Dedicated Outdoor Air Systems. Recommended Options for Various Climatic Conditions of India.

Dedicated Outdoor Air Systems, DOAS, are increasingly being considered in air-conditioning for providing better Indoor Air Quality, IAQ, and reducing energy consumption. DOAS can be designed to handle all or part of the space latent loads along with some part of sensible load. DOAS usually operate along with some other sensible cooling equipment, mainly Variable Refrigerant Flow, VRF system, Radiant Panels, RP, Chilled Beams, CB, or conventional Fan Coil Units, FCU. Non-compressor based DOAS options are investigated to optimally integrate them with various existing conventional air-conditioning systems. VRF systems have emerged as one of the energy efficient HVAC options in recent years, therefore judiciously combining DOAS with VRF system is investigated. The paper lists various configurations of DOAS and recommends best option for energy efficient and cost effective integration with balance air conditioning system. A novel versatile DOAS hardware configuration, with fewer components is introduced and investigated for suitability for various Indian climatic conditions. Best configurations for year round operation in different climatic conditions of India are suggested. Energy savings offered by the new patented DOAS configuration is 20 to 30% higher than conventional cross-flow based DOAS.