Energy Efficient Roofs – Green Roofs
A white, reflective roof can saving you 20% or more on energy costs. Below is a photo showing the difference in temperature between a darker built up roof and a white roof. This picture was taken on the same day on two different sections of the same roof. One side we had just installed a new white roof and a section we were about to replace an old roof. As you can see the difference in temperature is wide. Imagine this on your roof.
The darker the roof and or the more square feet your roof covers the higher the impact when you change to a reflective roof.
There are several options to make this change to your roof, however the most cost effective option if your roof qualifies is a liquid applied roof system or coating. Coating is a seamless membrane, costs 1/2 or less the price of a roof replacement, can be installed in 1/3 the time and the 15-20% energy savings will offset the price. Don’t just take our customer’s word for it read the independent study results as well.
Substituting a weathered cool white roof (solar reflectance 0.55) for a weathered conventional gray roof (solar reflectance 0.20) yielded annually a cooling energy saving per unit conditioned roof area ranging from 3.30 kWh/m2 in Alaska to 7.69 kWh/m2 in Arizona (5.02 kWh/m2 nationwide)…and an energy cost saving ranging from 0.126/m2 in West Virginia to 1.14/m2 in Arizona ( 0.356/m2 nationwide) – Springer science article on 20% savings for businesses with a white roof
According to the EPA a California study found that cool roofs provide an average yearly net savings of almost 50 cents per square foot. – EPA.gov
The government Office of Scientific and Technical Information study shows that coating roofs white reduces summertime average daily air-conditioning electricity use from 2–63% – OSTI.gov study