Advanced Low-Emissivity Glasses Provide Significant Energy Savings in Commercial Buildings

At the Façade Tectonics #7 conference, PPG highlighted the results from a study demonstrating the energy savings achieved through the usage of advanced low-emissivity glasses.

Façade Tectonics #7 was held on Dec. 2 in the School of Architecture at the University of Southern California. Over 200 enthusiasts - architects, designers and doctoral students attended the conference. The national architectural manager for the flat glass construction market team at PPG Industries, Chuck McMullen, cited the energy savings achieved in a prototype, eight-storied, window-walled, office building in Los Angeles. Specifying low-emissivity, double-silver-coated glass will help achieve energy savings of over $37,000 annually, when used instead of the spectrally selective tinted glass. Specifying low-emissivity, triple-silver-coated glass will increase the potential savings to $75,728, he said.

Triple-silver-coating will reduce the annual electricity usage related to heating and cooling of the building by approximately 500 kWh. It also reduces carbon emissions by approximately 500 t annually, which will be equivalent to the amount of greenhouse gases emitted by 90 automobiles in a year. The savings derived from equipment and energy costs will repay the costs of installing these glasses within six months, in most scenarios. The glass also reduces natural gas consumption in the building by 27%.

In his presentation titled, “Energy Efficient Glazing: Commercial Glass Selection Criteria,” McMullen highlighted the benefits of lower costs due to lesser heating, air conditioning equipment and ventilation costs. The advanced low-e glass blocks solar heat, thus reducing the need for cooling. When low-e, double-silver-coated glass was used instead of the spectrally selective tinted glass for glazing of the prototype building, the initial expenses for HVAC equipment was reduced by $210,000. And when low-e, triple-silver-coated was used, the savings nearly doubled to $418,000.