Daikin Altherma ERGA04E V3 Series - Formula to Calculate the Expansion Vessel Pre-Pressure; To Check the Water Volume and Flow Rate

8 | Piping installation
Installer reference guide
100
ERGA04~08E + EHVH04+08SU18+23E
Daikin Altherma 3 R F
4P629090-1C – 2022.08
c Pressure reducing valve (set to 3.5bar) (part of the domestic hot water tank kit)
d Indoor unit
e Dedicated 3.5bar feed – to/from DHW tank
f Dedicated 3.5bar feed – cold water
g Cold water taps
h Hot water taps
i Shower
▪ Domestic hot water tank – Pressure relief valve. A pressure relief valve (part of
the inlet control group) with an opening pressure of 8 bar prevents excessive
water pressure in the water circuit.
▪ Domestic hot water tank – Pressure and temperature relief valve. The pressure
and temperature relief valve prevents excessive water pressure (≥10 bar) and
excessive water temperature (>95°C) in the domestic hot water tank.
▪ Thermostatic mixing valves. In accordance with the applicable legislation, it may
be necessary to install thermostatic mixing valves.
▪ Hygienic measures. The installation must be in compliance with the applicable
legislation and may require additional hygienic installation measures.
▪ Recirculation pump. In accordance with the applicable legislation, it may be
required to connect a recirculation pump in between the hot water end point
and the recirculation connection of the domestic hot water tank.
c
d
a b
a Recirculation connection
b Hot water connection
c Shower
d Recirculation pump
▪ Valve towards expansion vessel. The valve towards the expansion vessel (if
equipped) MUST be open.
8.5.2 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)
8.5.3 To check the water volume and flow rate
The indoor unit has an expansion vessel of 10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
There are no requirements for the minimum water volume.
INFORMATION
In critical processes, or in rooms with a high heat load, extra water might be
required.