CFL heat shield

So I have a 4-bulb CFL light box. I basically took a shoe box, covered it in aluminum foil, and threw in 2 CFLs.



Recently I added two more, but the added heat burned some of my plants, so I have to keep them off for now :/

I would like to add a heat shield and fans to make this work with four bulbs. Glass is too heavy and expensive. Will acrylic work? I hear it insulates better than glass, but it won't melt, right?

good question...

What about lexan?

I looked it up. Lexan deflects heat very well and softens gradually from about 360F to 420F, at which point it melts. Should be fine for just 4 CFL bulbs.

Now I just have to wonder how it handles light that travels through it, and if there will be a significant reduction in the lux of my box.

Cfl's don't get very hot. What wattage cfls are you using ? I have 12 CFL's on my plants and ive only burnt the tips a tiny tiny bit once because they grew while i was away. How far away do you have the lights & are they seedlings?

its probly the aluminum foil thats burning ur plants

Stoned4Daze619 said:

Cfl's don't get very hot. What wattage cfls are you using ? I have 12 CFL's on my plants and ive only burnt the tips a tiny tiny bit once because they grew while i was away. How far away do you have the lights & are they seedlings?

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I had added 2 lights and moved them within an inch away. 4 26 watt CFLs within an inch of my plants. It was definitely too much heat. They are all seedlings about an inch and a half tall, maybe two inches.

PoBitch said:

its probly the aluminum foil thats burning ur plants

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No it's not. I made sure to wrinkle it enough so it would scatter light rather than reflect it perfectly. There was no problem with the 2 CFL bulbs in the aluminum foil reflector until I raised my plants and added two more bulbs. One bulb tipped slightly and touched one of the seedlings and burned it to death. That one's crispy. The others are suffering some tissue damage from the elevated heat, a few are singed and part of the leaves turned yellow and look bleached (the heat probably killed some chlorophyll) but hopefully they'll pull through.

I have 12 27w CFL's on a few of my Vegging Clones & they are fine ! I keep them about 3 inches away so for seedlings i would put it at like 4 or 5 inches. It's no reason your seedling are roasting when my 6 week old clones would burn at 1 inch away, that aluminum foil doesnt help much. You can buy lots of cheap fixes that will reflect & dissipate heat better. Even little scrap pieces of sheet metal would be better then aluminum foil like this

Yeah, they are about 3 inches away right now. When I add lexan and fans it should be fine.

I had the same problem , i just misted them as often as possible

I try to avoid misting them more than once a day. Last grow attempt I would mist every hour. Caused root rot. Not trying that again.