Presents an analytical procedure for evaluating the air change rate in a room due to the temperature difference between the interior and exterior, which occurs when a door or window is opened.
Describes a method, derived from bibliographical research, for air infiltration calculation in a multistorey building. The method may be used both for computer calculations, in order to determine the building thermal balance hour by hour, and for steady state hand calculations. Analytical and experimental relations have been examined for the determination of the air flow rate due to wind and stack effect.
After a general preliminary discussion of the meaning of "heat recovery" and possible systems for carrying it out, the author examines the possible different ways of transferring thermal energy from one fluid to another by means of an indirect heat exchanger. Air-to-air systems are in particular analyzed, examining the operating features of the various exchange types(rotating, fixed plate, multiple tower and finned tube exchangers). The paper concludes with a series of considerations on both energetic and economic aspects of thermal energy recovery.