Daikin ERLA03DAV3 - Formula to Calculate the Expansion Vessel Pre-Pressure; To Check the Water Volume and Flow Rate

8 | Piping installation
Installer reference guide
78
ERLA03DAV3 + EHFZ03S18DJ3V
Daikin Altherma 3 R F
4P596821-1B – 2021.10
▪ Domestic hot water tank – Standstills. In cases where during longer periods of
time there is no consumption of hot water, the equipment MUST be flushed with
fresh water before usage.
▪ Domestic hot water tank – Disinfection. For the disinfection function of the
domestic hot water tank, see "10.4.2 Domestic hot water control:
advanced"[4139].
▪ 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
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.