Application of the exergy concept to design efficient mechanical exhaust ventilation systems

This work presents energy and exergy comparison of several design options for combination between dwelling ventilation and domestic hot water production. The dwelling ventilation uses mechanical exhaust with natural air supply (without heat recovery) or balanced ventilation with heat recovery. The outlet ventilation air is used as a heat source for domestic hot water, by using a heat exchanger or a heat pump.


This paper first introduces the concept of “exergy”, which quantifies what is consumed by any working systems from man-made systems such as heat engines to biological systems including human body. “Exergy” balance equation for a system can be derived by c

Increased Energy Efficiency and Improved Comfort

This paper summarises the work of the LowEx co-operation /1/. The aim was to promote rational use ofenergy by encouraging the use of low temperature heating systems and high temperature cooling systems ofbuildings. These systems can use a variety of fuels and renewable energy sources. Energy is used efficientlywhile providing a comfortable indoor climate. Exergy defines the quality of energy and is a concept fordesigning and assessing different heating and cooling systems. Application of exergy analysis into buildingshas not been common before.

Comfortable High-Performance and Low-Exergy Built Environment

This paper outlines the applicability of the “exergy” concept to describe the built environment for a better futuristic view of heating and cooling systems to be developed. We briefly review the fundamental laws of thermodynamics aiming at the derivation

Exergy Analysis as an Assessment Tool of Heat Recovery of Dwelling Ventilation Systems

In cold and moderate climates, improvements in building shell insulation and air-tightness imply a shiftin heating loads from transmission and infiltration towards ventilation. Heat recovery from the ventilation airflow plays an increasingly important role in minimising energy needs. Such heat recovery systems rely on the input of electric power (to drive fans, heat pumps, etc.) in order to recover thermal energy. Since electricity input is relatively small compared to the amounts of thermal energy recovered, such systems are efficient from an energy viewpoint.