Roofing Products

What is the ENERGY STAR program?

EPA’s ENERGY STAR program is familiar to many homeowners who may have noticed the unique label on appliances and electronic equipment. The ENERGY STAR program also has roof products criteria for cool roof products.  A roof that meets the ENERGY STAR performance requirements is considered one that is cool and helps to reduce urban heat island effects.  The criteria for a labeled roof in the new version 2.0 of ENERGY STAR, starting in October 1, 2007 are:

•    For steep slope applications (greater than 2:12 pitch):  initial minimum solar reflectance of 0.25, and 3-year aged minimum solar reflectance of 0.15.
•    For low slope applications (2:12 or less pitch):  initial minimum solar reflectance of 0.65 and 3-year aged minimum solar reflectance of 0.50.

All colors of cool Kynar 500 based prepainted metal roof products meet these criteria and become labeled ENERY STAR products and qualify for a $500 dollar tax credit that expires December 31, 2011.

What is a cool roof and how does it work?
Cool roofing is defined differently by unique performance criteria established in different codes, standards, and incentive programs.  In general, a cool roof is one that does not absorb solar energy which allows the surface temperature to remain lower. During the daylight hours, a roof is constantly subjected to solar energy striking its surface.  The term “Solar Reflectance” is a measure of the amount of that solar energy that is immediately reflected from the surface. It is not reflected heat, but reflected electromagnetic energy from the sun.  Solar reflectance is reported as a decimal (0 – 1.00) or as a percentage (0-100%).  The solar energy that is not reflected away from the surface is absorbed into the outer surface of the roof product and is converted into heat. The heat can be removed by convection as air flows over the surface, or by conduction through the roof material into the sheathing below. The energy that is left can also be re-emitted to the night sky in the form of infrared energy. That re-emitted energy is referred to as thermal emittance, which is also expressed as a decimal (0 – 1.00) or as a percentage (0-100%).

A cool Kynar 500 based prepainted metal roof can be formulated with special inorganic cool pigments which boost the solar reflectance by reflecting more infrared solar energy. These pigments do not affect the visible color, so that darker colors can now perform like lighter colors in terms of their solar reflectance values. A cool metal roof with high solar reflectance and high thermal emittance would have a lower surface temperature as compared to a roof with low reflectance and low emittance. In the case of a cool metal roof, a lower surface temperature translates into less heat gain into the attic space or living space below the roof.  The result is a cooler building and lower cooling/heating energy usage

The foundation and by far the most important element in the system is the roof. It is the base upon which all other elements are attached. To be cost effective the labor involved in mounting solar and wind equipment should only be done once. Asphalt roofing, no matter what shingle you pick, is a temporary roofing material and needs to be replaced thereby removing and remounting the equipment numerous times.  You would have to remove and replace the equipment four or five times to replace the shingles before you equal the life expectancy of our metal roof. 

Next is the fact that traditional asphalt offers no energy savings at all. When stacked up against our roof with an energy savings potential of up to 40% there is only one financially sound choice. The cost of four or five asphalt roofs for an average home can run as high as $35,000 to $40,000 dollars with no energy savings. In contrast our energy savings roofing system with Kynar 500 coating can save the average home as much as $40,000 in energy costs over the same period. That’s a whopping $80,000 swing! And we have not even calculated the increased costs of energy and shingles over the next 40 plus years! Just for fun estimate an annual cost increase of just 4% and see what happens to the numbers!

Why is Kynar 500 the best choice for a cool metal roof coating?

The proven durability of Kynar 500 resin type paint systems allows for stable color and film integrity over decades of exposure. This durability is also seen in the retained amount of initial solar reflectance. Thus, paint systems based on the Kynar 500 resin have a surface that does not retain dirt, remains cool,  and retains its original color better than any other resin type.

In the design and performance of a building, the owner wants to know that the initial energy cost savings projections are maintained over the life of the roof. Most other roof types have been documented to lose some percentage of their initial solar reflectance due to dirt pick up and overall degradation from the weather. In those cases, the aged performance of these cool roofs is far from what the building experiences in the early years.  The strong performance of Kynar 500 based paint system which is maintained over time is especially apparent in the retention of the initial solar reflectance of cool Kynar 500 based prepainted paint systems. In research conducted by Oak Ridge National Laboratory on behalf of the Cool Metal Roofing Coalition Kynar 500 based prepainted metal test panels exposed in South Florida were found to retain 95% of their original solar reflectance over more than 30 years. Typically, dirt pick-up and retention is responsible for many roof products’ solar reflectance dropping over time. This is also true for some conventional resins used for prepainted metal roofing.  However, Kynar 500 based prepainted metal roofing readily sheds dirt and does not promote the formation of algae or other microbial growth on the surface which could lower the solar reflectance.

In the Metal Construction Association’s roofing certification program, the Kynar 500 based paint systems achieve the highest performance certification – Premium. No other prepainted metal roofing product has the high levels of gloss retention, color and chalk performance that are required for a MCA Certified Premium Painted product. So again, the aesthetic appeal of using a Kynar 500 based prepainted cool metal roof is second to none when a building owner is considering what type of cool metal roof to specify. ARKEMA’s research indicates that there are many reasons why Kynar 500 based paint systems are the product of choice for cool roofing applications.  The most weatherable coatings for metal roofing are based on polyvinylidene difluoride resin technology.  These resins have superior resistance to photo-chemical degradation. They maintain their gloss and color better than any other resin technologies used in today’s exterior paint systems used in the metal roofing industry.  Actual exposure of panels in South Florida’s harsh climate after nearly 40 years substantiates the outstanding performance of the Kynar 500 resin.