mirrors reflective?

[moregreen]

hi, i was just thinking about reflective materials and thought about mirrors. i know mylar is the best way to go but do u think it would work and how well? just made me curious also never really heard about it.

 

[UKgirl420]

its the wrong type of reflection
,,the glass will asborb the light not reflect it ,,,if my memeory serves me correctly :stoned:

 

[moregreen]

ok i wasnt to sure if it would work or not i am new at this and i think i seen one today in a grow room thats why. thanks for reply

 

[Mutt]

Flat White paint gives ya the most bang for the buck..mylar being better but more expensive.

 

[dirtyolsouth]

I saw this info online and thought I'd add it to this recent post:

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Mirrors waste energy by absorbing only a small fraction of the light that falls on them.


When light, which, like radio waves, is a form of electromagnetic radiation, strikes a metallic mirror the electrons in the metal move just as they do when a radio signal strikes an antenna. Pushing electrons around takes energy, which dims the reflected image.

Metallic mirrors reflect infrared light (heat) and if your mirror has imperfections this will cause hot spots, which can burn plants. Please note, hot spots also apply to Mylar and Foil and IMO is not applicable to growers using small amounts of fluorescent lighting.


By using a mirror to reflect your light on a wall, you can test for imperfections, if you see an uneven image, with focused beams (normally located at the edge of the reflected pattern) these are known as hot spots and depending on the wattage of your bulb, may burn your foliage.
Metallic mirrors should not be used as a reflector for your grow room as minimizing light loss is important.


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[BBFan]

I saw this info online and thought I'd add it to this recent post:

--------------------------------------------------------------------------------

Mirrors waste energy by absorbing only a small fraction of the light that falls on them.


When light, which, like radio waves, is a form of electromagnetic radiation, strikes a metallic mirror the electrons in the metal move just as they do when a radio signal strikes an antenna. Pushing electrons around takes energy, which dims the reflected image.

Metallic mirrors reflect infrared light (heat) and if your mirror has imperfections this will cause hot spots, which can burn plants. Please note, hot spots also apply to Mylar and Foil and IMO is not applicable to growers using small amounts of fluorescent lighting.


By using a mirror to reflect your light on a wall, you can test for imperfections, if you see an uneven image, with focused beams (normally located at the edge of the reflected pattern) these are known as hot spotsand depending on the wattage of your bulb, may burn your foliage.
Metallic mirrors should not be used as a reflector for your grow room as minimizing light loss is important.


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Hi DOS-
I'm still researching the whole UVB issue. I've purchased a mercury vapor self ballasted 100 watt bulb that looks like it will do the trick (if I can control the extra heat it generates). Interestingly though, in looking into reflectors, it seems that white (in the case of UVB) is actually a very poor reflector and the best results are obtained from polished aluminum.

 

[Rockster]

I saw this info online and thought I'd add it to this recent post:

--------------------------------------------------------------------------------

Mirrors waste energy by absorbing only a small fraction of the light that falls on them.


When light, which, like radio waves, is a form of electromagnetic radiation, strikes a metallic mirror the electrons in the metal move just as they do when a radio signal strikes an antenna. Pushing electrons around takes energy, which dims the reflected image.

Metallic mirrors reflect infrared light (heat) and if your mirror has imperfections this will cause hot spots, which can burn plants. Please note, hot spots also apply to Mylar and Foil and IMO is not applicable to growers using small amounts of fluorescent lighting.


By using a mirror to reflect your light on a wall, you can test for imperfections, if you see an uneven image, with focused beams (normally located at the edge of the reflected pattern) these are known as hot spotsand depending on the wattage of your bulb, may burn your foliage.
Metallic mirrors should not be used as a reflector for your grow room as minimizing light loss is important.


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Thanks for that dirtyolesouth.

That is in fact total tosh,a grower myth perpetuated online.

Mirrors aren't the best but they do not cause hotspots and if anybody wants to argue thermodynamics with me is welcome to.

His first statement says mirrors are bad because they don't absorb much energy.

Duh,which means they reflect the light energy rather than absorb it.

Plain white walls are probably better but mirrors are ok.

Mirrors are fun,mirrors are cool

:holysheep: Mirror emancipation now!:holysheep:

 

[Growdude]

Here is another thread where this was discussed in detail, many fine links here to show how the light is absorbed by the mirror and that it does not reflect certain wavelengths.
http://www.marijuanapassion.com/forum/showthread.php?t=25957&highlight=mirror

Mirrors are extremely poor for use use in the grow room

The reason flat white works so well is the light is refracted off of it and not reflected.

 

[Hick]

Mirrors also come in two general categories, i.e. back surfaced and front surfaced. A back surfaced mirror is perhaps the most common form of mirror. It typically includes a piece of glass with a substance such a paint on the back side. Reflected light therefore needs to pass through the glass before it is reflected away from the mirror. Once reflected, the light passes back out through the glass. Passing through the glass (twice) creates ambiguity in the direction of the reflection. The glass bends the light to a degree, creating an imperfect reflection.
In some applications reflective accuracy is imperative. A front surfaced mirror improves reflective accuracy. On such a mirror, the front surface is as smooth as is humanly possible to increase reflective accuracy. The reflective surface is the first surface light contacts. The front surface immediately reflects the light before it passes through a piece of glass, removing ambiguities inherent when the light passes through glass. Aluminum, Al, is commonly used as the reflective surface on front surface mirrors.

A unique situation for use of mirrors arises when the mirror reflects light rays in and near the infrared and ultraviolet bands. Such a situation may arise for instance when laser beams are reflected. The problem is that aluminum is a reactive metal when in the presence of such light. A chemical reaction with aluminum and surrounding material creates ambiguities on the surface of the mirror, injuring or destroying the accuracy of the reflection. Aluminum is also easily scratched further preventing it from being an ideal material for a front surface mirror. The high reflectivity of aluminum, however, continues to make aluminum a substance of choice for front surface mirrors

hXXp://www.patentstorm.us/patents/5923464/description.html

Reflection of light is an inherent and important fundamental property of mirrors, and is quantitatively gauged by the ratio between the amount of light reflected from the surface and that incident upon the surface, a term known as reflectivity. Mirrors of different design and construction vary widely in their reflectivity, from nearly 100 percent for highly-polished mirrors coated with metals that reflect visible and infrared wavelengths, to nearly zero for strongly absorbing materials.

hXXp://micro.magnet.fsu.edu/primer/lightandcolor/mirrorhome.html

I guess it depends on the mirror

 

[pcduck]

Mirrors of different design and construction vary widely in their reflectivity, from nearly 100 percent for highly-polished mirrors coated with metals that reflect visible and infrared wavelengths, to nearly zero for strongly absorbing materials.

I wonder what the cost involved is for one of those 100% or even 90% reflected highly-polished mirrors? Mylar and flat white paint has to be cheaper.