Gree GRS-CQ10Pd/NhG-M - Page 95

Installation
Example 2:
The unit is installed on the highest spot of the water system and the total water volume is
100L.
As the volume of water system is higher than 75L, it is necessary to adjust the pressure of the
expansion vessel be lower.
The formula of calculating pressure
Pg=(H/10+0.3)=(0/10+0.3)=0.3 Bar
The maximum volume of the water system is about 410L. As the actual volume of the water system is
118L, the expansion vessel meets the installing requirement.
Adjust the pre-set pressure of the expansion vessel from 1.5Bar to 0.3Bar.
4.6.4 Selection of expansion vessel
Formula:
V--- Volume of expansion vessel
C--- Total water volume
P1--- Pre-set pressure of expansion vessel
P2-- The highest pressure during running of the system (that is the action pressure of safety valve.)
e---The expansion factor of water (the difference between the expansion factor of the original water
temperature and that of highest water temperature.)
Water expansion factor in different temperature
Temperature
Expansion factor e
0
0.00013
4
0
10
0.00027
20
0.00177
30
0.00435
40
0.00782
45
0.0099
50
0.0121
55
0.0145
60
0.0171
65
0.0198
70
0.0227
75
0.0258
80
0.029
85
0.0324
90
0.0359
95
0.0396
100
0.0434