With the continuing volatility of oil and gas prices, two things have become increasingly important to the owners and managers of buildings of all shapes, sizes and locations: energy management and cool roofing. And yet, the two are seldom discussed as related issues. If you ask a building owner or manager about their energy management strategies, chances are they’ll mention a variety of “high-tech” solutions for improving building automation, systems interoperability, and the energy efficiency of their lighting, office equipment, security systems, and the biggest electricity consumer of all – air conditioning. The U.S. Environmental Protection Agency (EPA) estimates that $40 billion is spent annually to air condition commercial buildings, which is one-sixth of all electricity consumed in the United States.
Important as these high-tech solutions are, the enormous energy savings potential from smart “low-tech” roofing decisions are typically regarded as a traditional “building envelope” issue. But smart roofing decisions can reduce annual air conditioning consumption by 10 to 40 percent, depending on location, building design, climate, and other factors. This not only reduces air conditioning loads and utility bills, but can also allow facilities to downsize their air conditioning equipment considerably.
The Cool Roofing Trend
Roofing can contribute to energy efficiency in two ways – proper insulation, and reflective surfaces. Thermal roofing insulation became a major consideration during the oil embargoes of the 1970s. Proper insulation helps keep warm air in during the winter and out during the summer. Insulation needs vary from climate to climate, and most local building codes today mandate minimum roofing R-values – a material’s ability to resist heat flow.
A more recent trend has been the phenomenal growth of “cool roofing” – the use of white or light-colored roof surfaces that reflect solar energy and keep building relatively cooler in summer months. Although the overall market for commercial low-sloped (flat, or nearly flat) roofing has been stagnant in recent years, demand for cool roofing systems has continued to grow strongly. More than just a sensible, long-term, “green” building design solution, cool roofing is considered by many scientists, industry experts, and government officials to be an effective means of addressing critical national energy efficiency and environmental challenges.
In our next installment we will discuss: How Cool Roofing Works.