28
Air-to-Water Heat Pump
Installation of Indoor Unit
Setting the pressure for the expansion vessel
P
0
• Before filling the system with water, check and set the pressure
P
0
. The expansion vessel is factory
set to the pressure specified on its data label. For correct operation of the system, set the pressure
P
0
according to the equation below. The filling must not exceed the maximum operational pressure
specified on the data label of the expansion vessel.
• Calculate the
P
0
pressure value with the help of the equation:
If the calculation shows a pressure lower than 1 bar, set the pressure of the expansion vessel to 1 bar.
P
0
[bar] – pressure in the expansion vessel,
P
0
min [bar] – minimum allowed pressure of the heating system,
P
0
max [bar] – maximum allowed pressure of the heating system,
H
[m] – Height of the heating system.
• Set the amount of pressure in the expansion vessel by releasing or adding dry nitrogen.
• Record the new value of the pressure
P
0
on the data label.
• Open the closing valve of the expansion vessel carefully, open the vents and close the drain.
Filling the heating system
• Use the filling valve to fill the system with water of suitable quality (with anti-corrosion additives,
etc.) to the pressure
P
F
.
P
F
[bar] =
P
0
[bar] + 0,3 [bar]
Filling the system to the final pressure
• The final pressure of the system is determined by heating the system to the maximum heating tem-
perature (thermal degassing).
• Turn off the circulation pumps, open the vents and vent the system.
• Fill the system up to the final pressure which is 0.5 bar lower than the venting pressure of the safety
valve.
P
E
[bar] ≤
P
sv
[bar] - 0,5 [bar]
P
E
– the final pressure of the system,
P
SV
– the pressure of the safety valve.
P
0
[bar] =
+ 0,2 [bar]
1)
H
[m]
10
1,MFL69676201,영영 2017. 3. 8. 영영 3:07 Page 28
