HRX-OM-M090 
Chapter 7   Control, Inspection and Cleaning 
 
 
HRS Series  7.1 Control of Circulating Fluid Quality 
 
 
7-1
Chapter 7  Control, Inspection and 
Cleaning 
7.1  Control of Circulating Fluid Quality 
 
 
 
 
 
 
 
 
Table 7-1 Quality standard for fresh water (tap water) 
Standard value 
  Item  Product 
For circulating fluid  For facility water 
pH (at 25
o
C) 
- 
6.0 to 8.0  6.5 to 8.2 
Electric conductance   
(at 25
o
C) 
[μS/cm] 
100 to 300  100 to 800 
Chloride ion  [mg/L] 
50 or less  200 or less 
Sulfuric acid ion  [mg/L] 
50 or less  200 or less 
Acid consumption   
(at pH 4.8) 
[mg/L] 
50 or less  100 or less 
Total hardness  [mg/L] 
70 or less  200 or less 
Calcium hardness  [mg/L] 
50 or less  150 or less 
Standard 
item 
Ion silica  [mg/L] 
30 or less  50 or less 
Iron [mg/L] 
0.3 or less  1.0 or less 
Copper [mg/L] 
0.1 or less  0.3 or less 
Sulfide ion  [mg/L] 
Not detected  Not detected 
Ammonium ion  [mg/L] 
0.1 or less  1.0 or less 
Residual chlorine  [mg/L] 
0.3 or less  0.3 or less 
Referential 
item 
Separation carbonic 
acid 
[mg/L] 
4.0 or less  4.0 or less 
∗ Quoted from JRA-GL-02-1994, The Japan Refrigeration and Air Conditioning Industry Association. 
 
 
Use specified circulating fluids only. If other fluids are used, they may 
damage the product or result in dangerous hazards. 
When using fresh water (tap water) ensure that it satisfies the water 
standard shown in the table below. 
Clean the tank, circulating fluid circuit, and change the circulating fluid
in the tank if any problems are found during the regular check. 
Additionally, even if no problems are found, it is necessary to change 
the fluid once every 3 months in case evaporation of the fluid causes 
concentration of impurities. Refer to the page containing "7.2 
Inspection and Cleaning" for the regular check.