Victorum Exhaust Air Heat Pump Installation Guide
25
Victorum EAHP Unit
Piping
Sizing, positioning and pre-charge pressure of the heating system
expansion vessel
The Exhaust Air Heat Pump does not have an expansion vessel incorporated. The installer must
ensure the system is protected from the effects of expansion by installing a suitably sized expansion
vessel.
The vessel prevents water pressure spikes in the system by absorbing the increased pressure as
the temperature increases.
•
Only use dry nitrogen or air to set the expansion vessel pressure.
•
Inappropriate setting of the expansion vessel pre-charge pressure will lead to malfunction of
the system.
•
The pressure should only be set and/or adjusted by a competent installer.
•
The adjusting of the presure should be done before the expansion vessel is installed - i.e the pipe
connection must be open to atmosphere.
The vessel must be sized in accordance with EN 12828. The following system data will assist in
sizing a vessel:
1
Vessel pre-charge pressure
*0.5 bar, recommended
2
Safety valve set pressure
3 bar, industry standard
3
**The difference in height (H)
0 m, typical install setup
4
Total system volume, in litres
Calculated by the installer
5
System maximum temperature
65°C
6
% Antifreeze glycol in the system
Zero, as its an indoor installation
*A pre-charge pressure of 0.5 bar equates to a static head of 5 metres.
**The difference in height (m) is the difference between the position in which the safety valve is
installed and the position of the vessel.
Pre-Charge Pressure 0.5 bar
Pre-Charge Pressure 1.0 bar
