Although cool roofing is one of the most significant green technologies today it is not a new concept.
Green roof and cool roof.
Cool roofs reflect sunlight and heat back into the atmosphere while green roofs help absorb the sunlight and heat before it can enter the building.
Moreover some green roofs need maintenance such as regular watering.
By doing this cool roofs allow for a more comfortable and controlled indoor environment.
Both reduce building energy use for heating and or cooling.
While the term cool roof is sometimes used to describe any roofing surface that is cooler than a standard rooftop green certification programs such as leed energy star the u s.
Green roofs are also referred to as eco roofs oikosteges vegetated roofs living roofs greenroofs and vcp h 8 horizontal vegetated complex partitions.
After selecting to use a green roof or cool roof the roofing contractor must look at the pros and cons of each in order to decide which would be best for the property.
Green roofs are ideal for urban buildings with flat or shallow pit roofs and can include anything from basic plant cover to a garden.
Cool roofs reflect solar energy.
Which system or combination of systems is most appropriate for an individual roof will need to be evaluated on a case by case basis.
The term green roof may also be used to indicate roofs that use some form of green technology such as a cool roof a roof with solar thermal collectors or photovoltaic panels.
Using green roofs in cities or other built environments with limited vegetation can moderate the heat island effect particularly during the day.
A cool roof prevents heat absorption by reflecting the sun s heat and then emitting its radiation back into the atmosphere.
Cool roofs are even cheaper than green roofs only costing 0 75 to 1 50 per square foot and a single ply cool roof membrane usually ranges from 1 50 to 3 per square foot according to epa gov.
A green roof or rooftop garden is a vegetative layer grown on a rooftop.
The primary reasons for using this type of roof include managing storm water and enjoying a rooftop open space.
Green roofs use soil and vegetation as living insulation.
Green building council and the department of energy building technology program base their respective cool roof credentials on a roofing material s ability to reflect the sun solar reflectance and release absorbed heat emissivity.