Performance evaluation of two cross type indirect evaporative air coolers

Abstract

The main purpose of this paper is to conduct comparative analysis of the two types of indirect evaporative coolers (IEC): a typical IEC and a regenerative IEC. The performance of two indirect evaporative coolers were investigated through experimentation under the constant inlet air condition with variable air flow rates. The hot and dry outdoor air condition is selected as an inlet primary air condition which represents the dehumidified air passed through liquid desiccant unit in summer. To compare the cooling capacity of typical IEC and regenerative IEC, the supply air flow rate of regenerative IEC is adjusted in two modes: 1) equal supply air flow rate with typical IEC, 2) 30% less than the supply air flow rate of typical IEC. The performances of two types of IEC are evaluated through experiments in environmental chambers and then validated with numerical models. As a result, the typical IEC showed highest wet-bulb efficiency of 52% while that of regenerative IEC was 36% when supplied with more primary air flow due to extracted secondary air.