A theoretical study of the effects of different heating loads on the exergy performance of water-based and air-based space heating systems in buildings

The present study investigated theoretically the exergy performance of floor heating, radiators, and air heating under three different space loads 10, 30 50 W/m2. effects supply return water temperatures were studied for system. All systems assumed to be connected a boiler. system was further analyzed assuming an air-to-water heat pump, ground-source pump. Floor optimal due its low demand. separation thermal environmental conditioning ventilation efficient solution. results prove thermodynamically that renewables (i.e., ground source in study) temperature are resource- exergy-efficient combination proven by their efficiencies up 10.5%. critical COP concept validated (2.57 this study). power use auxiliary components might seem negligible terms energy; however, it is as affects drastically. relative importance becomes more at loads.