Applicability of thermoelectric heat pump in a dedicated outdoor air system

Abstract

The main objective of this research is to propose a dedicated outdoor air system assisted by a thermoelectric heat pump, and to evaluate the operating energy performance of the proposed system compared with a reference system. The proposed dedicated outdoor air system consists of an enthalpy wheel, a desiccant wheel, and the thermoelectric heat pump to condition the introduced outdoor air to provide required ventilation air to the conditioned zone at neutral temperature, while the reference system consists of a desiccant wheel, a sensible heat exchanger, a cooling coil, and a regeneration air heater. To develop an empirical model for the thermoelectric heat pump applicable to the energy simulation of the proposed system, a thermoelectric heat pump prototype was built, and its operating data were collected in a fully controlled laboratory environment. By integrating the existing models of each system component used in both dedicated outdoor air systems, detailed energy simulations were performed to compare the energy performance of the proposed dedicated outdoor air system with the reference system. The results showed that the proposed system assisted by the thermoelectric heat pump consumed 23% more operating energy than the reference system because of the lower coefficient of performance of the thermoelectric heat pump compared with the conventional vapor compression system. For comparable energy performance, the proposed dedicated outdoor air system should have heat exchange effectiveness values greater than 49% at least at both the process and secondary air channels of the thermoelectric heat pump, and the figure of merit of the thermoelectric modules used in the thermoelectric heat pump should be over 1.35.