The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...ide-emissions/

On Mar 26, 4:03*pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...



I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. X amount of solar
radiation is hitting the earth. Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

wrote:
On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that
cooler pavement and roofs leads to cooler cities and an overall
cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has
to be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...



I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. X amount of solar
radiation is hitting the earth. Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

Nevertheless, it happens. That's one of the issues with global warming. As the
glaciers and polar ice caps melt off, the land/sea under them will absorb heat
currently radiated back into space by the white ice/snow, warming the planet
even more. Roofs could make a similar difference, and that difference would not
be fully expained by air conditioning costs.

Imagine covering roofs with mirrors. Do you think they would radiate energy into
space? If you don't, would you expect someone in space would see the glare if
the reflection were aimed at them? What they see is energy reflected into space.
White paint reflects almost as much energy as a mirror, but not directionally
like a mirror, so less of the reflection might make it to space than a mirror's
reflection.

White paint for the roads - not the slippery kind they use for road markings.
That would be stupid and cause accidents.

On 3/26/2013 4:13 PM, wrote:
I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

Here's an aerial view of Disney's Epcot Center. Notice the white roofs.
Disney knows what the **** they are doing!

http://binged.it/YdDggm

On Tue, 26 Mar 2013 16:03:49 -0400, Metspitzer
wrote:

The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years.

The limiting factor here would be carbon emissions. The idea of white
roofs making the house cooler is half a century old or more.

It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...ide-emissions/

Thanks.

I didn't want a white roof because I was afraid it would look worse
when it got dirty, so my next door n'bor and I replaced our roofs with
light brown. I can tell the difference. Even when the roof fan is
turned off, it no longer gets so hot on the second floor that I can't
go there. It's always moderately comfortable on the second floor (and
less hot than that on the main floor and cool in the basement) (I
only use AC about 10 days a summer, and last summer not at all because
it was broken.)

OTOH, I used to use the attic heat to heat the house the last part of
fall and first part of spring, and the attic doesn't get hot enough to
do that anymore.

In Indianapolis, I used to drive by the home of one of the richest
guys in town, and the new home of his son. Brown asphalt shingles.
By the end of the firs summer, the brown shingles were off and white
shingles were on. This was about 1962. The benefits of a white roof
have been known for a long time.

And check out your car. Why people buy black cars, with black seats
no less, anywhere but the Yukon, escapes me. It takes more AC to
cool them, and unless you use a remote starter, it's like Hell from
the time you get in the car until the AC has finally cooled it off
some. I have a light tan roof, white seats, and a tan steering
wheel. I can get in the car, sit on the seat with short pants on, and
touch the wheel without suffering on the hottest summer day, whether
the convertible top is up or down.

Well, I think your faith in technology to solve our problems is perhaps a bit inflated. You see, it's one thing to paint a roof or roadway white. It's quite another to come up with a white paint for a roof or roadway that won't be slippery when it's wet and that will stand up to decades of direct intense sunlight beating down on it like tar and gravel roofs and asphalt or concrete roadways do.

The reason why they put pea gravel on top of flat roofs is to protect the underlying asphalt and roofing felt membrane from the UV light of the Sun. It's exactly the same reason why shingles are covered with granules. The aggregate's job is to block the intense UV light from the Sun from causing the asphalt (or asphalt shingle) to deteriorate.

I suppose using white-ER pea gravel on roofs would accomplish the same thing as painting the roof. but getting a paint to last as long as asphalt or concrete when exposed to the same conditions as an asphalt or concrete roadway is going to be difficult. For example, could you still run a snow plow or street sweeper over that white paint without wrecking it? How about putting sand down at intersections during the winter? Won't that sand wreck the paint come spring? And, of course, brand new tires are safe because of their deep treads for accomodating water on the road, but those deep treads also collect stones that will chew up white paint on the road way.

And, on top of all of that 2/3 of the Earth's surface is covered by water which you can't do much about, and the vast majority of the land IS NOT covered with flat roofs or roadways. Painting a shingle roof is asking for trouble because then it'd be slippery when it was wet, and you'd have people slipping and falling off sloped roofs all over the place, and it's those sloped roofs that account for most of the roof area in any town or city.

