Dynamic Simulation of Solar-Powered Heating and Cooling System for an Office Building Using TRNSYS: A Case Study in Kerman

Recently, novel techniques have been developed in building industries to use solar heating and cooling systems. The current study develops a Solar-powered Heating and Cooling (SHC) system for an office building in Kerman and assesses the transient dynamics of this system and office indoor temperature. To this end, TRNSYS simulation software is utilized to simulate system dynamics. The developed system comprises Evacuated-Tube solar Collectors (ETCs), heat storage tank, heat exchanger, circulating pumps, axillary furnace, cooling tower, single-effect absorption chiller, and air handling unit. The office indoor temperature is assessed in two scenarios, including commonly-insulated and well-insulated envelopes, while window awnings are used to prevent the sun from shining directly through the windows. The results illustrate that the SHC system can meet the thermal loads and provide thermal comfort in line with ASHRAE standards. The indoor temperature reaches 21 °C and 24 °C on cold winter and hot summer days by using the SHC system; however, without the SHC system, the indoor temperature experiences 15 °C and 34 °C on cold and hot days, respectively. The SHC system provides 45 °C and 15 °C supply air on cold and hot days to keep the indoor temperature in the desired range. A thermostat monitors the indoor temperature and saves energy by turning off the system when no heating or cooling is required. Furthermore, the ETCs can run the SHC system for a long time during daytime hours, but the axillary heater is still essential to work at the beginning of the morning.