Painting roofs white can actually help lower the temperature of a city

Now it gets interesting. I went looking for the study done in Florida that I read just a month or so ago. I found the same study again, or I should say part of it. The original study that I saw consisted of instrumenting and monitoring the energy usage of 6 side by side houses in FL that were identical except for the roof type and/or color. As I posted earlier, the study showed that on a yearly basis, having a white shingle roof versus a dark grey one resulted in a 10.8% reduction in energy usage.

formatting link

But here is the interesting part. That 10.8% number is with the houses set at 77F and UNOCCUPIED. In the SAME study, when I previously saw it, it also contained a section on the results when the homes were then monitored OCCUPIED, but with the thermostats still set at 77F. And when occupied, the yearly energy savings dropped to just a few percent. The reason for that is obvious. The amount of energy saved by the white roof is going to be the same whether occupied or unoccupied. But when occupied the energy usage overall is going to be higher, due to opening doors, cooking, appliances, etc. So the percent savings of the actual energy usage is going to be a lower percentage.

It's interesting that part is gone. Now why might that be? Maybe it's because it's too real. I'm getting a new roof and was curious about the difference between a grey or black shingle. When I saw that in a real house, in FL of all places, going from dark grey to white only resulted in a few percent savings, I said forget it, the difference between black and grey isn't going to matter. And keep in mind that is for FL. I'm in NJ and in northern climates, what you save in summer is partly offset by increased heating costs in winter......

Reply to
trader4
Loading thread data ...

there was some show on TV

there's a city somewhere in the midwest[?] that plants real green stuff on their rooftops, and they say it has had a big impact

marc

Reply to
21blackswan

When I use to travel to Austin, Texas a couple years ago, going north on I-71, there was a place that I think is some kinda outside lab site for a local college which has solar panels and a small structure with grass growing on the roof. I never stopped there but thought it was interesting what they are trying to do. Do you have to eventually mow the roof ?

Reply to
Doug

When I was a kid, my dad being a carpenter put a white roof on our house (Long Island). I think it was either the only one or one of two in the large neighborhood. It wasn't too white as I recall (I was a youngster more interested in playing than construction then) so I don't think it showed the dirt that much but we moved away before it got to be near the end of its life so I can't say what it looked like then.

Reply to
Doug

Yeah and if they run outa money, just steal it from the SS funds.

Reply to
Doug

in switzerland they grow plants on the roofs, but they let the cows mow them down.

Reply to
chaniarts

It takes a power plant to make that electricity, which makes the atmosphere warmer.

Greg

Reply to
gregz

It's easy to compute what's hot and what's not, and how much can be gained. Just take a look at the Landsat images from space. They started taking image scans of the earth in the mid 70's, with the multi spectrum image scanner. IR temperature of the ground is easy to detect. I think it actually used a rotating mirror to scan as the satellite moved over a hundred miles high looking at earth. Was first called ERTS satellite. environmental resource and technology satellite.

Greg

Reply to
gregz

Could very well be true, but your HOUSE will look like shit!

Soot and other particulates will stand out on a white roof. Look around your neighborhood - do you see any white or light-colored roofs? Well, why not? And for those you DO find that are somewhat less than dark, don't they look ghastly?

Heck, you don't have to look at the roof; look at your very own brick work. Do you think that black mess GREW there? You know, the stuff you have to power-wash off every few years.

Yuck!

A white roof may very well be useful atop a 27-story office building but for a one or two-story residence, forget it.

Reply to
HeyBub

Don't know but your ranting sure sounds like the usual stuff from his groupies who just run with whatever "Rush said".

formatting link

>
Reply to
George

locality. in my neighborhood, every house with a flat roof (about 75% of all houses) is painted white.

Reply to
chaniarts

quoted text -

- Hide quoted text -

And you sound like the typical lib elitist that drags Rush into anything and everything, claims he's said all kinds of things, but actually never listens to him.

Oh, and BTW, a better source for energy that reaches the earth not making it back into space would be Al Gore. He's the one telling us green house gases, caused by man, are trapping all the heat. So, which is it? It's being trapped or you can just reflect it all back into space from the ground?

Reply to
trader4

We should develop a car engine that burns greenhouse gas. That would be a very useful thing. Or, we could develop a car that runs on hot air. Al Gore would make a fortune..

Reply to
Robert

A part of roof restoration or replacement is painting, which instantly adds value to your house and give it character and appeal.The professionals of one the best roof painting Adelaide, Roof Doctors use the latest equipment to perform the services. Painting on the roof will prevent too much water p enetrating your tiles and causing too much moisture build up in your roof. For more details contact at :

formatting link

Reply to
doctorsroof

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.