On-Site Particle and Gas Filtration Efficiencies of Air Handling Unit Filters in Industrial and Non Industrial Building

AbstractAir handling units are used to provide a mixture of fresh and recycled (recirculated) air to buildings. They include general ventilation filters for the removal of particles and gases in order to protect the components of the air handling units and to provide clean air to occupants. Standardised test methods exist for the laboratory performance assessment of particulate filters - EN 779 (2012) in Europe and ANSI/ASHRAE Standard 52.2 (2007) in USA - and gas phase filters - ANSI/ASHRAE Standard 145.2 (2011) in USA and draft International Standard ISO/FDIS 10121-2 (2012). Test results enable the comparison of filters against each other but they cannot be used to predict their in-situ performances because the laboratory loading pollutants are not necessarily representative of real pollutants. The EUROVENT 4/10 recommendation (2005) describes the measurement of the pressure drop and the filtration efficiency of HVAC filters on site (this may be one filter or a bank of filters depending on the size of t...