Okay, so you installed a cool roofing system, but since the building already had so much insulation you haven’t noticed any energy savings. What’s the point?
True. High reflectivity is a key characteristic that helps keep buildings cooler and can reduce energy usage. As much as 40% less cooling energy may be needed for buildings that have highly-reflective roofs. But even if a building is very well insulated, here are some other valuable benefits from cool roofing:
Insulation can be 25%-50% more effective
Studies have shown that extremely high temperatures reduce the effective R-value of the most widely used types of insulation (Leonard & Leonard, 2005). Cooler surfaces help preserve and keep rooftop insulation materials cooler.
HVAC equipment can operate more efficiently
Inlet air temperatures can be 5-15 degrees cooler 30 inches above a cool roofing surface compared to a black surface. Most rooftop HVAC units are designed with efficiency ratings evaluated at 95ºF (York International, 2005); rooftop temperatures on a black surface can reach 160ºF or higher, meaning that HVAC units will not operate at peak efficiency.
Substrate deterioration may be slowed by as much as 75%
Ultraviolet and infrared radiation and moisture penetration accelerate substrate deterioration. A cool roofing system will reflect this radiation and help protect the substrate (Kirn et. Al., 1994).
Ambient interior temperatures can be up to 20ºF cooler than outside
Studies of worker performance with machine operation and high physical activity reveal that productivity drops 10% at 84ºF and 38% at 95ºF (Schweisheimer, W., 1962). So even if a building is not air conditioned occupants will still notice improved comfort on hot days.
Originally posted by Duro-Last Roofing and re-posted by DK Haney Roofing.
