Re: I gotta ask.....
.... generally, by rule of thumb white paint and roof surface coatings are considered about 90% reflective. Remember there are on a clear day 1050 watts M/2 of radiated energy @ sea level beating down from ol-sol. Adding aluminum might improve things by a few percentage points but is it worth the extra cost? A few years ago I did a large roof in Punta Perula... bright almost blinding when working or the roof... didn't realize how much light energy was reflected until I was looking at Google Earth a year or so ago... the area around the roof is overexposed because the camera on the satellite couldn't handle the reflected light. But we must remember too that much of the heat energy absorbed by a dark object is mostly low frequency IR energy. Over the past few days most of the built up latent heat energy has now dissipated and the noted change is significant. The ceiling went from hot to touch at 2pm to no discernible heat... huge difference.
Note: don't know about the paint, I had some, but the roofing compound (impermeazable) was cheapest right here in Melaque at Ferro Pacifico (sp) hardware store... around $650 a bucket.
Message Thread | This response ↓|