Comparative assessment of different air‐conditioning systems for nearly/net zero‐energy buildings
Gaurav Singh, Ranjan Das
Abstract
This study deals with the performance of different air-conditioning strategies for achieving the target of nearly/net zero energy in a medium-scale building under various environmental conditions. In particular, vapour compression (VC), vapour absorption (VA), and integration of radiant cooling technology are analysed using renewable energy resources and solar photovoltaic (PV)-based electricity. Four different kinds of air-conditioning configurations are considered: VC-based, VA-based, VC-radiant air-conditioning technology with VC dedicated outdoor air system (DOAS) and VA radiant air-conditioning technology with VC-DOAS. Numerical model validations with the benchmark standards are done for VC- and VA-based systems. In particular, annual electric consumption, electricity generation, thermal load generation among all configurations, emissions and solar fractions are studied. The present study shows that target of nearly/net zero-energy building can be achieved in an efficient manner through radiant VC-based system with VC-DOAS for hot-dry and composite (ie, hot-dry with higher humidity) environment conditions. However, for warm-humid environment, complete net zero is not possible, but up to 74% of net zero target can be assured with VC-based radiant and DOAS. With respect to the conventional VC-based system, the payback period assessment for the most suitable nearly/net zero building cooling system varies in the range of 5-9 years, depending on the environmental conditions.