White roofs catch on to save energy costs | Hacker News Reader

White roofs catch on to save energy costs

nytimes.com

10 pointsCoryOndrejka16 comments

I don't mean to make fun, but this sentence struck me as funny: "Relying on the centuries-old principle that white objects absorb less heat than dark ones"

As if before those "centuries" light and dark objects absorbed heat differently. :)

In the same manner: Was there ever a time when a human could not figure out that black rocks got hotter than white rocks?

How about making them more reflective and aiming them at New England for a little winter heating help.

A friend who used to live in Florida told me they would put water on the roof in the summer. The evaporation of the water would cool down the roof and house.

My Toyota FJ Cruiser has a white roof and tinted glass, it seems to stay much cooler in the sun than any vehicle I had before.

What you really need is a roof is that is black in the winter and white in the summer.

Well if you want to save big on energy costs and you don't mind your house being quirky an underground home is for you. When you're below the frost line, the underground temperature is 55-57 degrees F, in winter or summer. Plus you get great noise insulation.

http://en.wikipedia.org/wiki/Earth_sheltering

That is totally awesome, thank you for bringing this to my attention.

Maybe someday when I'm rich I will build my house like this - less for the energy efficiency and more because it looks totally badass.

This is an excellent point! Just building an earth bermed home can save a fair bit from improved insulation properties. In the US we have not explored this option nearly enough, in my opinion.

No windows though. Big turn off.

What about skylights?

e-ink roofing?

two sided panels that you flip over make a lot more sense

Removable roofing.

The roof is white, but you put black panels on it for the winter. In the summer, you take them off. Or vice versa.

That would be better, but for most places, there isn't much solar energy coming in during the winter, so they aren't losing much by being white.

Maybe for winters the best would be to use fluid based collectors with coils inside the envelope of the building to skip the energy past the insulation. With a low sun angle you don't need much area of them to capture all the sun and in the summer they would provide shade to a portion of the white roof. Now, if only they were free.

That's kind of irrelevant if you live in an area where winter actually exists, since your roof is automatically white from about December on. :)

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