Evaluation of high capacity filters

High capacity HEPA filters have the potential of significant savings in facilities and operating costs. By requiring fewer filters for a given air flow, the cost of a new plenum planned for construction at Rocky Flats could have been reduced by $8,000,000 if these high capacity filters were used. Also, by replacing the current 1000 cfm filters with these new filters in existing plenums, it was estimated that annual savings of about $1,000,000 in energy costs arising from the lowered pressure drop could be achieved. As a result, a program was initiated to determine whether high capacity filters could meet Rocky Flats qualifications imposed on filters used in plenums. Thus far twenty filters have been tested for filtration efficiencies and flow capacities. All had efficiencies which exceeded 99.97%. However, at 1'' w.g. their flow capacities were all below 2000 cfm. Seven filters have been subjected to the Heated Air Test. Of these, only 2 met the Rocky Flats requirement of less than 3% penetration. However the sealants for neither of these filters was self extinguishing as required