Reflective material

[Mind Grenade]

Ive have a couple quick questions. I picked up a couple car sun reflectors from a thrift store.
Would these be good to put on walls of grow cab or not? Is the reflectivity worth it? Its looks like it would be good enough. and last one, Would it create hot spots like aluminum foil? or is this better cuz its not crinkly?

 

[Green Smoke]

There are people who have done it, but from reading on these forums they dont rate as good as 1) mylar and in second is 2) flat white paint. If you search there is a thread somewhere where they came up with some reflection data on alot of materials including tin foil, but 1 & 2 were those listed above.

 

[Goober23]

Go for it. It will probably be more reflective than nothing and you already bought 'em.

 

[Mind Grenade]

awesome thanks guys. I think imma go for it for my new upcomming micro cabs.

 

[closettoker]

Mind,


You can head down to wallmart or any sporting goods store and get an emergency blanket. They work just fine, its not as thick as mylar but works just as good. Like someone said before FLAT white pant works good too. I think the emergency blanket is about 3 bucks.

Closettoker.

 

[Green Smoke]

You can head down to wallmart or any sporting goods store and get an emergency blanket. They work just fine, its not as thick as mylar but works just as good.
Closettoker.

Don't be fooled, it has been discussed and researched to death. Nothing, and I mean nothing, is just as good as mylar. It is the almighty cadilac of reflection. It's expensive and a pain to work with, but it's still the best. Flat white paint works better than the sun reflectors you have.

 

[Mind Grenade]

yes, mylar > everything. Who knows, i might end up getting it. I still dont have my cabs yet.
I did go down to walgreens and they did have an emergency blanket but they didnt have them seperate...So id have to buy a $20 first aid kit which i wasnt gunna do.
So flat white paint would be better to use? By a huge difference?

 

[Green Smoke]

yes, mylar > everything. Who knows, i might end up getting it. I still dont have my cabs yet.
I did go down to walgreens and they did have an emergency blanket but they didnt have them seperate...So id have to buy a $20 first aid kit which i wasnt gunna do.
So flat white paint would be better to use? By a huge difference?

From my reading on these forums, flat white paint is the cheapest way to go. A little work intensive, but second best to mylar.

 

[fatigues]

Flat, thin mylar is easily torn. It is hard to install and hard to clean. For all that, it is better than most any other choice - most especially the aluminum foil that we still see installed from time to time by noobs on ICM.

But if you are going to install a reflective surface, choose the best one there is. The best choice is Reflectix, either in insulated bubble wrap form or in the radiant heat barrier version of the product. In either case, Reflectix is a superior mylar product and the best reflective material on the market for use in grow cabinets.

In both variants of the product, the mylar finish on Reflectix is pebbled for better diffuse light reflection (Mirror style reflection you get from flat mylar is inferior for grow purposes. Yes, really.). Moreover, Reflectix is thicker and much easier to work with. It installs cleanly and with a minimum of fuss. It can easily be cleaned, too.

Yes, Reflectix is more expensive, but worth it. If you are going to the trouble of building a grow cab - do it right.

Reflectix is available at Home Depot in the HVAC and Roofing sections.

 

[Mind Grenade]

No shit? I was looking that the stuff couple days ago and thinking it was a good idea.
http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053
But i didnt kno for sure cuz its like insulation. Thanks a lot fatigues, great input. I did not kno about the pebbled surface being superior.

 

[InducedSerenity]

Another vote for Reflectix! I just lined my PC cab with it. You get the reflective benefits Fatigues mentioned as well as sound / heat insulation.

 

[Mind Grenade]

Thanks InducedSerenity, I appreciate your vote. These car reflectors were only a buck so its not a waste. I'm going Reflectix cuz i alrdy need to go to home depot for other supplies . I dont have a hydro store anywhere close that i kno of to get mylar at.. so getting everything i need at one place is great.

 

[fatigues]

Thanks InducedSerenity, I appreciate your vote. These car reflectors were only a buck so its not a waste. I'm going Reflectix cuz i alrdy need to go to home depot for other supplies . I dont have a hydro store anywhere close that i kno of to get mylar at.. so getting everything i need at one place is great.

Just recognize that there are two versions of Reflectix. Both are equally as good at light reflection (and light proofing), but have different secondary properties:

1 - Double Reflective Insulation: ("DRI") This is available in the HVAC section of Lowes and Home Depot. It comes in rolls of varying lengths, but the key is understanding what it is.

