Energy recovery in ventilation systems: a worldwide energy saving and environmental protection technology.

For more than 20 years, energy recovery systems have been operated successfully in European countries in comfort and industrial ventilation systems in order to reduce the heating and cooling capacity as well as to reduce the annual energy consumption for the treatment of supply air. By 1991 the total heating capacity of all installed energy recovery systems in Europe was about 60.000 MW and the equivalent of the annual energy savings was about 10 million tons of oil. This very impressive result of an energy saving technology also includes the annual reduction of emissions of all environmental polluting products: 10 million tons of annual oil savings are corresponding with the reduction of about 50.000 tons of SO2 and 40 million tons of C02 Apart from being an important economic factor both at the private and the national level, energy recovery systems thus also make an important contribution to energy conservation and environmental protection [1].