AirWatt - Installation and operating manual
Field of use
External heat recovery unit AirWatt is intended for recapturing waste heat, which is
generated at air compression. Up to 70% of energy, consumed by compressor may be in
form of heat. Recovered heat may be used for heating domestic hot water or for central
heating. Recovered heat may represents significant savings and reduced load on
environment.
Principle of operation
AirWatt has two separate piping systems, through which flows water or oil. Device is
connected to oil circuit in compressor. Inside built in plate heat exchanger oil cools and
water gains heat.
Unit is regulated and protected with thermostatic valve, which maintains oil temperature
above set value. Correct oil temperature is crucial for safe and long operation of screw
compressor. Water does not start to flow, until oil temperature reaches set value. Switch on
temperature of thermostatic valve can be set between 60°C and 90°C. Device also has two
thermometers installed on housing to monitor inlet and outlet water temperature.
Heat recovery
There are four connections on the back side of device. Two are connected to compressor oil
circuit, the other two are for water circuit. When compressor is in operation, compressor oil
constantly flows through AirWatt heat exchanger oil piping and plate heat exchanger. Water
does not start to flow through thermostatic valve, until oil temperature reaches the set
value on the valve. When oil temperature reaches desired value, thermostatic valve opens
water flow through plate heat exchanger. Heat is extracted fr
om oil and it’s temperature
drops. Water gains heat. The lower the water flow, the higher it’s temperature at outlet
gets.