Review article

The article discusses the results of simulation modelingof a heat recovery system based on an air-to-air heat pump (AHP) integrated into an air handling unit (AHU) ventilation system. The dependences of the operation of the built-in AHP in the AHU with their various layouts are obtained. A decrease in outdoor air temperature has a significant effect on the coefficient of performance (COP) of AHP. In an AHU with an air-to-air utilizer, when installing the AHP condenser in the supply air duct after the utilizer, and the evaporator in the exhaust air duct before it, the COP increases with a decrease in outdoor air temperature, but when the evaporator is transferred behind the air-to-air utilizer, the COP decreases. The introduction of AHP into the AHU is accompanied by increased aerodynamic drag, which requires additional electrical power supplied to the fans, which reduces the efficiency of the refrigerating machine. The use of AHP as part of the AHU increases the temperature efficiency of the ventilation unit by 15-30 %, and the combined AHP with the air-to-air utilizer reduces energy consumption by25-60 %.