EXPERIMENTAL INVESTIGATION OF GEARED DOMESTIC REFRIGERATIVE DEHUMIDIFIER PERFORMANCE IN NEW ZEALAND HOUSEHOLD CLIMATES

Small refrigerative dehumidifiers, which are commonly used in New Zealand to reduce household moisture, typically operate in relatively cool environments, outside their optimum performance envelope. This study investigates the potential for improving the low-temperature drying capacity of a domestic dehumidifier fitted with an evaporator economiser. The paper reports performance measurements on a modified domestic dehumidifier which can be operated either geared with an evaporator economiser, or ungeared. An empirical heat pump model, which was calibrated using the ungeared performance data, was also used to compare the two modes. The measured results show a clear improvement in the dehumidification capacity in the geared mode at the higher temperatures tested, but the performance improvement in the lower temperature tests was less than expected from the model. Shortcomings in the trial and in the dehumidifier model are discussed and ways for resolving them identified.