Few ideas to get around the heating issue with LED lights.

Thundercat

Well-Known Member
Question on this topic... do you think it would be worth trying to set up a small inline fan pulling warm air from the heat sinks and blowing that warm air over the canopy? You could use just a small 6 inch flex vent and a small 6 inch inline helper fan.. but would it pull off enough heat to do anything or would the heat sinks need to be enclosed for that to work?
I've seen lots of guys do this to help redistribute the heat in the tent. I think moflow might even have a fan at the top of his tent blowing the warm air back down. Obviously you aren't increasing the temps, but it pushes the warmth out of the top of the tent down towards that canopy since heat always trys to rise.

I've also seen many people swap their intake and exhaust fans from top to bottom. Instead of intake at the bottom and exhaust at the top sucking out all your warm air. You put the exhaust at the bottom and it forces the warm air from the lights and top of the tent down through the canopy.

I also think heating pads under the plants to keep the root temps up is a huge benefit. Lots of attention gets given to leaf temps but its not very often people talk about root temps and they are just as important.
 

meangreengrowinmachine

Well-Known Member
I've seen lots of guys do this to help redistribute the heat in the tent. I think moflow might even have a fan at the top of his tent blowing the warm air back down. Obviously you aren't increasing the temps, but it pushes the warmth out of the top of the tent down towards that canopy since heat always trys to rise.

I've also seen many people swap their intake and exhaust fans from top to bottom. Instead of intake at the bottom and exhaust at the top sucking out all your warm air. You put the exhaust at the bottom and it forces the warm air from the lights and top of the tent down through the canopy.

I also think heating pads under the plants to keep the root temps up is a huge benefit. Lots of attention gets given to leaf temps but its not very often people talk about root temps and they are just as important.
all great ideas! I have tried heats mats on a smaller scales and always just accomplish dried out soils lol but on a larger scale like I am doing know I bet this would work great! thanks!
 

Drop That Sound

Well-Known Member
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How about 3d printed HRV cores with metal infused filament?

That stuff is pretty expensive, but I wonder if it might transfer heat better than regular PLA or any other plastic would..
 

Thundercat

Well-Known Member
all great ideas! I have tried heats mats on a smaller scales and always just accomplish dried out soils lol but on a larger scale like I am doing know I bet this would work great! thanks!
I've only used heat mats for clones, I had to in the winter my basement grow got chilly. I just had a cheap mat that didn't have a thermostat or anything. So after drying out a batch of clones the first time, I realized it was getting to hot. So I took a handful of hydroton and put a layer under the clone tray between the tray and the mat. Fixed it right up, the small airgap and stones regulated the temps perfectly.

Maybe there could be a easy cheap way to put a layer of something between your pots and the mats to help with regulation. Maybe putting the mats on some sort of thermostat. Just a couple brainstorms for ya :).
 

cdgmoney250

Well-Known Member
Depending on the size of the grow and how much wattage being used, most growers should be able to maintain temps just by closing up and insulating the grow space/ limiting extracting for cooling. Most of the electrical equipment used (including lights) will generate plenty of ambient heat in grow space. If you’re equipment isn’t heating your space properly, you likely have too much cubic footage for your grow space, don’t have enough insulation, or you’re room isn’t sealed up well and you’re losing heat to outside of the grow space.

Adding wattage to heat the grow space during lights on just doesn’t make any sense to me, nor do arguments for HPS due to the extra IR in the spectrum.

I grew in a basement in Colorado for 2 years WITHOUT central heating in the house (old mid century asbestos furnace). The flower room was sealed and insulated and cooled with a split system AC. Even in a half insulated veg room with panda plastic for a door, I’ve never had to add heat to my grow to regulate lights on temperatures, even when it was -15 degrees outside. And when a split unit goes down in the middle of winter, my basement grow room got up to 108 degrees without necessary cooling.

If your plants roots are cold, get your pots off the cold concrete floor with a plant riser or piece of foam.

Watts are Watts, especially in an enclosed space, and if you contain those watts they will translate into BTUs heating your space.

I now run a completely sealed closed loop 4’x 8’ tent, and still need about 1 ton of cooling to cool my space at full boar. With 2 650W lights, a 70 pint Dehu, and all my circulation in fans, there is a LOT of heat getting produced just from the watts in the room.
 

meangreengrowinmachine

Well-Known Member
Depending on the size of the grow and how much wattage being used, most growers should be able to maintain temps just by closing up and insulating the grow space/ limiting extracting for cooling. Most of the electrical equipment used (including lights) will generate plenty of ambient heat in grow space. If you’re equipment isn’t heating your space properly, you likely have too much cubic footage for your grow space, don’t have enough insulation, or you’re room isn’t sealed up well and you’re losing heat to outside of the grow space.

Adding wattage to heat the grow space during lights on just doesn’t make any sense to me, nor do arguments for HPS due to the extra IR in the spectrum.

I grew in a basement in Colorado for 2 years WITHOUT central heating in the house (old mid century asbestos furnace). The flower room was sealed and insulated and cooled with a split system AC. Even in a half insulated veg room with panda plastic for a door, I’ve never had to add heat to my grow to regulate lights on temperatures, even when it was -15 degrees outside. And when a split unit goes down in the middle of winter, my basement grow room got up to 108 degrees without necessary cooling.

If your plants roots are cold, get your pots off the cold concrete floor with a plant riser or piece of foam.

Watts are Watts, especially in an enclosed space, and if you contain those watts they will translate into BTUs heating your space.

I now run a completely sealed closed loop 4’x 8’ tent, and still need about 1 ton of cooling to cool my space at full boar. With 2 650W lights, a 70 pint Dehu, and all my circulation in fans, there is a LOT of heat getting produced just from the watts in the room.
CO is NOT cold lol.... try near the CA border cold is what I mean by cold. thanks for the input though!
 

Rennpappe

Active Member
Watts are Watts
No.
You must take into account the joules that are needed to evaporate water (2256 kJ/kg ).
Plants don't stand above physics.
With HPS some 50 % of the watts can be needed for evaporation. A 600 watt lamp will act as a 300 watt heating.
With LED some 80 % are needed for evaporation. You'll have little watts left for heating.
 
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