Modeling the Impacts of Filter Fouling on Energy Consumption

Abstract

The use of higher efficiency particulate air filters in central heating, ventilating, and air-conditioning (HVAC) systems to improve indoor air quality (IAQ) in homes is continuing to increase. However, as filters are loaded with collected particulate matter and dust, the pressure drop will increase and lead to a variety of direct and indirect energy impacts. The magnitude of energy impacts on fouled, or dirty, filters is not yet known. Therefore, this paper explores the energy impacts of fouled filters on new energy-efficiency homes in multiple climates around the United States by performing whole building energy simulations using BEopt and EnergyPlus. Relevant inputs include filter pressure drop, total pressure drop, HVAC airflow rate, fan efficiency, heating and cooling nominal capacity, and rated airflow rate. The results indicate that annual energy consumption generally increases for permanent split capacitor (PSC) and electronically commutated motor (ECM) fans as the filter gets loaded or dirty over time, although the energy impacts are smaller for ECMs.