worth spending the money on one until you fix your heat issue.
 

trambles

Well-Known Member
What are the outdoor temps?
Board up the window and use a jigsaw to cut a small hole in the board for the unline fan. Cut another hole in the same board, leave the screen in the window with the window open...this is assuming u have one of those inline fans that moves several hundred cfm, not a "booster fan" that is used in furnace ductwork.
Mount the fan in one of the holes so that it is PUSHING air out the window. Next connect ductwork to the fan and connect the other end of the ductwork to the TOP of the tent, the tent should have several areas for such connections from the manufacturer.
Connect the fan to a thermostat activated switch and put the probe inside the tent. Set it for say 75 degrees. U can also put a speed controller on the fan so the room doesn't get cooled down too quickly when the fan kicks on.
Now if u do it right, once the tent gets to your desired temp, the fan will kick on and pull hot air from the tent to the outdoors and cool air will enter your room through the 2nd hole u made in the window. That air will then passively find it's way into the tent. U can also run ductwork directly from the 2nd hole into the BOTTOM of the tent.
I reccomend putting a furnace filter over the 2nd hole to filter the incoming fresh air.
 

7L!fTeD24

Well-Known Member
I have the my air exhausted into a walk-in closet next to my tent. I live in Ohio so the temperature differs by the day drastically. Right now it's like 0 degrees outside.im thinking of switching my light cycle so it's off at night and on all day so I can keep a closer eye on it. This is my first grow and want it to be simple as possible. Bu that makes sense instead of having air blowing in the room from the fan an it getting to cold I can just leave the window open an it will pull the cold air in instead of it pushing too much in right? I still want to invest in the cmh because if it's getting too hot in the polar vortex were having right now then a little less heat in the summer will help.
 

xtsho

Well-Known Member
Do you have any of the bottom vents open? You need airflow to pull the heat out.

A sealed hood makes a big difference in a tent.
 

trambles

Well-Known Member
If u are exauting your hot air into A walking closet in the same room the tent is in, them that heat will make it's way back into the grow space. Do u have the heat vent or radiator that is heating the room turned off? Cuz that will also give u heat issues. How big is the room that the tent is in?
A 400 watt light only puts out about 1500btu, that shouldnt be enough to heat an entire room up in the winter time. R u running any other equipment in that same room? Computers, dehumidifiers etc?
Check those vents that ur central heat is using and make sure they are closed.
U can also dump the heat into the rest of your house if u are willing to cut holes
 

7L!fTeD24

Well-Known Member
Ya I have the heat vents cover and the walk in closet stays pretty cold. But I took the box fan out of the window and just left it open and it seems to have leveled out. The room temperature now is 70° and it's about 78 in the tent and 75 around the bottom of the pots. Sounds about perfect right?
 

Wizzlebiz

Well-Known Member
Inkbird temp controller. Set it for night at 73 plug the fan drawing cold air in into the controller.

Will cost you $20.
 
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