Energy saving potential of thermoelectric radiant cooling panels with a dedicated outdoor air system

Abstract

The objective of this study is to investigate the energy saving potential of a dedicated outdoor air system (DOAS) with a thermoelectric module radiant cooling panel (TEM-RCP) by comparing it with those of both a conventional variable air volume (VAV) system and a DOAS with hydraulic ceiling radiant cooling panels (CRCP) via a detailed energy simulation. The theoretical and empirical models for each component were used to estimate the energy performance of a VAV system and a DOAS with CRCP. Additionally, the TEM-RCP was analyzed by using the developed simulation models based on the semi-black box model. Hourly simulations were conducted to measure the annual energy performance. The results indicated that the DOAS with a TEM-RCP consumed 40.7% less operating energy annually when compared with that of the conventional VAV system while the proposed system exhibited only 1.0% more annual energy consumption when compared with the DOAS with hydraulic CRCP given the relatively low dimensionless figure of merit (ZT) of the TEMs (i.e., 0.73) that is used in the TEM-RCP. However, the average coefficient of performance (COP) of the TEM-RCP for cooling was 8.3, which is significantly higher than that of the conventional CRCP (4.6) during the operation period. This is because the TEM-RCP uses a cooling tower for heat removal, and its cooling water temperature is sufficiently low without requiring additional cooling of the TEM except during summer. Therefore, TEM maintains radiant panel temperature with low electric energy consumption. The study also indicated that if the ZT value of TEMs exceeded 0.75, then the proposed system exhibited lower annual energy consumption when compared to that of the DOAS with CRCP.