Daikin Altherma 3 M - Formula to Calculate the Expansion Vessel Pre-Pressure; To Check the Water Volume and Flow Rate

8 | Piping installation
Installer reference guide
76
EBLA09~16DA + EDLA09~16DA
Daikin Altherma 3 M
4P620241-1 – 2020.06
c
d
a b
a Recirculation connection
b Hot water connection
c Shower
d Recirculation pump
8.1.2 Formula to calculate the expansion vessel pre-pressure
The pre-pressure (Pg) of the vessel depends on the installation height difference
(H):
Pg=0.3+(H/10) (bar)
8.1.3 To check the water volume and flow rate
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… Then the minimum water volume
is…
Cooling operation 20l
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
0l
Preheating on the tank is not possible, but
a backup heater (internal or external) is
present.
20l
Preheating on the tank is not possible, and
there is no backup heater.
50l
INFORMATION
In critical processes, or in rooms with a high heat load, extra water might be
required.