PS: I always get a kick out of looking at pictures taken outdoors in the southern USA cuz the shadows are so short that you have to look twice to even see there's a shadow! I notice that during sporting events broadcast from the southern US too. I also like to see people wearing light fall jackets outdoors in December. No touques, no gloves, no ear muffs, no electrically heated socks, just a light fall jacket. That's why most Canadians look forward to watching the Superbowl if it's held in Florida, Texas or Southern California. The shadows, the clothes the fans are wearing, and of course, the commercials.

Per :
I say it's total BS.

I used to hang out at a beach near the yacht harbor next to the Ilikai
hotel in Waikiki.

For years and years, the parking lot was just plain old dirt - light
brown, somewhat dusty.

Then somebody got the bright idea of paving the parking lot with
blacktop.

It made a huge difference. The parking lot area and adjacent beach went
from being comfortable to being almost unbearably hot without a strong
breeze to mitigate it.

So, unencumbered by any other knowledge, my money's on the white
roofs...
--
Pete Cresswell

Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...ide-emissions/

I think they should paint the roads white, plant more trees and grass.

I was amazed with my only light plane flight over the desert. You could
feel everything, roads, tracks, etc. Bump bump.

Greg

" wrote:
On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...



I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. X amount of solar
radiation is hitting the earth. Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

Color isn't everything. Use reflectivity index. Higher energy cost is also
meaning more energy creation, more heat. The insulation under the roof is
going to be the main factor.

Greg

"(PeteCresswell)" wrote:
Per :
I say it's total BS.

I used to hang out at a beach near the yacht harbor next to the Ilikai
hotel in Waikiki.

For years and years, the parking lot was just plain old dirt - light
brown, somewhat dusty.

Then somebody got the bright idea of paving the parking lot with
blacktop.

It made a huge difference. The parking lot area and adjacent beach went
from being comfortable to being almost unbearably hot without a strong
breeze to mitigate it.

So, unencumbered by any other knowledge, my money's on the white
roofs...

There is also a big difference in artificial grass vs natural.

Driving around the city suburbs, it's often a relief to drive through a
heavy tree area. Seems 15-20 degrees cooler.

Greg

On Tuesday, March 26, 2013 1:13:37 PM UTC-7, wrote:
On Mar 26, 4:03*pm, Metspitzer wrote:

I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying
types and color of roofs on them, fully instrumented the houses,
and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

Was that based on stock white shingles or shingles painted white?
Because surfaces painted white reflect roughly 90% of the sunlight,
while regular white shingles reflect only 10%.

On Tue, 26 Mar 2013 19:39:43 -0700 (PDT),
wrote:

Was that based on stock white shingles or shingles painted white?
Because surfaces painted white reflect roughly 90% of the sunlight,
while regular white shingles reflect only 10%.


Years ago, a flat roof in Florida had a white quartz on them. In the
desert here, I have seen a couple that used white rocks. Strange,
considering the weight of the rock of the roof and the home age.

Sample photo:

http://www.navarroroofing.com/images/rock-roof-redondo-beach.jpg

trees are the answer
the co2 level actally drops during summer in the northern hemisphere due to all the trees
they absorb co2 and store it in the wood
mark

On Tue, 26 Mar 2013 21:00:19 -0700 (PDT), wrote:

trees are the answer
the co2 level actally drops during summer in the northern hemisphere due to all the trees
they absorb co2 and store it in the wood
mark

"Fossils of a species of extinct giant camel have been discovered in
the Canadian High Arctic by researchers from the Canadian Museum of
Nature."

Photo of giant camels and trees (rendition).

Read more at
http://planetsave.com/2013/03/07/extinct-giant-camel-species-discovered-in-the-high-arctic/#T3CE6p2wethuo4Tx.99

Must be that global warming thing.

The difference between light reflecting off a mirror and light reflecting off a white roof is the difference between "specular" reflection and "diffuse" reflection.



Here's an example of "specular" reflection (off the cold calm water of Icy Bay, Alaska).

On Mar 26, 8:13*pm, "
wrote:
On Mar 26, 4:03*pm, Metspitzer wrote:









The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...

