Yes, you read that right. The benefits of cool roofing in northern climates have been the subject of debate for years, but a consensus is growing that, under specific conditions, even reduced energy savings justify the outlay for cool roof technology.
Most of the factors that influence the decision are the same no matter where you live: the specifics of the local climate over the course of a year, the type of building, the patterns of energy use within it, and certain physical characteristics, like the placement of ducts and the amount of insulation.
Insulation introduces an additional complicating factor: Building codes have significantly increased the amount of insulation required in new commercial construction. The interiors of these buildings experience less temperature variance for cool roofs to mitigate.
In addition, cool roofs continue to mitigate rising temperatures even when that’s not helpful. Researchers have noted an association with small increases in winter energy use in cold areas because cool roofs reflect solar heat that would help warm the building in other locales.
Even after considering all of these counterarguments, cool roofs in cold climates remain worthwhile under most circumstances. The amount of otherwise useful energy that is wasted by reflection in the winter is generally less than the amount of undesirable summer heat for which air conditioning does not have to compensate.
Two factors help to explain this phenomenon. First, several characteristics of winter reduce the inevitable waste: shorter days, less intense sunlight during those shorter days, and relatively frequent cloud cover. Second, cool roofs (unsurprisingly) reflect more energy when there’s more energy to reflect. Therefore, they save the most money during the hottest parts of the hottest days of the year. These times are frequently designated as periods of peak demand by energy providers, during which prices increase in order to encourage those who can to use energy at other times of the day. Cool roofs thus save more money during the hours when higher rates are in effect.
One longstanding argument against the use of cool roofing in northern areas has been undermined by recent developments. Some have argued that many of the benefits of light-colored cool roofing can be provided by a light layer of snow. The standard counterargument is the fact that some regions experience cold winters with very little snowfall. The terms of this debate have been altered by accelerating climate change. Areas formerly characterized by year-round snow cover now experience less snowfall, and some now fully exposed by melts during parts of the year.
In summary, the benefits that cool roofing can provide in colder climates are undeniably less dramatic than the cost savings achievable in warmer regions, but the advantages remain clear and significant. If you own a commercial building, talk to a local roofer to find out what cool roofing can do for you.