Roof cooling and energy
savings
Alternatives to common roof shingles
Asphalt and fiberglass shingles
Asphalt and fiberglass shingles
absorb most of the solar radiation, and are energy-inefficient
products. A large amount of the unwanted heat in buildings comes
in through the attic and the roof.
If you intend to re-roof your home, or if you are building a new
home,
consider energy-efficient
alternatives to common asphalt and fiberglass shingles.
These alternatives will
decrease the heat transferred into attics and rooms
by several degrees and will save you money and energy (reducing
your air conditioning needs).
Besides, a cool roof can also increase the roof’s life cycle
and reduce urban heat islands (higher
urban temperatures relatively to surrounding countryside, due to
dark and inefficient urban roofs and pavements), which is good for the
environment.
Reflective roofing materials
Reflective roof materials are alternatives to common asphalt
shingles and other dark-colored and traditional materials used in
roofing. These other alternative materials include…
1- some types of metal roofing and tiles with white colors
(clay and cement)
2 – roofing coatings (namely white reflective ones) and roofing
membranes
3 – recycled green products
The color of the roof
Most roofs in America and worldwide are dark-colored, which may
absorb up to 90% of the energy of the sun, causing higher cooling needs
and air conditioning costs.
If you are considering a new roof or a roof remodeling do not
forget the color issue.
Roofs with white and lighted colors provide high energy savings,
namely in hot and mild climates.
See:
Roofing and climate
Roof and insulation
An energy-efficient home needs both reflective roof materials and
a good
insulation in the attic and ceiling. When installing a reflective roof, to attain
maximum energy savings consider also an optimum
level of insulation.
See, for details:
Attic insulation
Roof and ceiling
insulation
Reflective
insulation
Reflective roofs and attic fans
Attic fans are a good and cheap contribution to a cooler attic
and to significant energy savings in air
conditioning bills. In a way, they are an alternative to
reflective roofs, but they do not solve the problem of very high
temperature and have a much more limited scope.
See:
Attic fans basics
Solar attic fans
Solar vs. electric
attic fans
Radiant barriers and roof cooling
To reduce attic temperatures you may
also install a radiant barrier (basically a sheet of aluminum foil)
on the underside of the roof. A correctly installed radiant
barrier can reduce heat gains through ceiling by a quarter, and
is a partial alternative to reflective roofing.
See, for more information on radiant barriers:
Reflective
insulation
Roof cooling and green roofs
A green roof is a roof-top garden: a roof
covered with vegetation planted over a waterproofing layer. Green roofs
are experiencing some popularity in some cities and states, and
are ecological alternatives to both
reflective roofing and insulation of attics and ceilings.
See, for details:
Installing a green roof
Green roofs costs, pros and cons
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