Tag Archives: thermal emittance

Cool Roof Systems

Cool roofs are roofing systems creating higher solar reflectance and thermal emittance than standard roofing products. Solar reflectance is a process where a roof reflects the sun’s UV and infrared rays, reducing the total amount of heat transferred to a building or home. Thermal emittance is a roof’s ability to radiate absorbed and non-reflected solar energy. Dark colored and more standard roofs can reach temperatures of up to 150°F in summer sun, while a cool roof in similar conditions can stay more than 50 degrees cooler. Cool roofs also can enhance a roof’s durability, reduce cooling costs, and reduce urban heat island effect (when built-up areas are hotter than surrounding rural areas).

Cool roofs are an important part of sustainable building. Hansen Pole Buildings offers steel roofing and siding panels in cool roof colors, created with highly reflective paint to help metal panels reflect sunlight and absorb less heat. It’s important to note trapped heat in a roofing system can cause damage and require roofs to be replaced more often. Cool roofs can extend lifespan of a roof, especially in warmer climates, and reduce energy costs.

Cool Roofing Rating Council (CRRC), was established in 1998 to create credible methods for evaluating and labeling solar reflectance and thermal emittance of roofing products. This method has become an accepted part of LEED applications and known as Cool Roof Systems. The CRRC uses the Solar Reflectance Index to rate Cool Roof Systems.  

There are tons of benefits for installing a cool roof system. Some benefits include:

  • Reduce Energy Use — By decreasing air conditioning needs, cool roofs are able to reduce a single home’s energy usage. 
  • Decrease Roof Temperature & Increase Roof Lifetime — By lowering temperature, cool roofs can extend the life of a roofing system even further.
  • Improve Indoor Conditions — Cool roofs can improve conditions and comfort of areas and rooms indoors not being air conditioned, like garages and covered patios
  • Aid Climate Change — Since cool roofs directly reduce greenhouse gas emissions by conserving electricity, they help lower CO2 emissions from power plants. 

According to the U.S. Green Building Council, Solar Reflectance Index (SRI) is a measure of a constructed surface’s ability to stay cool in the sun by reflecting solar radiation and emitting thermal radiation. This index ranges from 0 to 100, with a standard black surface having an initial SRI of 0 and a standard white surface having an initial SRI of 100. 

Hansen Pole Buildings is proud to offer our clients products having earned our government’s ENERGY STAR label. Energy Star is a U.S. Environmental Protection Agency (EPA) program helping businesses and individuals save money and protect our climate through superior energy efficiency. 

Homeowners who install an ENERGY STAR compliant pre-painted metal roof can also meet requirements for additional tax credits.