This Ultra-White Paint May Someday Replace Air Conditioning

[thackney]

This Ultra-White Paint May Someday Replace Air Conditioning
https://www.smithsonianmag.com/innovation/ultra-white-paint-may-someday-replace-air-conditioning-180977560/

...n tests conducted during sunny, midday hours on the roof of a campus building in West Lafayette, Indiana, the paint kept outdoor surfaces 8 degrees cooler than the ambient surrounding temperatures. At night, the paint kept surfaces 19 degrees cooler than their surroundings.

“Our paint can lose heat by its own emission—it emits heat to deep space,” Ruan says. “With such little absorption from the sun, our paint loses more heat than it absorbs. This is really exciting for us. Under the sun, it cools below the ambient temperature and that’s hard to achieve.”

Heat-rejecting white paints on the market now are typically made with titanium dioxide, which reflects certain wavelengths of sunlight—mainly, the visible light and near-infrared wavelengths—but absorbs the sun’s ultraviolet rays, causing the surface to heat up, Ruan says.

“Commercial white paints are cooler than the other, darker-colored paints, but they are still warmer than the ambient or surrounding temperature,” Ruan says....

[Fishrrman]

I don't care WHAT color you use on a building or its roof...

In summer, in Arizona, Texas, Florida, anywhere where there's lots of sun -- it's going to get HOT inside without a/c...

[rustynail]

Sounds vaguely racist.

[Elderberry]

"the paint is not expensive,” Ruan says.

Sure fella!

Howz it work after it gets a couple of years old?

[Elderberry]

So with that fancy smantzy paint on my roof here in Houston in August with 91deg(ave) temperatures with 93 to 55% humidities(ave) I won't need an air-conditioner?

Sure fella!

[DB]

Who paints their roof?

[Elderberry]

Who paints their roof?

Aluminum roofs come pre-painted.

[roamer_1]

Ventilating the roof will do more than any paint will. Soffit vents and a ridge vent. Problem solved.

[roamer_1]

Who paints their roof?

I have painted many roofs. Your standard aluminum roof will last far longer than its paint. replace the (rubber gasketed) screws and paint it for way less than replacement.

SWP industrial DTM Acrylic for anyone who asks.

[Elderberry]

Ventilating the roof will do more than any paint will. Soffit vents and a ridge vent. Problem solved.

Years ago I saw a study in Florida of venting, not only the roof, but also the exterior walls. It showed by venting the entire exterior a remarkable amount of heat was prevented from migrating into the interior.

I saw another study that showed the cooling by training grapes to grow above the roof. And having plenty of trees also reduces the heat load on the house.

[IsailedawayfromFR]

Years ago I saw a study in Florida of venting, not only the roof, but also the exterior walls. It showed by venting the entire exterior a remarkable amount of heat was prevented from migrating into the interior.

I saw another study that showed the cooling by training grapes to grow above the roof. And having plenty of trees also reduces the heat load on the house.

Right now airplane pilots are blinded by lasers.

Just think once they overfly an entire city painted in the garish white that reflects the sun.

I can see the planes crashing from the sky like hailstones.

Maybe the solution we will see is only night-time plane travel.

[roamer_1]

Years ago I saw a study in Florida of venting, not only the roof, but also the exterior walls. It showed by venting the entire exterior a remarkable amount of heat was prevented from migrating into the interior.

I saw another study that showed the cooling by training grapes to grow above the roof. And having plenty of trees also reduces the heat load on the house.

All very true. Up in here, exterior walls run a continuous 1/2" closed foam sheath on the exterior walls and roof, with a ventilated airspace under the final siding, which is held off the foam sheath with 1/2 or 3/4 pine lath (providing the airspace).

The continuous sheath stops heat transfer in a remarkable way... You are trying to keep it out - I am trying to keep it in... But the same principles apply.

I am really thinking about planting my corn up against the house on the south side - That's the south facing eave side, and I can't get anything to stay there - Bushes get destroyed by the ice coming off the roof in the winter... But how cute to plant corn in there.... It grows great in that super heated environment created by the sun bouncing off the house... and it grows tall - 7 feet or so, where in the hottest part of the year, it will have grown tall and thick enough to shade the south wall of the house, making the house inevitably cooler... And I cut it all down in the fall, out of the way of the snow pile that will inevitably come....

That'd be a smart move.

[Joe Wooten]

Aluminum foil glued to the backside of the OSB panels used on the roof will also reduce the heat load on the house. I did this to the house we built in Texas. The attic was at least 10 degrees cooler.