4 ms·
What we really need is white paint in the summer, black paint in the winter - reversible roofs, if you will. That said, in the desert southwest and many places
by ebiester 6y ago
What we really need is white paint in the summer, black paint in the winter - reversible roofs, if you will.
That said, in the desert southwest and many places in the world, white roofs are common. I wish it were more common in the southeast...
- fullstop 6y agoCouldn't solar panels be used to achieve both benefits?
- beauzero 6y agoIf you look at old architecture in rural Georgia and Alabama. Houses are on rocks raised above the ground (air circulates underneath), 10 ft ceilings, a huge attic fan to pull cool air in in the evening, tall trees planted next to the house for shade (we have 4 pecan trees), and reflective tin roofs (if still shiny). This helped significantly to cooling in the summer. Winters aren't cold enough to warrant more than a fireplace in the common area. We have an old farm house built in the 1920's...the old original part of the house doesn't get uncomfortable until the temperatures outside get above 100. A newer part of the house with standard 9ft ceilings built in the 70's gets very warm and uncomfortable.
- gerikson 6y agoThe same kind of ideas were present in bungalows in British India and other parts of Asia. In general I think a lot of energy savings can be realized by accommodating buildings to the prevailing climate, and using passive means of heating and cooling.
- quercusa 6y agoWide eaves help as well to keep summer sun off windows and to provide a place for a porch. A gentle rain on a tin roof is a sure ticket to sleep; a strong one not so much. I'd never thought about ceiling height - that makes a lot of sense.
- theluketaylor 6y agoWell designed buildings for passive cooling/heating in the higher latitudes can also take advantage of wide eaves. Since the sun is lower in the sky during winter you can design a home with eaves that block the summer midday intensity but allow sunlight to flood in throughout the winter with some careful calculations and site placement. Houses built to suit their location can slash the amount of energy required to regulate the temperature.
- Tade0 6y agoBlack in the winter would make the building lose heat faster - especially during the night.
- dieortin 6y agoHow so? It would absorb more radiation from the sun. In cold European cities the roofs are traditionally black.
- goodcanadian 6y agoThings that readily absorb energy readily emit it also.
- citrin_ru 6y agoAt winter day is shorter than night and even during the day sun is relatively low so for black roof would likely emit more energy than adsorb.
- throwaway0a5e 6y agoCorrugated material could provide a white surface to the mid-day sun in the summer and a black surface to the mid-day sun in the winter. Of course you'd need to take latitude and roof slope into your calculations but I bet if you made the materials in 10-deg increments you could get something "good enough" for most use cases. Or you could just make the material change color based on temperature. This is all known science but getting it cheap enough to be used as roofing is the trick.
- diggernet 6y agoOh, nice, a lenticular roof. Make it show white from summer sun angle, black from winter sun angle, tile roof images from ground level, and a "Pull Up" sign for aircraft overhead.
- deleted 6y ago[deleted]
- loonster 6y agoI'm really curious about the energy savings that roof mounted solar provides (not including electricity that the panels produce). In the summer, they shade the roof keeping it cooler. In the winter, they provide an additional ventilation area that allows heat to escape without melting snow (thus mitigating risk of ice dams). Even a snow covered solar panel provides a benefit.