The International Institute of Refrigeration (IIR) has published two new Informatory Notes on energy recovery, Energy Recovery in Mechanical Ventilation Systems and Air-to-Air Energy Recovery Equipment.
The thermal loads of buildings, apart from internal gains, can be classified into two main categories: losses or gains through the envelope and ventilation loads. Ventilation loads are becoming more important as air purity standards and thus fresh air supply rates are increasing.
Heat recovery from the exhaust air can strongly reduce these loads by pre-heating or pre-cooling the fresh inlet air. Heat recovery in a ventilation system allows significant energy savings, particularly when outdoor conditions differ greatly from the indoor ones. Moreover, when a recovery system is provided, the installed capacity for heating and cooling can be strongly reduced.
Energy Recovery in Mechanical Ventilation Systems analyses the possible energy, environmental and economic benefits of this technology according the climate in which the building is located. It concludes that heat recovery in mechanical ventilation systems may reduce the usage of fossil fuel with payback periods of one or two years.
Air-to-Air Energy Recovery Equipment describes the performance, characteristics and operating modes of the great variety of appliances available for use in building ventilation heat recovery or in process-to-process industrial heat recovery. The energy benefits of heat recovery can allow energy cost reductions that can easily exceed 70%.