About COOL ROOFS
On typical summer day, a roof
surface can reach temperatures that are
nearly 100°F above the ambient temperature
In contrast, a cool roof remains at
or near the ambient temperature due to the
characteristics of its outer layer. There are
several benefits to keeping a roof’s surface
cooler, including air-conditioning energy
and demand savings, monetary savings,
increased human comfort indoors, and many positive impacts on environmental quality.
Actual benefits of a cool roof
depend on several factors: building type,
HVAC load and climate. Cool roofs
can significantly reduce summer electrical
energy usage translating into immediate monetary
gains for building owners while promoting the Green initiative to reduce atmospheric
pollutants and greenhouse gases.
Commercial and industrial buildings
account for over half of the total
electricity used in California and consume a significant source of electricity during peak periods.
A seamless fluid applied Cool Roof is a cost-effective
method to save energy and reduce demand usage during peak-periods. In addition, a Cool Roof is an excellent compliment to Solar and HVAC.
FACT: A Cool Roof System effectively addresses the building envelope energy consumption and improves the combined efforts of energy saving systems. Cool Roof Systems are eligible for Federal Tax Rebates.
Solar Reflectance & Thermal Emittance
Solar reflective "albedo" surfaces are often thought of as being “bright white”. Traditional roofing materials have a low solar reflectance of 5 to 15 percent, which means they absorb 85 to 95 percent of the energy reaching them instead of reflecting the energy back out to the atmosphere. The coolest roof materials have a high solar reflectance of more than 70 percent, absorbing and transferring to the building 30 percent or less of the energy that reaches them. Traditional roofs easily reach temperatures of 165F during clear, sunny conditions.
While solar reflectance is the most important property in determining a material's contribution to urban heat islands, thermal emittance is also a part of the equation. Any surface exposed to radiant energy will get hotter until it gives off as much heat as it receives (thermal equilibrium). A material's thermal emittance determines how much heat it will radiate, or how readily a surface gives up heat. When exposed to sunlight, a surface with high emittance will reach thermal equilibruim at lower temperatures because the high-emittance surface gives off heat more readily.