I say it's total BS. *The best study I saw on roof color was
done in FL. *They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. * And that was the energy usage with
the houses unoccupied. *They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. *Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. *X amount of solar
radiation is hitting the earth. *Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

The last bit about reflecting heat back into space is true.
But because roofs are so small the effect is insignificant.
http://en.wikipedia.org/wiki/Albedo#...albedo_effects
http://en.wikipedia.org/wiki/Asian_b...ng_and_dimming

On Mar 26, 8:13*pm, "
wrote:
On Mar 26, 4:03*pm, Metspitzer wrote:









The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...

I say it's total BS. *The best study I saw on roof color was
done in FL. *They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. * And that was the energy usage with
the houses unoccupied. *They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. *Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. *X amount of solar
radiation is hitting the earth. *Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

You can easily tell the difference with white cars and black ones in
the sun.

(PeteCresswell) wrote:
Per :
I say it's total BS.

I used to hang out at a beach near the yacht harbor next to the Ilikai
hotel in Waikiki.

For years and years, the parking lot was just plain old dirt - light
brown, somewhat dusty.

Then somebody got the bright idea of paving the parking lot with
blacktop.

It made a huge difference. The parking lot area and adjacent beach
went from being comfortable to being almost unbearably hot without a
strong breeze to mitigate it.


There used to be a nice breeze. Until they built the Ilikai which blocked
the trades. Ala wai Harbor was much more comfortable before the Ilikai.
For that matter, all of Honolulu was much more pleasant pre-high rise.


--

dadiOH
____________________________

Winters getting colder? Tired of the rat race?
Taxes out of hand? Maybe just ready for a change?
Check it out... http://www.floridaloghouse.net

On Mar 26, 5:39*pm, "Bob F" wrote:
wrote:
On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that
cooler pavement and roofs leads to cooler cities and an overall
cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has
to be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-....

I say it's total BS. *The best study I saw on roof color was
done in FL. *They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. * And that was the energy usage with
the houses unoccupied. *They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. *Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. *X amount of solar
radiation is hitting the earth. *Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

Nevertheless, it happens. That's one of the issues with global warming. As the
glaciers and polar ice caps melt off, the land/sea under them will absorb heat
currently radiated back into space by the white ice/snow, warming the planet
even more. Roofs could make a similar difference, and that difference would not
be fully expained by air conditioning costs.

Imagine covering roofs with mirrors. Do you think they would radiate energy into
space? If you don't, would you expect someone in space would see the glare if
the reflection were aimed at them? What they see is energy reflected into space.
White paint reflects almost as much energy as a mirror, but not directionally
like a mirror, so less of the reflection might make it to space than a mirror's
reflection.

White paint for the roads - not the slippery kind they use for road markings.
That would be stupid and cause accidents.- Hide quoted text -

- Show quoted text -

Then explain why when the experiment was actually done in FL,
using white shingles vs black, it only made a few percentage
points difference in AC energy usage for occupied homes.
And then factor in that the percentage of the earth's surface
that is covered by roofs is negligible compared to the total
surface.

Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...ide-emissions/


Igloos are built with white roofs and they remain very cool inside.
:-)

--
Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeros after @

On 3/26/2013 4:13 PM, wrote:
On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...



I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. X amount of solar
radiation is hitting the earth. Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.


Maybe thats what Limbagh told you but reradiation into space is an
actual physical phenomena.

http://earthobservatory.nasa.gov/Fea...ance/page6.php

Someone should try black roof igloo. I propose a government study. about
$5.5 million for start, and cost over runs and all. End up being about 20
million by the end of the year.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"willshak" wrote in message
...

Igloos are built with white roofs and they remain very cool inside.
:-)

--
Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeros after @

On Tue, 26 Mar 2013 13:13:37 -0700 (PDT), "
wrote:

On Mar 26, 4:03*pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...



I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. X amount of solar
radiation is hitting the earth. Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.


I've seen many model homes around Houston boasting energy saving
features and they don't have white roofs so I think that proves you
right. Our typical summer days are 95F but two or so years ago, we
often had 102F summer days.

On 3/26/2013 3:13 PM, wrote:
On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...



