R32
Split Type - Air Source Heat Pump 20220105
65
Propylene Glycol
Concentration
of
propylene
glycol(%)
Modification coefficient
Freezing point
(C)
Cooling capacity
Power input
Water resistance
Water flow
0 1.000
1.000
1.000
1.000
0
10 0.976
0.966
1.071
1.000
-3
20 0.961
0.992
1.189
1.016
-7
30 0.948
0.988
1.380
1.034
-13
40 0.938
0.984
1.728
1.078
-22
50 0.925
0.975
2.150
1.125
-35
Uninhibited glycol will turn acidic under the influence of oxygen. This process is accelerated by
presence of copper and at higher temperatures. The acidic uninhibited glycol attacks metal surfaces and
forms galvanic corrosion cells that cause severe damage to the system. It is of extreme importance:
That the water treatment is correctly executed by a qualified water specialist.
That a glycol with corrosion inhibitors is selected to counteract acids formed by the oxidation of glycols.
That in case of an installation with a domestic hot water tank, only the use of propylene glycol is
allowed. In other installations the use of ethylene glycol is fine.
That no automotive glycol is used because their corrosion inhibitors have a limited lifetime and contain
silicates that can foul or plug the system;
That galvanized piping is not used in glycol systems since it may lead to the precipitation of certain
elements in the glycols corrosion inhibitor;
To ensure that the glycol is compatible with the materials used in the system
3.5 Water Flow Switch
Water may enter into the flow switch and cannot be drained out and may freeze when the temperature is
low enough. The flow switch should be removed and dried, then can be reinstalled in the unit.
CounterclockWise rotation, remove the water flow switch.
Drying the water flow switch completely.
3.6 Adding Water
Connect the water supply to the fill valve and open the valve.
Make sure the automatic air purge valve is open (at least 2 turns).
Fill with water until the manometer indicates a pressure of approximately 2.0 bars. Remove air in the circuit
as much as possible using the air purge valve. Air in the water circuit could lead to malfunction of the backup
electric heater.
3.7 Water Piping Insulation
The complete water circuit including all piping, water piping must be insulated to prevent condensation
during cooling operation and reduction of the heating and cooling capacity as well as prevention of freezing of
the outside water piping during winter. The insulation material should at least of B1 fire resistance rating and
complies with all applicable legislation
The thickness of the sealing materials must be at least 13mm with thermal conductivity 0.039W/mK in order
to prevent freezing on the outside water piping. If the outdoor ambient temperature is higher than 30C and the
