Application of The Exergy Concept to Ventilation Using Heat Recovery from Exhaust Air

This paper describes steady-state energy and exergy analyses on an instantaneous and on adaily basis for dwelling ventilation systems and domestic hot water DHW production systems. The ventilation uses mechanical exhaust with environmental air supply without heat recovery or balanced ventilation with heat recovery. The exhaust ventilation air is used to preheat DHW, using a heat exchanger or a heat pump. Energy and exergy demands in winter days for De bilt, the Netherlands, are presented at the component level, in terms of heat and electricity, for the systems. The results indicates that for these winter days the total energy demands, but not the total exergy demands, of balanced ventilation and DHW production with preheat by the exhaust ventilation air using a heat pump are lowest. The total exergy demands are dominated by exergy of electricity input to heat recovery unit and the heat pump.