Formula To Calculate The Expansion Vessel Pre-Pressure; To Check The Water Volume And Flow Rate - Daikin ERLA-DV17 Installer's Reference Manual

8 | Piping installation

8.5.2 Formula to calculate the expansion vessel pre-pressure

8.5.3 To check the water volume and flow rate

Installer reference guide
108
▪ 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.
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 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
Check that the total water volume in the installation is higher than the minimum
water volume, the internal water volume of the indoor unit NOT included:
If...
Heating operation
INFORMATION
In critical processes, or in rooms with a high heat load, extra water might be
required.
NOTICE
When circulation in each space heating/cooling loop is controlled by remotely
controlled valves, it is important that the minimum water volume is guaranteed,
even if all of the valves are closed.
c
d
Then the minimum water volume
is...
20 l
ERLA11~16D + EBVH16SU23D
Daikin Altherma 3 R F
4P655196-1A – 2022.05