Mylar questions

i currently have 9 plants awaiting to be put outside due to weather. I have recently thought of keeping them inside under lights. I was thinking of keeping 4 indoors due to their strain (Big Buddah Blue CHeese). I have heard that mylar helps block heat from helicopters. I live in a very rich county that i know uses this technique. Im worried about having 2 400 W lamps and 4 huge plants.

Therefore, what mylar do i need to buy. I also have heard that layering your walls with multiple sheets helps. I dont have alot of money just laying around, so please help me out by only giving me good information.

THANKS

i've heard that black/white poly is good to use, with the white side facing in and the black side against your walls- i might even go a step further and have mylar on top of that.
having a smart ventilation system couldnt hurt as well, if your room is cool( better yet similar temp to the adjacent rooms) then your room wont appear to be a hotspot in your home and wont draw attention. is there a way to vent the hot air to an area that wont seem suspicious? i've heard of ppl routing the hot air out of the chimney- but that wont look good if you live in a hot environment or if its the middle of summer. also- have heard of people allowing the air to cool near the center of the house like in a basement area then exhausting it(thermal imaging can only see the transfer of heat, not necessarily through walls). just some thoughts...

If you're looking for something with insulating properites, mylar isn't the tree you should be barking up. Even as far as reflectivity is concerned, it's only marginally better than flat white walls, and that's if you can get it to lay taught without a bunch of wrinkles in it, or water/spray spots on it. You need to look into INSULATION, if that's what you're trying to do. If memory serves correct, there's someting called or made by Tyvek that is a semi-rigid form of insulation that can be easily mounted on ceilings and walls.

i have my growspace in a basement and the room is not very warm at all compared to the other basement areas.

OG WINK said:

i currently have 9 plants awaiting to be put outside due to weather. I have recently thought of keeping them inside under lights. I was thinking of keeping 4 indoors due to their strain (Big Buddah Blue CHeese). I have heard that mylar helps block heat from helicopters. I live in a very rich county that i know uses this technique. Im worried about having 2 400 W lamps and 4 huge plants.

Therefore, what mylar do i need to buy. I also have heard that layering your walls with multiple sheets helps. I dont have alot of money just laying around, so please help me out by only giving me good information.

THANKS

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mylar does not block the heat from an infared gun. all it is meant to do is reflect light. if you are worried about the police using infared, try this stuff out http://www.discount-hydro.com/productdisp.php?pid=552&navid=33

Just keep your MOUTH SHUT and buy a good air filter and you will be fine!!

Nobody is going to care about 4-8 plant indoors. At least not where I am from.

tyvek isnt what your lookin for, i built houses this summer and tyvek was the weather wrapping we put around the outside of the house between the plywood walls and the siding, that stuff wouldnt do much for the reflection/ absorbtion of heat AT ALL.

that stuff in the link above looks like the stuff to get, bit pricey tho'
Above all tho' the police bust grow's based on information recieved then they might have a look at heat leaks. TELL NO-ONE what you are doing however tempting it might be to brag about growing a monster mother plant, People will always let you down even the one's you think you can trust, i know this from experience

Aluminized Mylar is better at reflecting IR than it is visible light.

Aluminum is excellent at reflecting IR light(97%), visible light(90%), and even quite good with UV light(80%).

Like the link docd187 provided, aluminum is what's blocking IR. Even aluminum foil(Reynold's wrap) blocks 97% of IR. As it's ~92-99% pure aluminum(among various foils). Reynolds is 98.5%.

Mylar that has been metallized with aluminum will converge to an aluminum mirror the thicker the coating of aluminum that is used. Thinner Mylars have higher transmissive coefficients(amount of light that goes through it). For example, you can get window tinting for cars and homes that uses the same technology to create metallized Mylar, but with much, much thinner layers. The two popular metals are tin and aluminum. Tin is great at blocking visible light(it's a white metal), but allowing much more IR/UV than aluminum.

so your saying, i could use rolls of aluminum foil, and since its so cheap probally double layer it, and it would block IR? does anyone else think this will do the trick?

Less than 3% of IR rays would penetrate Al foil. Two layers could theoretically block 99.9%.

where did you find those stats at, cause im just curious?

i wouldn't worry about 2 400watt lights...... i'm sure your government has bigger fish to fry. mylar should be placed on windows to retain heat because most heat picked up from thermal cams comes from your windows....just a thought.

OG WINK said:

where did you find those stats at, cause im just curious?

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It's pretty well known bare aluminum has an IR emissivity coefficient of .02 to .04.

http://www.engineeringtoolbox.com/radiation-heat-emissivity-aluminum-d_433.html

http://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html

This site hurts my eyes: http://www.infrared-thermography.com/material.htm

How emissivity relates to reflectivity:
http://scienceworld.wolfram.com/physics/Reflectivity.html

.03 * .03 = .0009 = .09%, or .1% emissivity, meaning 99.9%(or 99.91%) reflectivity, theoretically