The macro "ERC_Glycol" provides modulating control of energy recovery equipment of an air handling unit and operates in sequence with other output modules or as standalone module. The module has integrated features for plant mode overrides.

The air-liquid-air system with glycol as liquid medium has a pump in the return pipe of the exhaust air coil. The energy recovery systems are equipped with temperature sensors which are connected to macro inputs and are respectively:
- Inlet air temperature sensor (IAT). This sensor is mounted in the outside air duct. In the event that this sensor is not fitted, the macro input “FilteredOATemp” from macro "Filtered Temperature" will be used as inlet air temperature.
- Return air temperature sensor (RAT). This sensor is mounted in the return or exhaust air duct at the inlet side of the energy recovery air coil.
- Energy recovery temperature sensor (ERT). This sensor is mounted in the liquid part of the air-liquid-air energy recovery system. It is mounted into the return pipe of the exhaust air coil for a glycol system or into the return pipe of the outside air coil for a water system. If this sensor is not available, freeze protection is not possible.