Lawrence Berkeley National Laboratory Study
Study Proves White PVC Roofing System Saves Money
In a two-year scientific study commissioned by the U.S. Department of Energy (DOE) and the Environmental Protection Agency (EPA), researchers at the Lawrence Berkeley National Laboratory set out to compare two distinct types of roofing systems by monitoring and verifying summertime air conditioning and peak electrical demand at a 100,000 square foot retail establishment in Austin, Texas.
Building temperatures and energy usage were monitored for a period of one year with an existing black rubber EPDM roof. The roof was then replaced with a white, reflective Sarnafil PVC roofing system and the test was run again during the same time of year as the previous test.
|LBNL study results ...|
|Total annual air-conditioning savings from the PVC roofing system were estimated to be $7,200, or 7.2 cents per square foot (based on 2001 pricing). This does not include savings from taxes or other utility charges.|
|The estimated savings over the lifetime of the membrane with the PVC roofing system was calculated to be between $62,000 and $71,000 (based on 2001 pricing). This was calculated using an industry average of 13 years for a single-ply roof membrane. Sika Sarnafil roof systems have been proven to last much longer than this, which would further increase the savings for the store.|
|Additional savings of thousands of dollars could be achieved if the building owner participates in the state’s load curtailment and/or reflective roof rebate programs.|
Analyzing the Data
Scientists from LBNL’s Heat Island Group used advanced collection techniques for recording site-specific weather, temperature and energy consumption data. The monitored input was gathered over a two-year period in a pre- and post-roof retrofit analysis (1999 – 2000).