A novel method to determine air leakage in heat pump clothes dryers

Although heat pump clothes dryers offer the potential to save a significant amount of energy as compared to conventional vented electric dryers; they are prone to air leakage that can limit their efficiency gain. This study serves to develop a novel method of quantifying leakage, and to determine specific leakage locations in the dryer drum and air circulation system. The method follows an ASTM (American Society of Testing and Materials) standard, which is used to determine air leakage area in a household ventilation system through fan pressurization. This ASTM method is adapted to the dryer system, and the leakage area is determined by an analysis of the leakage volumetric flow - pressure relationship. The procedure presents a framework that determines and quantifies major components contributing to leakage in HPCDs. The novel method can improve component design features, resulting in more efficient HPCD systems. •Leakage area calculated from combining the ASTM standard with Bernoulli's equation.•Leakage area is determined by the leakage volumetric flow rate and pressure relationship.•Leakage points are small in area and can be approximated as orifices.•The method offers potential for further improvement of HPCD efficiency.