Development and Validation of a Water-to-Air Heat Pump Model using Modelica

Water-to-air heat pumps are widely used Heating, Ventilation, and Air Conditioning (HVAC) devices due to their versatility and energy efficiency. However, there is a scarcity of readily available Modelica models that support reversible operation (heating and cooling modes), use compressor speed as the control signal, and accurately predict the system performance. To address this gap, this paper presents a speed-input water-to-air heat pump model developed using Modelica. Performance curves are employed to represent the functionality and predict the system’s capacity and power usage. To validate the proposed model’s effectiveness, manufacturer-provided data are used to generate the performance curves. The model, based on these curves, is then used to simulate testing conditions, which are implemented in a real heat pump testbed. The comparison between simulated and measured values shows that the errors during normal operation stages are within an acceptable range, demonstrating the effectiveness of the developed water-to-air heat pump model.