The cool roofing debate continues

This letter is in response to "Still cool after all these years: White reflective roofs stand up to scientific scrutiny," October 2013 issue, page 38, by Stanley P. Graveline, vice president of technical services for Sika Sarnafil, Canton, Mass.

Carlisle Construction Materials, Carlisle, Pa., a manufacturer of roof insulation and black and white single-ply membranes, agrees wholeheartedly that white membranes can be part of an energy-efficient roof system. In warm, southern climates where the bulk of energy bills come from air conditioning, reflective cool roofs can cut energy bills, decrease stress on the power grid and reduce natural resource consumption.

But in cold, northern climates, building owners typically spend much more on heating than air conditioning. Government data shows heating a building consumes about five times more energy than cooling it. Unfortunately, white roofs often are installed and even mandated in cold-climate regions where they do not deliver major energy benefits, and this can lead to undesirable and unintended consequences.