I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

Your recollection of the study's findings is not completely correct.
You're right that in its initial testing of unoccupied homes, it found
an approximate 10% energy savings using a white roof. But it also
found that while occupying the homes increased energy usage overall,
there was no change to the amount saved by the lighter roofs:

"Additional monitoring took place over a month long period with the
homes occupied, but the thermostat set points were kept exactly the
same as in the unoccupied monitoring period. Although average cooling
energy use rose by 36%, analysis indicated no decrease to savings or
demand reduction from the highly reflective roofing systems. The added
heat gains from appliances and people increase cooling system
run-time, with longer periods for the duct system to exchange heat to
the often hot attic space."

And the study's conclusion:

"In summary, this evaluation strongly confirms the energy-saving
benefits of using more reflective roofing systems in Florida.
Selection of colors with higher solar reflectance will result in
tangible cooling energy savings for customers. This is particularly
true for roofing materials such as tile and metal which are currently
available with solar reflectances of 65%-75%. The selection of
reflective roofing systems represents one of the most significant
energy-saving options available to homeowners and builders. Such
systems also strongly reduce the cooling demand during utility
coincident peak periods and may be among the most effective methods
for controlling demand."

http://www.mcelroymetal.com/content/...ight_Study.pdf

On Mar 27, 8:03*am, George wrote:
On 3/26/2013 4:13 PM, wrote:





On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-....

I say it's total BS. *The best study I saw on roof color was
done in FL. *They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. * And that was the energy usage with
the houses unoccupied. *They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. *Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. *X amount of solar
radiation is hitting the earth. *Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

Maybe thats what Limbagh told you but reradiation into space is an
actual physical phenomena.

http://earthobservatory.nasa.gov/Fea...nce/page6.php- Hide quoted text -

- Show quoted text -

Figures someone would drag Limbaugh into the mix. Does
Rush write and publish Discover Magazine and/or the
cited studies?


https://blogs.discovermagazine.com/8...lobal-warming/

On Mar 27, 9:16*am, Doug wrote:
On Tue, 26 Mar 2013 13:13:37 -0700 (PDT), "





wrote:
On Mar 26, 4:03*pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-....

I say it's total BS. *The best study I saw on roof color was
done in FL. *They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. * And that was the energy usage with
the houses unoccupied. *They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. *Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. *X amount of solar
radiation is hitting the earth. *Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

I've seen many model homes around Houston boasting energy saving
features and they don't have white roofs so I think that proves you
right. *Our typical summer days are 95F but two or so years ago, we
often had 102F summer days.- Hide quoted text -

- Show quoted text -


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.

http://www.fsec.ucf.edu/en/publicati...es/roofing.pdf


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......

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

On Wed, 27 Mar 2013 08:10:21 -0700 (PDT), wrote:

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


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 grin ?

On Tue, 26 Mar 2013 18:24:21 -0400, micky
wrote:

On Tue, 26 Mar 2013 16:03:49 -0400, Metspitzer
wrote:

The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years.

The limiting factor here would be carbon emissions. The idea of white
roofs making the house cooler is half a century old or more.

It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...ide-emissions/

Thanks.

I didn't want a white roof because I was afraid it would look worse
when it got dirty, so my next door n'bor and I replaced our roofs with
light brown. I can tell the difference. Even when the roof fan is
turned off, it no longer gets so hot on the second floor that I can't
go there. It's always moderately comfortable on the second floor (and
less hot than that on the main floor and cool in the basement) (I
only use AC about 10 days a summer, and last summer not at all because
it was broken.)

OTOH, I used to use the attic heat to heat the house the last part of
fall and first part of spring, and the attic doesn't get hot enough to
do that anymore.

In Indianapolis, I used to drive by the home of one of the richest
guys in town, and the new home of his son. Brown asphalt shingles.
By the end of the firs summer, the brown shingles were off and white
shingles were on. This was about 1962. The benefits of a white roof
have been known for a long time.


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.

On Wed, 27 Mar 2013 09:06:46 -0400, "Stormin Mormon"
wrote:

Someone should try black roof igloo. I propose a government study. about
$5.5 million for start, and cost over runs and all. End up being about 20
million by the end of the year.

Christopher A. Young
Learn more about Jesus
www.lds.org
.



