Fluid flow modulation in a domestic refrigerative dehumidifier with air-side gearing

Abstract

Small refrigerative dehumidifiers have shown energy efficiency improvements when operating with air-side gearing. However, the geared domestic dehumidifier has not previously been investigated experimentally for a wide range of airflow settings typical of domestic dehumidifier operation, or with different throttling schemes, and the efficiency of these systems is not well understood under household conditions.In this work, we measure the performance of a commercial domestic dehumidifier, adapted for laboratory testing, in ungeared and geared modes at a wide range of airflows and with both capillary and thermostatic expansion valve throttling to understand how the system performance is effected, for air volume flow rates of 29 L/s - 48 L/s. The measurements show that both capillary and thermostatic expansion valve equipped domestic dehumidifiers can improve energy efficiency in the geared operation mode, but the capillary equipped system is more prone to frosting and wet compression, degrading performance.