Previous analyses of the cumulative influence of collected dust, tobacco smoke/tars and particulates generated in kitchen activities on the coefficient of performance (COP) of heat pumps indicated that the particulate-retention efficiency of finned tube coils ranges from 40 to 78%. This retention was experimentally verified, and can lead to significant heat exchange deterioration over the useful service life of a heat pump or air conditioner. This means that significant operating cost savings can be achieved by the use  of high efficiency air cleaners (HEAC) which retain 90 ± 5% of residential particulates to prevent such deterioration.

We expanded the analyses and complementary experimental work to quantify the operating cost savings due to avoidance of cleaning costs and maintenance of high operating COP. Field surveys show that users seldom have their coils cleaned and, therefore, could benefit from a program to maintain coil cleanliness via application of efficient air cleaners. Our results show that this would save from 10 to 25% of averaged operating costs (for each of the assumed 15 years of service life), or from 25 to 55% during the 15th year of operation, for the range of considered climatic arld dust-loading conditions. Lower efficiency air cleaners or filters, retaining e.g. only 20% of the particulates, would only realize about 1/8 of the above savings under otherwise equal conditions. The magnitude of these benefits suggests that means should be developed to credit the seasonal energy performance figures of merit of air conditioners and heat pumps when they are equipped with appropriate air cleaners.

Includes appendix added in 2004.

Units: Dual