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

On 3/27/2013 8:55 AM, Doug wrote:
On Wed, 27 Mar 2013 08:10:21 -0700 (PDT), wrote:

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


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 grin ?


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

wrote:
On Mar 26, 5:39 pm, "Bob F" wrote:
wrote:
On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly
simple and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that
cooler pavement and roofs leads to cooler cities and an overall
cooler world.

Since buildings with white roofs reflect far more sun than those
with black roofs, these buildings stay cooler. Less air
conditioning has to be used, lowering the overall energy required
to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed
by clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by
the Energy Department, the federal government hopes to exemplify
the benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...

I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. X amount of solar
radiation is hitting the earth. Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

Nevertheless, it happens. That's one of the issues with global
warming. As the glaciers and polar ice caps melt off, the land/sea
under them will absorb heat currently radiated back into space by
the white ice/snow, warming the planet even more. Roofs could make a
similar difference, and that difference would not be fully expained
by air conditioning costs.

Imagine covering roofs with mirrors. Do you think they would radiate
energy into space? If you don't, would you expect someone in space
would see the glare if the reflection were aimed at them? What they
see is energy reflected into space. White paint reflects almost as
much energy as a mirror, but not directionally like a mirror, so
less of the reflection might make it to space than a mirror's
reflection.

White paint for the roads - not the slippery kind they use for road
markings. That would be stupid and cause accidents.- Hide quoted
text -

- Show quoted text -

Then explain why when the experiment was actually done in FL,
using white shingles vs black, it only made a few percentage
points difference in AC energy usage for occupied homes.
And then factor in that the percentage of the earth's surface
that is covered by roofs is negligible compared to the total
surface.

You are talking about A/C power consumption. The article was talking about heat
released to the atmosphere or reflected through it to space.

The "experiment" looked only at the energy consumed by the A/C in the house, not
the heat released to the atmosphere above the house. Insulation alone could
account for why the A/C was not that affected, but would have no effect on the
atmospheric temp rise.

"willshak" wrote in message
...

Igloos are built with white roofs and they remain very cool inside.
:-)

Stormin Mormon wrote:
Someone should try black roof igloo. I propose a government study.
about $5.5 million for start, and cost over runs and all. End up
being about 20 million by the end of the year.

Christopher A. Young
Learn more about Jesus
www.lds.org
.


Black roof igloos melt very quickly, which proves the origional point.

"Bob F" wrote:
wrote:
On Mar 26, 5:39 pm, "Bob F" wrote:
wrote:
On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly
simple and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that
cooler pavement and roofs leads to cooler cities and an overall
cooler world.

Since buildings with white roofs reflect far more sun than those
with black roofs, these buildings stay cooler. Less air
conditioning has to be used, lowering the overall energy required
to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed
by clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by
the Energy Department, the federal government hopes to exemplify
the benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...

I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. X amount of solar
radiation is hitting the earth. Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

Nevertheless, it happens. That's one of the issues with global
warming. As the glaciers and polar ice caps melt off, the land/sea
under them will absorb heat currently radiated back into space by
the white ice/snow, warming the planet even more. Roofs could make a
similar difference, and that difference would not be fully expained
by air conditioning costs.

Imagine covering roofs with mirrors. Do you think they would radiate
energy into space? If you don't, would you expect someone in space
would see the glare if the reflection were aimed at them? What they
see is energy reflected into space. White paint reflects almost as
much energy as a mirror, but not directionally like a mirror, so
less of the reflection might make it to space than a mirror's
reflection.

White paint for the roads - not the slippery kind they use for road
markings. That would be stupid and cause accidents.- Hide quoted
text -

- Show quoted text -

Then explain why when the experiment was actually done in FL,
using white shingles vs black, it only made a few percentage
points difference in AC energy usage for occupied homes.
And then factor in that the percentage of the earth's surface
that is covered by roofs is negligible compared to the total
surface.

You are talking about A/C power consumption. The article was talking about heat
released to the atmosphere or reflected through it to space.

The "experiment" looked only at the energy consumed by the A/C in the house, not
the heat released to the atmosphere above the house. Insulation alone could
account for why the A/C was not that affected, but would have no effect on the
atmospheric temp rise.

