Lights and Heat Buildup

[OlderStoner]

I have a grow area in a closet with about 12 sq ft, ceiling height 108". I'm using fluoros right now but as these small seedlings are quickly approaching the stage where I'm going to have to get serious about lighting I'm needing more information.

I just found a nearby store which sells a 250/400w switchable system which will work with HPS and MH bulbs. The price is about $200. And I'm assuming I'd have to buy bulbs for this. I think two of these would work for my setup and I'd place the lights on chains so I could adjust the elevation easily as the plants grow.

My concern is how much heat would these things build up. I can keep the closet door open all the time to let air circulate but I would need to close off the window in that room. There are at least two LE's who live nearby and a bright light like this would attract the wrong kind of attention. Even with that, I do not want to cut any holes in the ceiling to get rid of heat unless it's absolutely necessary, and then I would do it in such a way that I could fill the hole back in without having to pay $500 for a drywall guy to come in and do the plaster texture and painting.

Are these kinds of lights viable? I would want to go the 400w setup. And I kind og like the idea of being able to swap of HPS with MH when the time comes from veg to flowering.

 

[Richard Richardson]

They put out a lot of heat.

Have you thought about LED lights?

 

[Graytail]

How fancy is the closet door? You could always vent through the door, either by punching a nice 4 inch hole in it for a duct and fan, or maybe just shave an inch off the top ... replace the door when you move ...

Even with a 400W, you're going to need to vent the heat. I have a 19 sq ft room with a 7 foot ceiling and a 600W and even with a 50 cpm 4 inch duct, it gets into the 90s if the intake temp rises into the high 70s. You should look at the customary online sites for a 400W HID. You can get a 600 shipped for $120 on the 'bay (been eyeing another one for myself). If you have more capital to invest, TopLED is currently sponsoring a few 420 growers and have some mighty good prices. LEDs would be ideal for your confined space. I bet for $300 you could find a LED that would work.

 

[OlderStoner]

Thanks. Will read more about LED's. Will LED's put out enough lumens to produce good buds?

 

[Fuzzy Duck]

Bit hard to say how much a certain wattage bulb produces... but i have come across some info in the past

I hope this is helpful:
1000 Watt HPS Bulb puts off: ~3600 BTU
600 Watt HPS Bulb puts off: ~2060 BTU
400 Watt HPS Bulb puts off ~1360 BTU

This is heat energy only in addition to the light produced by the lamp.

What the BTU tells you is how much heat has to be dealt with per hour of use. BTU is a rate of heat transfer, nothing more.
A 400 watt lamp puts 1360 BTU into the environment for every hour it is on.

Your heat removal has to be sufficient to remove the heat from the bulb, the humidity from the air, and any heat from other equipment in the space.

An old thread - Bulb heat - Watts to Btu to Celsius Calculation



Achieving suitable ventilation is the question... & off cause plants need fresh air to do their stuff such as an intake.

Intake either by passive vent method or intake fan bringing source of fresh air in from the out side, you could also rig it up for inside intake... gonna want a fine mesh filter on that to stop bugs etc being sucked into grow room !

Extraction fan at top of grow area more likely with carbon filter etc... warm air rise's after all, vent warm air out side of grow area to lower temps.

Use an air cooled hood/reflector coupled to extraction fan for greater temp control.