Cooling down the roofs by using reflective surfaces can not only help you beat the heat but also lower air-conditioning bills, suggests new research."Our study proves that cool roofs for commercial buildings are a net saver of energy in all climates that use air conditioning during the summer," said Hashem Akbari, Professor at Concordia University in Montreal, Canada and the study's senior author."In cooler climates, installing cool roofs may even prevent buying an air conditioner altogether. Even in non-air-conditioned buildings, cool roofs improve comfort during hot summer days. And in extreme cases, these roofs may even save lives by reducing the risk of heat stroke," Akbari noted.The findings appeared in the journal Energy and Buildings."Our research shows that any improvement to a roof that limits the summertime solar heat gain actually results in energy-cost savings for the building owner, as well as a reduction in the building's overall environmental impact," Akbari said.
For the study, the researchers used modelling software to simulate energy consumption for several prototype office and retail buildings in four cold-climate cities in North America - Anchorage, Milwaukee, Montreal and Toronto.They found that cool roofs for the simulated buildings resulted in annual energy expenditure savings in all municipalities.The research also showed that cool roofs can reduce the peak electric demand of the buildings by up to five watts per square metre."On a large scale, cool roofs can moderate the air temperature surrounding a building, decrease greenhouse gas emissions and mitigate the urban heat island effect," Akbari said
"Put simply, cool roofs cool the globe," he noted.