Techno-Economic Assessment of Heat Recovery in Series Condensers Arrangement: Hot and Humid Regions

Abstract

A direct expansion (DX) HVAC system is an efficient way to supply fresh and dehumidified air to a built environment. To improve the efficiency of a conventional DX system in hot and humid regions, fresh air dehumidification and conditioning systems with energy recovery measures are the key equipment to reach such a goal. To achieve this goal an integrated system is proposed. The integrated system substitutes the reheat coil with an extra condenser in series arrangement with the main condenser to reheat the supply air while mixing the ventilated air with condenser cooling air. Modeling has broken down into two parts. Psychometric part which has been modeled using EnergyPlus and EES software, and DX system in which data is received via psychometric part, and has been modeled and evaluated by EES software. The case study is located in Bandar-e-Abbas city, quasi-dynamic modeling is to be conducted and results will be analyzed correspondingly. The integrated system's energy saving is 32-48%. Also, system's COP has increased from 1.55 to 3.46 for outside air fraction (ventilation rate) of 0%, and from 2.37 to 3.47 for outside air fraction of 100%. Finally the payback period is roughly less than 4 years.