Formula To Calculate The Expansion Vessel Pre-Pressure; To Check The Water Volume And Flow Rate - Daikin Altherma 3 M Installer's Reference Manual

8 | Piping installation

8.1.2 Formula to calculate the expansion vessel pre-pressure

8.1.3 To check the water volume and flow rate

Installer reference guide
76
a b
a Recirculation connection
b Hot water connection
c Shower
d Recirculation pump
The pre-pressure (Pg) of the vessel depends on the installation height difference
(H):
Pg=0.3+(H/10) (bar)
The outdoor unit has an expansion vessel of 8 litre with a factory-set pre-pressure
of 1 bar.
To make sure that the unit operates properly:
▪ You must check the minimum and maximum water volume.
▪ You might need to adjust the pre-pressure of the expansion vessel.
Minimum water volume
Check that the total water volume in the installation is higher than the minimum
water volume, the internal water volume of the outdoor unit NOT included:
If...
Cooling operation
Heating/defrost operation and...
Preheating on the tank is possible.
This is possible in the following cases:
▪ EKHWP* tank + booster heater
▪ EKHWS*D* tank + booster heater + DHW
pump
Preheating on the tank is not possible, but
a backup heater (internal or external) is
present.
Preheating on the tank is not possible, and
there is no backup heater.
INFORMATION
In critical processes, or in rooms with a high heat load, extra water might be
required.
c
d
Then the minimum water volume
is...
20 l
0 l
20 l
50 l
EBLA09~16DA + EDLA09~16DA
Daikin Altherma 3 M
4P620241-1 – 2020.06