Developing the right strategy for your building's HVAC air filtration system can contribute to the completion of LEED-EB: O&M credits and prerequisites by improving indoor air quality (IAQ) and energy efficiency. Effective air filtration provides the primary defense for building occupants and HVAC equipment against indoor pollution and plays a significant role in how much energy is consumed to operate the HVAC system. The higher the filter's resistance to air passing through it, the more energy is consumed. The right strategy can net up to 11 LEED points and meet other green building system criteria including reductions in greenhouse gas emissions and waste.
The filter media has the biggest effect on providing clean air, protecting HVAC equipment and minimizing energy consumption. This is because modern mechano-electret filter media provides a lower resistance to airflow while maintaining high-particle capture efficiencies. When the HVAC system fan motor meets with less resistance delivering the required airflow, there's a reduction in the motor's energy consumption, so look for filters that offer a good balance of mechanical efficiency and electret efficiency (via an electrostatic charge). These filters almost always outperform and deliver lower airflow resistance than filters that rely solely on mechanical efficiency.
In addition to switching to an HVAC air filter with a lower resistance to air flow, consider implementing metering devices to measure air distribution, static pressure and ventilation air volumes. Use pressure gauges to measure resistance to airflow to determine the appropriate change out cycle for air filters. Purchase high-capacity pleated filters or mini-pleat v-bank final filters. This extends filter life to reduce change outs and waste streams while minimizing reistance to airflow. Specify filters with the appropriate MERV (Minimum Efficiency Reporting Value) to reduce and/or eliminate particulate and gaseous pollutants found in the building.
Installing MERV 13 or higher air filters and establishing and following a regular schedule for filter change outs also contributes to LEED-EB: O&M credits. In the case of a building alteration or addition, installing MERV 8 filters at each return air grille during construction and replace all filtration media and flush out the space prior to occupancy. For more on LEED - EB: O&M visit www.usgbc.org.