Water Volume And Expansion Vessel Pressure; Selection Of Expansion Vessel - Gree Versati III GRS-CQ4.0Pd/NhH2-E Owner's Manual

Air-to-water Heat Pump Split Versati

7.7 Water volume and expansion vessel pressure

Notes
(a) The expansion vessel is 10 liters and 1bar pre-pressurized;
(b) Total water volume of 280 liters is default; if total water is changed because of installation condition, the
pre-pressure should be adjusted to secure proper operation. If the indoor unit is located at the highest position,
adjustment is not required;
(c) Minimum total water volume is 20 liters;
(d) To adjust pre-pressure, use nitrogen gas by certificated installer.

7.8 Selection of expansion vessel

Formula:
V--- Volume of expansion vessel
C--- Total water volume
P --- Pre-set pressure of expansion vessel
1
P -- The highest pressure during running of the system (that is the action pressure of safety valve.)
2
e---The expansion factor of water (the difference between the expansion factor of the original water temperature
and that of highest water temperature.)
Temperature(°C)
2.5
2.0
1.5
1.0
0.5
0.0
0 50 100 150
Maximum total water volume(liter)
Water expansion factor in different temperature
0
4
10
20
30
40
45
50
55
60
65
200 250 300 350
Expansion factor (e)
24
SPLIT TYPE
400
0.00013
0
0.00027
0.00177
0.00435
0.00782
0.0099
0.0121
0.0145
0.0171
0.0198