Aluminum Foil Lining?

Discussion in 'Grow Room Design/Setup' started by FrickinA, Mar 27, 2012.

  1. #1 FrickinA, Mar 27, 2012
    Last edited by a moderator: Mar 27, 2012
    I am a new grower building my first grow cabinet. It is a 3'x4' cabinet that is 6' high. I have begun lining it with aluminum foil because I read that is a good cheap alternative to mylar. Now I am finding conflicting info on aluminum, saying it creates "hotspots." I dont understand how if aluminum is LESS reflective than mylar it could somehow concentrate the light MORE than mylar. Can anyone clarify who has used aluminum foil, that detail has been lacking in everything else I've read? I am trying to include a picture to show how I am doing it

    I should add that I am using 600w HID lighting, definitely using HPS, haven't decided if I'll do MH vegging or not, my ballast supports both.
  2. hotspots are created in the air pockets behind the foil because it absorbs instead of reflects. that increases growroom temps. Like when you wrap something in foil and put it in your toaster oven, the foil conducts and traps heat making it good for cooking, bad for lining a growroom.
  3. Oh okay that makes MUCH more sense. I keep seeing people referring to hotspots as burned portions of the leaves because the foil "reflects light at odd angles" or some rhetoric like that.
  4. There's a lot of that, sometimes people get excited and misdiagnose one problem for another.
  5. not that its a huge difference but aluminum foil has a reflectivity of about 88%, mylar on the other hand is into the 90s usually 95ish %.
  6. Aluminum foil's reflectivity of light is much lower than that, 55-65% range. Mylar is in the 90-95% range (that's true, mirror-finish, horticulture-grade mylar, not emergency blankets or other cheap mylar-like materials). Flat bright white paint is more reflective than foil, at around 85%.

    To the OP, you are right that foil does not create hot spots that burn the plant, that is a long-perpetuated myth.
  7. Fair enough, right now half my cab is foiled the other half is painted, given the small space and the fact that it packs 600w hps I don't think its the biggest issue, perhaps something to upgrade next grow round.

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