8 | Piping installation
Installer reference guide
89
EPRA08~12EAV3+W1 + ETVH12SU18+23EA6V
Daikin Altherma 3 H MT F
4P644482-1 – 2021.03
Changing the pre-pressure of the expansion vessel should be done by releasing or
increasing nitrogen pressure through the Schrader valve of the expansion vessel.
a Schrader valve
8.1.5 To check the water volume: Examples
Example 1
The indoor unit is installed 5m below the highest point in the water circuit. The
total water volume in the water circuit is 100l.
No actions or adjustments are required.
Example 2
The indoor unit is installed at the highest point in the water circuit. The total water
volume in the water circuit is 250l.
Actions:
▪ Because the total water volume (250 l) is more than the default water volume
(200l), the pre-pressure must be decreased.
▪ The required pre-pressure is:
Pg = (0.3+(H/10))bar = (0.3+(0/10))bar = 0.3bar
▪ The corresponding maximum water volume at 0.3bar is 290l. (See the graph in
"Maximum water volume"[487]).
▪ Because 250 l is lower than 290 l, the expansion vessel is appropriate for the
installation.
8.2 Connecting water piping
8.2.1 About connecting the water piping
Before connecting the water piping
Make sure the outdoor and indoor unit are mounted.