This is part of a continuing series of articles on simple, inexpensive energy saving tips to implement now that will produce real, measureable, quick energy savings, monetary gains, and greenhouse gas (GHG) emission reductions. These are suggestions that will not “put out” your staff, still result in real energy gains, and make you look like a hero.
Turn your roof into a “Cool Roof”
Cool roofs are roofs that reflect and absorb less of many kinds of solar radiation, such as visible, infrared, and ultraviolet wavelengths. Common roofs have a high thermal emittance, allowing the heat energy from this radiation to enter the building, causing an additional heating load for your air conditioning system. Besides the cost saving benefits of using your AC system less, cool roofs also save money by extending the life of your roof. Summer temperatures on black roofs can reach 150°F or more. Cool roofs reduce this peak temperature by as much as 50°F, reducing the “heat island” effect on the roof which can cause premature damage to your roof and structures on it.
A University of Central Florida study showed a strip mall’s cool roof caused average electricity savings of about 25 percent (pdf). As important, the mall experienced a significant decrease in peak demand during the summer months, as well. Many utilities levy additional, steep charges for high summer peak demand and some offer incentives to reduce this. Cooling your roof is a low cost approach to reduce total electricity usage and peak demand.
These benefits can be easily achieved by merely painting your black roof a light color. It does not have to be white; silver or light blue are popular colors that result in positive effects. More manufacturers offer light-color roofing materials these days.
Of course, by not allowing heat to enter a building, cool roofs may cause your boiler to combust a little more fuel in the winter to heat occupants for comfort. Thus, overall cool roof cost savings will vary based on local climate. Several studies indicate that unless the building is located in a northern region of severe winters, most buildings will receive an overall economic benefit from installing a cool roof. According to the UCF study, the ROI was about 9 years. So, while you may not want to convert an otherwise good roof to a cool one now, if a roof needs replacement anyway, request cool roof materials.
Remember, installing a new cool roof is not the end. Like many other new technologies, proper maintenance is important or else energy savings of cool roofs will drop over time.
Marc Karell is the owner of Climate Change & Environmental Services. CCES can assist you with the technical details of: your emissions inventory; your air permitting status; and whether your facility is subject to air rules such as Title V and/or PSD. We can help you navigate through their complex processes. Read more useful material in the company’s blog: www.CCESworld.com/blog. CCES has experience in performing site-specific energy audits and recommending proven strategies and technologies to reduce your facility’s energy usage, saving you money with a good ROI and without inconveniencing your staff. See our website: www.CCESworld.com and contact us at karell@CCESworld.com.