ransley wrote:
On Jul 8, 9:08 pm, mike wrote:
ransley wrote:
On Jul 8, 6:13 pm, mike wrote:
The front of my house faces the evening sun.
When it's 100 outside, the brown front door is 184 degrees F.
Stuck a square of white insulation board in front of the door.
It got up to 107 degrees.
The light-gray house is at 164 degrees.
I started thinking about painting the front of the house white.
Did some online research and found mention of paint that's highly
reflective in both visible and IR parts of the spectrum,
but nothing on where to buy it.
Most info was about coatings for roofing.
There's even some ceramic sphere additive that claims to
cut solar heat gain to near zero. Seems like if this worked
as well as they claim, it'd be everywhere. Went to big-box
stores and dedicated paint stores. Nobody heard of it.
Will repainting the front of the house buy me anything?
The walls are R19 and the windows are low-E R3.3-ish with SHGC of .3.
Door is fiberglass r5-ish.
Reflective paint recommendations?
Thanks, mike
Gloss is reflective, if your door was gloss brown it would be maybe
5-20f cooler but white is best and will be nearest to 100f. I tried
the ceramic beads but not in your heat or sun. You could buy a pint
and do your own test,
I haven't discovered anywhere to buy it in small quantities.

in my tests it failed.
Details???

You need trees or something to block the sun, its to bad they take forever to grow tall.

I did a stupid. Last week I trimmed the tree WAY back. Stupid, stupid,
stupid...- Hide quoted text -

- Show quoted text -

I forget the site I googled for the ceramic stuff, try variations of
Insulating Paint Ceramic Beads, I painted my basement walls and a
section of the furnace duct and with an IR thermometer showed no
difference to unpainted. They have been around since at least 85, I
figure if it really worked it would be standard practice by now in
housing and industry to use the stuff. Consider awnings

I agree...stuff that works is adopted rapidly. Snake oil takes longer. ;-)
I'm not surprised your test didn't work. As I understand it, the only good
it does is on incident radiation. Claims to re-radiate the energy back
toward the source rather than conducting it to the underlying material.
That's why it sounded good to reduce solar heat gain.

I did some quick tests painting small "swatches of wood" with two different
white paints. Both were substantially cooler than my brown door.

If you've got any ceramic paint left, try painting a small board
and sticking it out in the sun.

I hit a few garage sales today and came back with several hanging shades.
They make a substantial difference where they hang...but not practical
to hang them all over the front of the house ;-)
If i could figure out how to keep them from banging around in the breeze,
I'd be a happy camper.

mike