Field test methods to measure contaminant removal effectiveness of gas phase air filtration equipment - Phase II -

To save energy and comply with the IAQ procedure in ASHRAE Standard 62-1999 or to add protection to occupants and contents in a building, more building owners and facility managers are using gas-phase filtration (GPAFE) in their buildings. However, GPAFE is fraught with questions about changeout schedules, lifetimes, and capture efficiencies, particularly during episodic events. To save money, facility managers try to minimize filter changeout and sometime eliminate the GPAFE filter banks entirely. Facility managers need to truly understand the service life and capture efficiency of GPAFE systems to effectively (both for protection and cost) use this type of filtration in buildings. To meet these needs ASHRAE initiated a research project in two phases: Field Test Methods to Measure Contaminant Removal Effectiveness of Gas Phase Air Filtration Equipment: Phase I, Search of Literature and Prior Art, 791-RP, and Phase II: Field Test Methods to Measure Contaminant Removal Effectiveness of Gas Phase Air Filtration Equipment, 791-RP (1098-TRP). This paper reports on the findings of Phase II, which was charged with the development of a field test method that would provide building managers and maintenance staff with a procedure to determine GPFAE filter removal efficiencies and lifetimes in their buildings and to provide data on the lifetime and removal efficiency of GPAFE filters in a variety of building types. The research
project collected a large quantity of data from six buildings, which indicated that measuring low concentrations of individual VOCs upstream and downstream of the filter bank does not provide information that will allow a building manager to determine the optimum time for GPAFE filters changeout due to the very low levels of individual VOCs and the constantly changing environment. Measuring TVOCs may yield better data, since the level of TVOCs will be at higher concentrations
than any of the individual VOCs. The use of active or passive samples may provide a tool to build up a profile of the general operation of the GPAFE filters in a specific facility; this, with a combination of other data, such as odor complaints or activities, can provide a database of knowledge that will assist facility managers with predicting imminent filter exhaustion and an action point of when to change the GPAFE filters.