By Tom Hanzely
Lighting and heating, ventilation and air conditioning (HVAC) are the two largest uses of energy throughout the commercial building sector. In fact, lighting alone accounts for nearly 35–50 percent of total electricity consumption. Within the building envelope, however, lies the opportunity to reduce the energy being consumed and decrease a building’s overall carbon footprint. Achieving sustainability within the building envelope starts with specifying the right products. Choosing eco-friendly products doesn’t just ensure lower energy costs; it can enhance occupant health and reduce any negative impact on the building itself, as well as the environment. When designing your next building envelope, consider these three strategies for reducing its environmental impact throughout its lifespan.
Compare Insulation Materials
When it comes to insulating your commercial building, not all insulation materials are created equal. Polyiso insulation, for instance, offers the highest R-value per inch of any rigid foam board insulation. R-value pertains to an insulation’s ability to resist heat flow. The greater the R-value, the less a commercial building has to work to keep the interior at a given temperature, thus putting less pressure on the HVAC system and significantly bringing down energy costs. Because polyiso is so thermally efficient, it requires fewer inches of insulation to achieve the same R-value of other, thicker insulation materials. The amount of insulation required for a commercial building envelope will depend on factors such as climate and the type of heating and cooling system.
Unlike other forms of insulation, such as mineral wool, polyiso can be reused and recycled on roofing applications, assuming the material has not acquired significant damage that would impact its overall effectiveness. Polyiso also beats out mineral wool in terms of energy use. Not only does mineral wool have a Global Warming Potential (GWP) that’s 3.5 times higher than polyiso, but it also requires 85 percent more energy to manufacture as well. The average net energy savings of polyiso lies between nine and 44 times the energy required to manufacture, transport and install the material.
Leverage Daylighting in Lieu of Electric Lighting
An estimated $38 billion is spent annually to light commercial buildings across the U.S. One way to bring down that staggering number is to install daylighting skylights to offset electric lighting. Daylighting can contribute to energy savings by naturally illuminating a commercial building’s interior, which decreases total building energy costs by one-third. Additionally, installing electric lighting controls in conjunction with a daylighting strategy can yield even more energy savings by reducing electric lighting loads and associated cooling loads. Electric lighting generates waste heat, which then takes energy to cool down. Simply turning off those electric lights when they’re not needed can allow facilities to take a more eco-friendly approach to day-to-day operations, and reap the energy-saving benefits at the same time.
When considering implementing daylighting systems into a new commercial building or retrofitting daylighting units into existing buildings, certain factors must be taken into consideration. For example, the architect and building owner must determine which spaces throughout the building would benefit most from daylighting. Potential locations for implementing daylighting units are spaces that are most frequently used, where turning off the lights would have the greatest impact on increased energy efficiencies. The type of commercial building is also an important factor within a daylighting strategy and will help determine how many daylighting units are required and where they should be placed. Manufacturing facilities, offices, schools and retail spaces all have different requirements for light quantity.
Consider Climate When Specifying Roofing Membranes
Climate can help determine which roofing membrane is the most sustainable option for a commercial building. Reflective roofs like TPO (thermoplastic polyolefin), for example, can be an effective way of increasing energy efficiency in warm climates. Rather than absorbing the heat from the sun, cool roofs are equipped with reflective properties that minimize solar radiation absorption into the building, which means the HVAC system doesn’t have to work as hard to keep the building cool.
Vegetative roofs can be another eco-friendly alternative for minimizing energy use. Not only do they play a key role in cooling the air around the building by providing shade, they also protect the underlying roof system from the elements. During the winter months, vegetative roofing systems may provide some level of insulation, which may lead to additional energy cost savings. No matter the roofing system that’s installed, scheduling annual roof inspections is recommended in order to maintain optimal roof life and performance and reap its environmentally friendly benefits. This will ensure that no tears or leaks are preventing the insulation or the roofing membrane from being effective.
Selecting insulation with high R-value, implementing daylighting into new or existing commercial building envelopes, and installing roofing membranes based on climate may not only significantly bring down energy costs, but could also reduce a commercial building’s overall impact on the environment.
For more information on polyiso insulation, visit Firestone Building Products at firestonebpco.com.
Thomas M. Hanzely is a national sales manager for Firestone Building Products SkyScape™ Vegetative Roof System. He holds a bachelor’s degree from Northern Illinois University, DeKalb, and a master’s degree from Lake Forest Graduate School of Management, Schaumburg, Ill. Hanzely has 17 years of experience designing, selling and installing vegetative roof systems throughout North America and is an accredited Green Roof Professional and a LEED professional.