Formula To Calculate The Expansion Vessel Pre-Pressure; To Check The Water Volume And Flow Rate - Daikin Altherma EPGA16DAV3 Installer's Reference Manual

6 Preparation
▪ Air vents. Provide air vents at all high points of the system, which
must also be easily accessible for servicing. Two automatic air
purges are provided in the indoor unit. Check that the air purges
are NOT tightened too much, so that automatic release of air in
the water circuit is possible.
▪ Zn-coated parts. Never use Zn-coated parts in the water circuit.
Because the unit's internal water circuit uses copper piping,
excessive corrosion may occur.
▪ Non-brass metallic piping. When using non-brass metallic
piping, insulate the brass and non-brass properly so that they do
NOT make contact with each other. This to prevent galvanic
corrosion.
▪ Valve – Change‑over time. When using a 2-way valve or a 3-way
valve in the water circuit, the maximum change-over time of the
valve must be 60 seconds.
▪ Domestic hot water tank – Capacity. To avoid stagnation of
water, it is important that the storage capacity of the domestic hot
water tank meets the daily consumption of domestic hot water.
▪ Domestic hot water tank – After installation. Immediately after
installation, the domestic hot water tank must be flushed with fresh
water. This procedure must be repeated at least once a day the
first 5 consecutive days after installation.
▪ 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.
▪ 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
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
a b
d
a Recirculation connection
b Hot water connection
c Shower
d Recirculation pump
6.3.2 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)
6.3.3

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 20
litres, the internal water volume of the outdoor unit NOT included.
Installer reference guide
20
accordance with the applicable
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.
a b c d e h h
M
f g h
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 Overpressure bypass valve (delivered as accessory)
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
NOTICE
The maximum water volume depends on whether glycol is
added to the water circuit. For more information on the
addition of glycol, refer to
against freezing" on page 29.
Use the following graph to determine the maximum water volume for
the calculated pre-pressure.
A
2,4
2,1
1,8
1,5
1,2
1
0,9
0,6
0,3
20 70 120
140
A Pre-pressure (bar)
B Maximum water volume (l)
Water
Water + glycol
Example: Maximum water volume and expansion vessel pre-
pressure
EPGA11~16DAV3 + EAVZ16S18+23DA6V+9W
i j
T1 T2 T3
M1 M2 M3
HPC1 HPC2 HPC3
i
T1 T2 T3
M1 M2 M3
h
FHL1
FHL2
FHL3
"7.5.6 To protect the water circuit
170 200 220 270 320
B
Daikin Altherma – Low temperature split
4P556075-1 – 2019.02