Thread: Reflectix or white paint?
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Old 02-01-2007, 12:28 AM   #16
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Quote:
Originally Posted by knna View Post
As you said, if direct lighting isnt phoinhibitive, reflection either. Not concern about, just even lighting is more efficient
I agree.



Quote:
Originally Posted by knna View Post
But there some reason to consider lighting/ventilation depending of the scale. Basically, due to small cabs are often overlit, and have more watts per cubic ft, but cost per unit surface of reflectance material isnt relevant, while in large grows its more relevant.
I am not sure why it is desirable to add reflective surfaces to a grow that is already overlit?

Cost of initial installation depends on the application. It may be initially less expensive to add white paint (and possibly barite) to a closet or cab. In larger scale room-within-a-room style grows, reflectix is rigid enough to serve as a wall with a minimum of external support, so may be cheaper than wallboard + white paint. At the same time, it is flexible enough to eliminate 90 degree corners, or build parabolic reflectors. In the longer term, reflectix is easy to salvage, and reuse, and has a much longer useful life than white paint. So taking depreciation into account, the long-term grower may find that reflectix to be much a better investment.

Also, if flat white paint + barite is as reflectiive as aluminized mylar (reflectix), then arguments based on heat retention hold little water. 99% reflective is 99% reflective, and unless the reflectivity of white paint drops off in the IR, then both will reflect radiant heat similarly. So the difference is that reflectix, as an insulator, will inhibit conductive heat exchange between the airspace and the walls more than will white paint. So that keeps the heat in the airstream where it can be exhausted, rather than allowing it to be absorbed and re-radiated by the walls. The latter situation may be desirable in some cases but in most cass the former is preferable.

Quote:
Originally Posted by knna View Post
Of course reflectix is a good choice, but the mix latex flat white paint+barite is far cheaper, more reflective (or same, but not less), not insulator, with far easier manteinance and having a near perfect lambertian reflection.
These are good points, but very arguable. Having used all three (but not barite), I very enthusiasticallly recommend reflectix over both white paint and mylar for most applications.



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