In air-conditioning (A/C) systems with air-cooled condensers, the condensing unit has to be kept in the open for easy access to outdoor air in order to efficiently dissipate heat. During daytime, the solar radiation falling on the surfaces of the condenser and the high ambient temperatures can be detrimental for the energy performance. The effectiveness of shading the condensing unit to mitigate this adverse impact is investigated in this paper. A limiting analysis compares the performance of several A/C systems with ideal shade to those with ideal solar heat gain. The comparison is based on a theoretical model and data from equipment catalogs. The theoretical increase in the coefficient of performance (COP) due to shading is found to be within 2.5%. Furthermore, this small improvement in ideal efficiency decreases at higher ambient temperatures, when enhancements to efficiency are more needed. The actual efficiency improvement due to shading is not expected to exceed 1%, and the daily energy savings will be lower.
展开▼
