What colors of fiberglass shingle have the greatest reflectivity of heat from the sun’s rays? Thanks.
What colors of fiberglass shingle have the greatest reflectivity of heat from the sun’s rays? Thanks.
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Replies
I've been working on a slate roof that someone painted with AL paint. It looks terrible, but it sure is reflective.
Probably not what you're looking for...
Jon Blakemore
I never saw an aluminum colored fiberglass shingle but if they did and it worked that well I'd sure take a look at it. :o)
Painted slate. Sounds slippery.
Edited 6/22/2004 4:54 pm ET by rez
White
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
I researched this a while back and was surprised to find that, while polished silver reflected more light, white beat out silver for solar "heat" reflection.
Apparently, in spite of it's shininess, the grey base of silvers absorbs more heat than pure white.Kevin Halliburton
"The Greek comic poets, also, divided their plays into parts by introducing a choral song, ... they relived the actor's speeches by such intermissions." Vitruvious, (Book V)
I just reduced the Q to it's essence. Forget about asphalt. Forget about shingles.
What colour reflects more light ( Light energy = heat)
White is the sum of all colours so it obviously reflects them all
The trickier question might be what absorbs the most heat? Red or black?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Years ago I messed around with solar heat . Found out that a dark green would absorb more heat than black .
That makes sense to me since red is the closest thing to infa-red (heat) and red paint would reflect red, and green would absorb it.
Red... and why doesn't he just mirror plate the damn thing and be done with it...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
The trickier question might be what absorbs the most heat? Red or black?
A dark "blue purple" (make violet from equal parts red and blue, then add 50% toned [black added] blue in a 2/3:1/3 ratio).
This was our spec for the backplane color for job-built solar hot water collectors. The mix of red & blue "catch" about the widest range of light, including some UV & IR.Occupational hazard of my occupation not being around (sorry Bubba)
White and to take it up a notch paint it silver...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming....
WOW!!! What a Ride!
yeah white ....but what about all the other rays?
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
the.... "HAT"
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
Dare i suggest a tin-foil roof????
Shiny side out of course!Mr T
Happiness is a cold wet nose
Life is is never to busy to stop and pet the Doggies!!
For the whole thing or just his head????
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
I like shinny side turned in.
That way, I can see my self think
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Morning Piffin!
you up already or still??
Mr T
Happiness is a cold wet nose
Life is is never to busy to stop and pet the Doggies!!
I stayed up late to get some billing done. All those small jobs that stretched out over the last three months - I finally got them all finished and had to sort out all the invoices and such. Finall tally came to about 22 grand over four jobs - no five! The nervous energy has still got me awake.
I'll wait 'till the end of the month to bill out my main job. I can only take so much excitement at one time.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
The other thing is that I have just gotten over a lung infection and still having some asthma type symptoims and the meds tend to excite my system like speed. It's nice to be able to breathe again but I'll be glad when it all gets balanced out again.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I feel your pain!
IBecause of the sleep apnea, I need to wear a mask when I sleep.(CPAP)
every night about 3 am I wake to go pee and have a hrd time going back to sleep.Mr T
Happiness is a cold wet nose
Life is is never to busy to stop and pet the Doggies!!
The whole thing!
then you only need to wear your tin foil helmet when you go outside to get the mail.
at midnight
after secureing the perimeter
and listening for helicopters
and sweeping for electronic devices
with your flak jacket
and a life line
in a serpentine path
with a mine sweeper
and your rubber gloves on(the mailman is with THEM)
and your gas mask
and "back-up"
and a fully locked and loaded Kalashnikov
and a plastic Glock
and with the Jamming gear turned up to full
and a K-bar
or you could just send one of the kids.............
Mr T
Happiness is a cold wet nose
Life is is never to busy to stop and pet the Doggies!!
that's it... I gotta find me a kid...
All that other stuff is getting too heavy too carry...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
> yeah white ....but what about all the other rays?
Lead foil in your hat.
The "other rays"? That's why you line your hat with aluminum foil, isn't it. Or have I been doing it all these years for nothing? Or maybe your neighbors don't shoot those rays at you. :}
It's often not the neighbors... It's those others that you can't see...
but they're there doing their evil work...
Be safe wear yur hat...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming.... WOW!!! What a Ride!
So we're saying the light grey and light green are probably about the same for all practical purposes?
saying the light gray and light green are probably about the same for all practical purposes
Yes. In asphalt shingles, the pale gray is a good choice, as are the palest tan colors. For metal roofs, the best compromise (meaning customer acceptance, too) was a cream color that is/was in stock with both Alcoa and AlClad.
Out in the panhandle, chicken coops and well houses would get roofed with the pure white 3-tab shingles. This worked, some, but the roofs still seemed to melt together into one monster shingle mass.
Back when this was a hip academic topic when I was in grad school (more'n 2 decades ago), for asphalt shingles, the 'answer' was to use a layer of the aluminum-faced insulation board underneath (but over the roof deck). This limited attic heating by conduction (and radiation, some). Which is good when the subdivision architectural rules require a charcoal gray asphalt shingle. The other 'surprise" was that the silver-gray color of a weathered shingle was better than the natural color. Excepting that the flat (not glossy) finish was (slightly) more absorptive of heat. I'm not sure I'd try washing the shingles down with water seal to give them a bit of gloss . . .
Occupational hazard of my occupation not being around (sorry Bubba)
Edited 6/23/2004 11:25 am ET by CapnMac
White is the best of all standard colors (in asphalt or metal), but standard white asphalt shingles are not all as much good as one would hope. There are special highly reflective white shingles which are considerably better than regular shingles. There are also metal roofs which, despite being available in dark colors, actually pick up less heat than standard white painted metal or aluminum colored metal. The reason is that they have special paints which reflect a very high amount of infrared energy. Aluminum isn't particularly reflective in the infrared band and galvanized was as bad as dark colored standard paint.
There was an article about this several years ago in the Journal of Light Construction. There was very careful university research on this in Florida. Probably the US Department of Energy has information on these materials and tests, or an internet search might locate them.
Also, in hot climates, radiant barriers properly installed in the attic were also quite effective at reducing heat gain.
The guy that wrote that is with a state University. I think that it is Florida Solar Institue or something like that.
Shortly after that came out I did a google on the author's name or the name of the group and found much of the same information online.