Daikin Altherma 3 R W, Installer'S Reference Manual

Page: 103 / 296

8 | Piping installation
Installer reference guide
103
ERGA04~08EA + EHBH/X04+08EF
Daikin Altherma 3 R W
4P629085-1B – 2021.11
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
Check that the total water volume in the installation is minimum 10 litres, the
internal water volume of the indoor unit NOT included.
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.
FHL1
FHL2
FHL3
M1
T1
M2
T2
M3
T3
f d c b a
f
g h
e
a Outdoor unit
b Indoor unit
c Heat exchanger
d Backup heater
e Pump
f Shut-off valve
g Collector (field supply)
h Overpressure bypass valve (delivered as accessory)
FHL1...3 Floor heating loop (field supply)
T1...3 Individual room thermostat (optional)
M1...3 Individual motorised valve to control loop FHL1...3 (field supply)
Maximum water volume
Use the following graph to determine the maximum water volume for the
calculated pre-pressure.