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

Greg

Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A


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

Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.


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

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.

On 3/27/2013 9:42 AM, wrote:
On Mar 27, 8:03 am, George wrote:
On 3/26/2013 4:13 PM, wrote:





On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-...

I say it's total BS. The best study I saw on roof color was
done in FL. They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. And that was the energy usage with
the houses unoccupied. They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. X amount of solar
radiation is hitting the earth. Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

Maybe thats what Limbagh told you but reradiation into space is an
actual physical phenomena.

http://earthobservatory.nasa.gov/Fea...nce/page6.php- Hide quoted text -

- Show quoted text -

Figures someone would drag Limbaugh into the mix. Does
Rush write and publish Discover Magazine and/or the
cited studies?


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



https://blogs.discovermagazine.com/8...lobal-warming/

On 3/28/2013 6:07 AM, HeyBub wrote:
Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.


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

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.


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

"Oren" wrote in message
news
On Tue, 26 Mar 2013 19:39:43 -0700 (PDT),
wrote:

Was that based on stock white shingles or shingles painted white?
Because surfaces painted white reflect roughly 90% of the sunlight,
while regular white shingles reflect only 10%.


Years ago, a flat roof in Florida had a white quartz on them. In the
desert here, I have seen a couple that used white rocks. Strange,
considering the weight of the rock of the roof and the home age.

Sample photo:

http://www.navarroroofing.com/images/rock-roof-redondo-beach.jpg



A quartz rock is really not that heavy, about 150 # per cubic foot
So small 1/8"- 1/4 quartz crystal, an inch think would weigh about 12# per
square foot.
Not that heavy at all.

On Mar 28, 9:40*am, George wrote:
On 3/27/2013 9:42 AM, wrote:





On Mar 27, 8:03 am, George wrote:
On 3/26/2013 4:13 PM, wrote:

On Mar 26, 4:03 pm, Metspitzer wrote:
The idea of painting roads and rooftops white in order to combat
carbon emissions has been around for years. It is surprisingly simple
and effective and yet has not been implemented much.

A study at the Lawrence Berkeley National Laboratory found that cooler
pavement and roofs leads to cooler cities and an overall cooler world.

Since buildings with white roofs reflect far more sun than those with
black roofs, these buildings stay cooler. Less air conditioning has to
be used, lowering the overall energy required to run the building.

Also buildings with black roofs heat the space below them and this
heat is carried spread by the wind. This raises the ambient air
temperature in what is known as the urban heat island effect. Black
roofs also radiate energy back into the atmosphere to be absorbed by
clouds. This heat is then trapped by the greenhouse effect.

As such, white roofs is one of the quickest and most cost-effective
ways to reduce our carbon emissions. In an initiative launched by the
Energy Department, the federal government hopes to exemplify the
benefits by using these light roofs on their buildings.

http://newscenter.lbl.gov/news-relea...-roofs-offset-....

I say it's total BS. *The best study I saw on roof color was
done in FL. *They took a bunch of identical houses, put varying types
and color of roofs on them, fully instrumented
the houses, and measured during AC season.

The conclusion was that if you had a shingle roof, it made
about a 10% difference in energy usage if you had a black
rood or a white roof. * And that was the energy usage with
the houses unoccupied. *They did another test when they
were occupied and the energy usage difference dropped to
just a few percent. *Which makes sense, because when
occupied the energy usage is going to be higher, because
people are opening door, turning on TVs, cooking, etc.

It would also seem to me that it's junk science to suggest
that lighter roofs lead to a cooler world. *X amount of solar
radiation is hitting the earth. *Almost all of it is going to go
into heating it.
So, it's hard to believe that because something is white
that radiation is going back from earth to outer space.

Maybe thats what Limbagh told you but reradiation into space is an
actual physical phenomena.

http://earthobservatory.nasa.gov/Fea...page6.php-Hide quoted text -

- Show quoted text -

Figures someone would drag Limbaugh into the mix. *Does
Rush write and publish Discover Magazine and/or the
cited studies?

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





https://blogs.discovermagazine.com/8...-roofs-may...- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show 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?