foil faced insualtion, room divider

Has anyone used foilfaced insulation in their grow rooms? Does it reflect much light?
(i know it also reflects heat,but i will vent)

I was going to use it to divide up my grow room, making smaller area so i don't waste any light.

just wondering if anyone else uses it

Aluminum foil is an excellent reflector for all radiance. It reflects radiant heat(IR:infrared) just like light, as both are electromagnetic. Bare mirror-finish aluminum(most foils are 92-99% pure Al) is up to 97% reflective for IR heat waves, and up to 91-92% for visible light. Foil is made by a process of combining two films into one. A large, smooth, polished roller on top, and an unpolished surface beneath meld them into a single film. This is responsible for imparting foil with the well-known near-mirror shiny polished look on one side, and a dull matte appearance on the other.

The side of the foil isn't significant for radiance blocking; however, the shiny side is highly specular and is superior at precisely reflecting light with a greater intensity. Crinkled, bubble-wrap type/insulation, foil is crinkled for the purpose of diffusion, so radiance is not reflected as intensely in any one direction. It is still highly effective. The crinkles do not significantly change the intrinsic reflective properties, but only the direction at which reflected photons(light, radiation) are sent.

Similar surfaces are seen in dimpled hoods, the purpose is the same, diffusion/scattering/spreading of light, usually used with a high-intensity(HID) source. Fluorescents are rarely found with dimpled hoods, as they reflect significantly less intense(concentrated) radiation, as they have a much wider, more even dispersion. As such are not ideal, as fluorescents themselves are not as intense. As any HID grower will tell you, "intensity is the bee's knee"(ok, maybe not exactly). Usually the idea is to concentrate the fluoro intensity to create a more viable, productive and intense light. Actually reflecting it back upon itself precisely and intensely, increasing lux significantly.

HID growers make hot spots, fluoro growers make sweet spots.

tin foil blows
cok

sweet nice info bro,

this stuff is 1"thick foam 4'X8' both sides are highly reflective, so i'm gunna rock it.
(also 2'x8' and in thicknesses of 1",1 1/2", 1 3/4", and 2"
like 20$ a sheet from the local lumber yard

its not "tin foil", we use it in house insulation under floor for reflecting heat back up at the floor, works great

pictures so we're all on the same page

flgrower said:

tin foil blows
cok

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Tin foil is made from tin. From the ore cassiterite.

Aluminum foil is made from 92-99% aluminum(Reynold's Wrap, if you must insist on mislabeling... is 98.5%). It comes from the ore bauxite. Aluminum is what makes reflective Mylar reflective, Foylon is laminated aluminum foil, and reflector hoods are typically an alloy of aluminum. Higher end models are coated with 99.9% pure aluminum, if your wallet agrees, and then a dielectric coating is usually applied to enhance radiant reflectivity to a more even and intense level(pretty much 95% from 400-700nm wavelengths). Cheaper models merely coat them with magnesium fluoride, which, as the name suggests, fluoresces(glows). But it's not as even, intense, or durable as dielectric coatings.

You can get reflective sheet aluminum, which is thick & rigid and probably a hundred times as durable as any of aforementioned foils/mylar. Oh, you can also get them with highly efficient dielectric coatings, unlike the foils/mylar. And it's probably a hell of a lot cheaper than reflective Mylar.

Anyway. Tin foil and aluminum foil are not the same thing. And not very similar in reflectiveness over wide spectrum comparisons. By that, I basically mean aluminum is vastly superior to it, across most of the entire EM spectrum.

GrowRoom Reflectivity
Choosing the right surface for the walls of your grow room is very important, as up to 40% of your total yield comes from the edge, and the right wall surface can increase the amount of light those plants receive by up to 30%! Artificial lighting diminishes exponentially with distance, so it is important to ‘contain’ as much of this light as possible, and direct it accordingly. Reflective surfaces also help illuminate the lower portions of the garden, providing lower buds with light and heat energy.

To get the best results with your light and walls, it is important to get the walls as close as possible to your garden to ensure the least amount of light is wasted. As a caveat, the percentages provided are only useful as a general guideline, as they present the range of reflectivity of the particular surfaces. The high percentage presents the best possible circumstances for that material (for example a 99% reflectivity rating for mylar sheeting would be under ideal conditions - no creases, completely flat, no discoloration, etc).

