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.
Before and After Installing a Cool Green 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