Installation manual
16
EKHVH/X00 EKHVH/9WN
Daikin Altherma indoor unit
4PW64329-1 – 07.2010
Checking the water volume and expansion vessel pre-pressure
The unit is equipped with an expansion vessel of 10 litre which has a
default pre-pressure of 1 bar.
To assure proper operation of the unit, the pre-pressure of the
expansion vessel might need to be adjusted and the minimum and
maximum water volume must be checked.
1
Check that the total water volume in the installation, excluding
the internal water volume of the indoor unit, is 20 l minimum.
Refer to
"Technical specifications" on page 44
to know the
internal water volume of the indoor unit.
2
Using the table below, determine if the expansion vessel pre-
pressure requires adjustment and determine if the total water
volume in the installation is below the maximum allowed water
volume.
6.8.
Charging water
Calculating the pre-pressure of the expansion vessel
The pre-pressure (Pg) to be set depends on the maximum installation
height difference (H) and is calculated as below:
Pg=(H/10+0.3) bar
In most applications this minimum water volume will have a
satisfying result.
In critical processes or in rooms with a high heat load
though, extra water volume might be required.
NOTICE
When circulation in each space heating loop is controlled
by remotely controlled valves, it is important that this
minimum water volume is kept even if all the valves are
closed.
Example
1
Outdoor unit
2
Indoor unit
3
Heat exchanger
4
Backup heater
5
Pump
6
Shut-off valve
7
Shut-off valve
8
Collector (field supply)
10
By-pass valve (field supply
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)
FHL1
FHL2
FHL3
M1
T1
M2
T2
M3
T3
6
4
3
2
1
7
8
10
5
Installation
height
difference
(a)
(a) Installation height difference: height difference (m) between the highest point of
the water circuit and the indoor unit. If the indoor unit is located at the highest
point of the installation, the installation height is considered 0 m.
Water volume
≤
280 l
>280 l
≤
7 m
No pre-pressure adjustment
required.
Actions required:
• pre-pressure must be
decreased, calculate
according to
"Calculating the
pre-pressure of the
expansion vessel" on
page 16
• check if the water volume is
lower than maximum allowed
water volume (use graph
below)
>7 m
Actions required:
• pre-pressure must be
increased, calculate
according to
"Calculating the
pre-pressure of the
expansion vessel" on
page 16
• check if the water volume is
lower than maximum allowed
water volume (use graph
below)
Expansion vessel of the unit
too small for the installation.
■
During filling, it might not be possible to remove all air
in the system. Remaining air will be removed through
the automatic air purge valves during first operating
hours of the system. Additional filling with water
afterwards might be required.
■
The water pressure indicated on the manometer will
vary depending on the water temperature (higher
pressure at higher water temperature).
However, at all times water pressure shall remain
above 1 bar to avoid air entering the circuit.
■
The unit might dispose some excessive water through
the pressure relief valve.
■
Water quality must be according to EU directive
98/83 EC.
Summary of Contents for EKHVH008BB6V3
Page 47: ...NOTES NOTES...
