Air-to-water Heat Pump
29
13.3 Safety consideration
Checking for presence of refrigerant
The area shall be checked with an appropriate refrigerant detector prior to and during work, to
ensure the technician is aware of potentially toxic or flammable atmospheres. Ensure that the leak
detection equipment being used is suitable for use with all applicable refrigerants, i.e. non-sparking,
adequately sealed or intrinsically safe.
Ventilated area
Ensure that the area is in the open or that it is adequately ventilated before breaking into the system
or conducting any hot work. A degree of ventilation shall continue during the period that the work is
carried out. The ventilation should safely disperse any released refrigerant and preferably expel it
externally into the atmosphere.
13.4 Notice before Seasonal Use
(1) Check whether air inlets and air outlets of units is blocked
(2) Check whether ground connection is reliable or not
(3) If unit starts up after not operating for a long time, it should be power on 8 hours before
operation starts so as to preheat the outdoor compressor
(4) Precautions for Freeze Protection in Winter
Under subzero climatic conditions in winter, anti-freeze fluid must be added into the water cycle and
external water pipes should be properly insulated. Glycol solution is recommended as the anti-freeze
fluid.
Concentration
%
Freezing Temp
°C
Concentration
%
Freezing Temp
°C
Concentration
%
Freezing Temp
°C
4.6
-2
19.8
-10
35
-21
8.4
-4
23.6
-13
38.8
-26
12.2
-5
27.4
-15
42.6
-29
16
-7
31.2
-17
46.4
-33
NOTE:
“Concentration” listed in the table above indicates the mass concentration.