The best way to determine how well your grow room walls reflect light would be to purchase a light meter and measure your light directly; then take an opaque board and hold it a few inches off one of your walls with the light meter below the board in such a fashion that the light reflects off the wall and onto the light meter. You can then compare the difference between the two and determine a percentage from those numbers, the closer the two numbers are, the better your wall reflects light. It is important that in both measurements, your light meter is the same distance from the light, otherwise your results will be skewed.

Also important to note is that radiant light energy refers to electromagnetic (EM) radiation with a wavelength between 400-700 nanometers (nm) and radiant heat energy correlates to EM radiation with a wavelength between 800-2000nm.

Listed below are some of the most commonly used materials used for grow room walls:

Foylon:

A more durable version of mylar, made of spun polyester fabric and reinforced with foil laminate. Foylon is resistant to most solutions, won't tear or fade, and can be wiped or washed clean.

A great solution for growers who are interested in long term use, and though it may be slightly more expensive than mylar, its durability will more than make up for its cost. It has the ability to reflect about 95% of the light and approximately 85% of the heat energy, so a good ventilation system should be used in conjunction with folyon.

A recommended method to attach Foylon to the walls would be using Velcro, as it makes taking it down for cleaning much easier nd reduces the risk of tearing, creasing or bending it. If this is used for your walls, making sure you get it flush with the wall with no pockets of air between it and the wall to prevent hotspots.

Mylar:

A highly reflective polyester film that comes in varying thickness, the most common being 1 and 2 mm thick. The 2mm thick mylar while not quite as durable as the foylon, is fairly rugged. The 1mm thick mylar tears fairly easily, so taking it down for cleaning is quite difficult without damaging it in the process. Both types of mylar are able to reflect approximately 92-97% reflective, giving it the potential to be more reflective than foylon, but because foylon is more easily cleaned without damaging it as well as it being harder to crease, foylon usually ends up being slightly more reflective. Important to note is that mylar reflects radiant heat energy just as well as foylon (around 85%), so proper ventilation is necessary if mylar is used in your grow room. Attaching this to walls can be done in a similar fashion as foylon, and the same caution should be used to avoid creating hotspots in your room. The 1mm thick mylar stands a fair chance of being creased or ripped in the process unfortunately, even if Velcro is used to attach to the walls.

C3 anti-detection film: (I'd sleep better at night if I had this.)

A specialized type of mylar that exhibits the same properties as the 2mm thick mylar, but in addition to reflecting approximately 92-97% of the light, it also is 90% infrared proof, making your grow room all but invisible to IR scanning. This can also be attached in the same manner as foylon or mylar, and the same caution should be used to avoid creating hotspots in your room.

Flat white paint:

Self explanatory; a great option for large grow rooms or for people who are interested in a low maintenance wall. Flat white paint has the ability to reflect between 75-85% of the light, and does not create hotspots. Adding a fungicide is recommended when painting.

Glossy and eggshell whites not reflect light as efficiently as flat white. Semi-gloss paint for example, only has the ability to reflect between 55-60% of the light. Also important to remember when using paint is that any smears or blemishes on the surface take away from how reflective the wall is so care should be taken to avoid marking or staining the walls. Titanium white paint is very reflective; however it is usually only used on reflectors due to its high cost.


White/Black plastic (also known as panda plastic or "poly"):

"Poly" is useful if you are setting up a temporary grow room or don’t want to damage the walls. Poly is easily cleaned.

The purpose of the black side is to not allow any light to pass through the plastic, which ensures your dark cycle remains dark. The white side is 75-90% reflective. Choose a 6 "mill" thickness of poly for maximum light blockage and duribility.

If this plastic is put too close to the light, you will obviously melt it so be careful!. Panda plastic does not create hotspots. Poly can be attached to the walls by using carpenter’s nails or using tape glue or similar means. This can be used as a cheap alternative to mylar if painting your grow room is out of the question.

Polystyrene Foam Sheeting (more commonly known as Styrofoam):

This is excellent for harsh environment growrooms (your attic for example), provided you have a good ventilation system and a way to keep the temperatures from rising too high (an a/c unit or similar) as it is an excellent insulator.

It is also a great material for use in a temporary setup or for use as a "travelling reflector" on a light mover, where weight is a concern. It is approximately 75-85% light reflective so it is comparable to using a flat white paint. Foam will not create hot spots. Rigid foam can be purchased in sheets, and can be used as a free standing wall or can be taped, glued or nailed to the wall, the last generally being the most successful method.

