6 Preparation
Installer reference guide
20
ERLQ004~008CA + 08S18CB
Daikin Altherma – Low temperature split
4P401676-1D – 2018.07
Minimum water volume
Check that the total water volume in the installation is minimum
10 litre for 08 and 20 litre for EHVZ16, the internal water
volume of the indoor unit NOT included. Do
NOT
split up the
minimum water volume over the 2 temperature zones.
It is sufficient to foresee the minimum water volume on the main
zone. In case of underfloor heating, this is easily done by 1 floor
heating loop that never will be closed by a (remotely) controlled
valve.
It is NOT required to foresee the minimum water volume on the
additional zone.
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.
T1
M1
T1
M1
T2
M2
T3
M3
M
FHL1
FHL2
FHL3
M2
M3
T2
T3
HPC1
HPC2
HPC3
a
b c
g
h
f
d
e
i
i
h
h
h
j
j
a
Outdoor unit
b
Indoor unit
c
Heat exchanger
d
Backup heater
e
Motorised 3‑way valve (mixing the main zone)
f
Additional pump
g
Main pump
h
Shut-off valve
i
Collector (field supply)
j
By-pass valve (field supply)
FHL1...3
Floor heating loop (field supply)
HPC1...3
Heat pump convector (field supply)
T1...3
Individual room thermostat (optional)
M1...3
Individual motorised valve to control loop FHL1...3 and
HPC1...3 (field supply)
Maximum water volume
Use the following graph to determine the maximum water volume for
the calculated pre-pressure.
0.3
0.5
1
1.5
2
2.5
100
50
0
10
150
200
250
300
350
400
450
a
b
a
Pre-pressure (bar)
b
Maximum water volume (l)
Example: Maximum water volume and expansion vessel pre-
pressure
Installation
height
difference
(a)
Water volume
≤280 l
>280 l
≤7 m
No pre-pressure
adjustment is required.
Do the following:
▪ Decrease
the
pre-
pressure according to
the required installation
height difference. The
pre-pressure
should
decrease by 0.1 bar for
each metre below 7 m.
▪ Check if the water
volume
does
NOT
exceed the maximum
allowed water volume.
>7 m
Do the following:
▪ Increase
the
pre-
pressure according to
the
required
installation
height
difference. The pre-
pressure
should
increase by 0.1 bar for
each metre above 7 m.
▪ Check if the water
volume
does
NOT
exceed the maximum
allowed water volume.
The expansion vessel of
the indoor unit is too
small for the installation.
In this case, it is
recommended to install
an extra vessel outside
the unit.
(a)
This is the height difference (m) between the highest point
of the water circuit and the indoor unit. If the indoor unit is
at the highest point of the installation, the installation height
is 0 m.
Minimum flow rate
Check that the minimum flow rate (required during defrost/backup
heater operation) in the installation is guaranteed in all conditions on
each zone separately.
NOTICE
When circulation in each or certain space heating loops is
controlled by remotely controlled valves, it is important that
the minimum flow rate is guaranteed, even if all valves are
closed. In case the minimum flow rate cannot be reached,
a flow error 7H will be generated (no heating or operation).
Minimum required flow rate during defrost/backup heater
operation
04+08 models
12 l/min
16 model
15 l/min
See the recommended procedure as described in
"9.4 Checklist
during commissioning" on page 61
.
6.4.4
Changing the pre-pressure of the
expansion vessel
NOTICE
Only a licensed installer may adjust the pre-pressure of the
expansion vessel.
When changing the default pre-pressure of the expansion vessel
(1 bar) is required, take following guidelines into account:
▪ Only use dry nitrogen to set the expansion vessel pre-pressure.
▪ Inappropriate setting of the expansion vessel pre-pressure will
lead to malfunction of the system.