It is mylar on both sides, so it blocks heat and light energy coming into and out of your grow cab or 5 gallon bucket. The mylar is sandwiched on both sides over top of a bubble wrap style insulating material. This makes Double Reflective Insulation quite thick. It insulates against heat transfer and also muffles sound, increasing stealth in most cabinets. It is relatively thick, so when installing in the interior of a small cabinet on all six sides, you have to take the thickness of the material into account too when planning your build.

DRI Reflectix is, generally, more expensive than Radiant Heat Barrier Reflectix.

Provided you budgeted the space to install it, DRI Reflectix is extremely sturdy and far easier to install than virtually any other reflective material you could name.

2- Radiant Heat Barrier: This version of Reflectix is also double sided - but it lacks the bubble wrap insulating core in the DRI version of Reflectix. It is much thinner.

In most cases, this is great. It saves on space when installed and is somewhat cheaper to purchase. But because it is thinner, it is more difficult to handle and will tear far more readily. Still, I think it is more sturdy than 1mm or 2 mm mylar. It lacks the R factor in the DRI insulation version of Reflectix, and does not muffle sound nearly as well as DRI.

It is intended to be laid down on top of a plywood roof, affixed with staples so that it lies underneath the shingles.

Radiant Heat Barrier is cheaper than DRI Refectix. You can find it in the roofing section of Lowes and Home Depot.

 

[Mind Grenade]

The one i was planning on getting was option number 1. Is that the better of the two?

 

[fatigues]

The one i was planning on getting was option number 1. Is that the better of the two?

There is no "better". It's what you want to do with it that governs your choices. If the insulation is helpful to you and you want that feature - then that's the "better" choice for you.

 

[Crake]

I've always wondered--what about mirrors?

 

[ScrubNinja]

I've always wondered--what about mirrors?

No, mirrors eat light. I think because the reflective coating is behind a layer of glass. So the light has to go through a layer of glass, then be reflected, then that has to go through a layer of glass again.

Furthermore

Reflection of light is either specular (mirror-like) or diffuse (retaining the energy, but losing the image) depending on the nature of the interface.

So I read that as; it's ability to reflect an image has little impact on how much energy it actually reflects.

Edit: I also wanted to say, don't forget panda film. It's less reflective than mylar, but more reflective than white paint. I like the stuff.

Edit edit: And another thing to note - that radiant heat barrier stuff is not the most optimal choice. You would want something that reflects luminous energy but not radiant energy. I'm talking optimal here, I'm sure that stuff works great anyway.

 

[staff11]

Yup I use reflectix too, works great!

 

[ICAN]

yes, mylar > everything. Who knows, i might end up getting it. I still dont have my cabs yet.
I did go down to walgreens and they did have an emergency blanket but they didnt have them seperate...So id have to buy a $20 first aid kit which i wasnt gunna do.
So flat white paint would be better to use? By a huge difference?

I got a large mylar blanket from amazon for about $5 including shipping. ..should be easy to search for. It's 84" x 52"

I'm using panda black and white for most of my cab since it's more durable, easier to clean, thicker, blocks all light transfer, and I already have it

I think one area where mylar is always good, is for radiating/blocking heat.

From what I've read, mylar is best for light, then panda film or flat white paint. And also, I've seen amazing grows using all of these. I'd be way happy with any of the grows, so I think K.I.S. and enjoyable is what counts the most. It's not like one reflector is going to double the yield over another, so whatever is in your budget and convenience and enjoyment

 

[ICAN]

Edit edit: And another thing to note - that radiant heat barrier stuff is not the most optimal choice. You would want something that reflects luminous energy but not radiant energy. I'm talking optimal here, I'm sure that stuff works great anyway.

That is worth being aware of also (and I now remember that's one reason I didn't go with mylar for my walls)... if mylar is used in a cabinet, then it will reflect back 90%+ of the heat back to the cabinet. With Panda film or paint, more of that heat can exit the cab.
I don't know how much heat would actually exit though, and if it's different for a cardboard box, plastic can, or wood cabinet.



Quote:
"Reflection of light is either specular (mirror-like) or diffuse (retaining the energy, but losing the image) depending on the nature of the interface. "

Panda film and paint also have the benefit of being easier on the eyes since they're not specular.