Emergency Blankets:

These are ultra thin polyester blankets that are sold in most camping stores and are constructed of a single layer of polyester film that is covered with a layer of vapor deposited aluminum.

It is not very effective at reflecting light because it is so thin. Holding it between you and a light source, many small holes are noticed at the intersections of creases and the entire blanket is translucent to begin with, this coupled with the many creases that are in it when you purchase it takes away a significant amount of it reflectivity. It is very easily creased as well which also detracts from its ability to reflect light. And while it is reflects nearly 90% of radiant heat energy, it is only able to reflect around 70% of the light.

The largest advantage of using this type of material is that it is very cheap and therefore easily replaced. Emergency blankets can create hotspots if not attached flush to the wall so it is important that no air gaps exist between it and your supporting wall. The easiest way to attach this is to use tape (Aluminum or metal tape is recommended), as it tears very easily once it is cut or punctured.

Aluminum Foil:

Aluminum foil is no more than 55% reflective - if used, make sure that the dull side is the one that is used to reflect the light. When it becomes creased its reflectivity is even lower (around 35%.) It is also very dangerous to use because it creates hotspots easily, is electrically conductive, and is a fire hazard when it is in close contact with HID lighting. Attaching this to walls is a pain and usually using aluminum tape or glue is the best way. This should only be used as a last resort, and even then its usefulness is questionable.

Brick Top posting nauseous amounts of inaccurate info yet again.

How can products that derive their reflectance from aluminum exceed it without using special coatings?

The red dotted line is Mylar.
The blue dotted line is ESR, a material from 3M that is extremely specular and a nearly perfect visible reflector.

Al is a bare aluminum mirror surface, Au is the same for gold, Ag is ... silver.



As you can maybe see, the bare aluminum surface is slightly better, but the curves are nearly identical between it and Mylar.

Mylar can be used for solar ovens with negligible difference from conventional(Reynold's) Al foil. Though many report that Reflective Mylar deteriorates from the heat and repeated use, and releases horrible smelling fumes in the process.

haha, you guess are just full of information(almost too much) mad interesting though. I'm gunna do it, my buddy has a lumens detector so i'll test how well it works, i can aways put mylar over it later.

i want it more for its structural ability and light proofness, it was just a bonus that it was reflective too

fox farms that is an interesting idea using insulation and the shiney side for reflection.. let me know what your friend finds out for the lumens.

Im thinking it would also help control heat / cold .

Yeah man good thread, I'm thinking about picking some of it up too, I've talked to people and they say it helps with heat too, i got a small closet and it gets hot in there during the summer, gonna try it as well.

glad you liked, i enjoy that the insulation is light proff as well.

unfortunaletly my buddy who has the light meter now has spider mites, so i do not want to use his (or even go near his house) for fear of contamination.

i found a horticulture lumen meter for 100 buck online when i get some money i will buy and test

can always put mylar over if you wanted, use foil faced tape to secure

I use tuff-r as well. It is great for killing light leaks,and cheap.If someone wanted to roll mylar over it..It wouldn't be a big deal at all. I tried like hell not to create any "wrinkles" in it while cutting. It makes the room look more like a science lab

No bueno on the spideys, after white rhino harvest gonna throw up the foil board and tape the seams. RIU

Yeah used the Easy Grow Lightite Diffusion, food grade good returns etc

How about a mylar curtain wall with zipper to divide room any body know where to get this I've been searching for hours can't find online

squirt1961 said:

How about a mylar curtain wall with zipper to divide room any body know where to get this I've been searching for hours can't find online

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Maybe Mylar backed but you ain't sewing any zipper or even gluing one to plain Mylar.

I did this last winter when things got too cold.....worked great! not only will it reflect a fair amount of light (flat white paint is better) but it helps keep the room warmer in the winter and cooler in the summer. Go for it.

hotrodharley said:

Maybe Mylar backed but you ain't sewing any zipper or even gluing one to plain Mylar.

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hotrodharley said:

Maybe Mylar backed but you ain't sewing any zipper or even gluing one to plain Mylar.

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I saw one online the other day and now I can't find it I believe it was 8' X 12' that would work for me. I saw zipper sections too at hydroponics store he said you just cut a tarp and the zipper comes with 6" on each side that adheres to tarp to make doorway.
Something like that would work for what I want to do.
Thinking of using silver reflective tarp just wondering if anyone has tried these and how well they hold up to regular use