Every day your building loses energy efficiency, with occasional improvement as equipment is serviced. The “drift”, if left unchecked, could be as much as 30 percent of your energy energy consumption. How does this happen?
A 2012 University of British Columbia study (Montgomery, Green & Rogak) considers the energy cost of filtering air through different styles of standard 61cm x 61cm filter over time. According to the authors “Air filters are installed in HVAC systems to reduce particle concentrations in indoor air. The initial reasoning for filter installation was to prevent particulate from depositing on HVAC equipment, such as cooling or heating coils, and reducing system performance.” While air filters reduce particulate deposit, they are not 100 percent effective.
Montgomery et al found annual filtration costs, for a single (61×61 cm) newly installed filter ranging from just over $100 per year, to $847 per year, across different filter styles and required airflows.
The study also found that energy costs can double in little more than a year after new filter installation.
The energy cost was assumed to be $C 0.07 per KwHr.
The authors concluded “if a building operator is interested in reducing the energy consumption of a filtration system it is desirable to install V-type filters and operate the system at the lowest acceptable airflow rate.”