Piping Connection Work; Checking The Water Circuit; Checking The Water Volume And Expansion Vessel Pre-Pressure - Daikin EBHQ006BAV3 Installation Manual

10. P
IPING CONNECTION WORK

10.1. Checking the water circuit

The units have a water inlet and water outlet for connection to a water
circuit. This circuit must be provided by a licensed technician and
must comply with all applicable legislations.
NOTICE
The unit is only to be used in a closed water system.
Application in an open water circuit can lead to excessive
corrosion of the water piping.
Before continuing the installation of the unit, beware of the following
points:
■
Two shut-off valves are delivered with the unit. To facilitate
service and maintenance, install one at the water inlet and one
at the water outlet of the unit.
■
Drain taps must be provided at all low points of the system to
permit complete drainage of the circuit. Two drain valves are
provided inside the unit.
■
Air vents must be provided at all high points of the system. The
vents should be located at points which are easily accessible for
servicing. An automatic air purge is provided inside the outdoor
unit. Check that this air purge valve is not tightened too much so
that automatic release of air in the water circuit remains
possible.
■
Take care that the components installed in the field piping can
withstand the water pressure (maximum 3 bar + static pressure
of the pump).
■
The maximum waterpiping temperature is 65°C according to
safety device setting.
■
Always use materials which are compatible with the water used
in the system and with the materials used in the unit.
■
Select piping diameter in relation to required water flow and
available external static pressure (ESP) of the pump. The
recommended water piping diameter is 1".
■
The minimum required water flow for the unit operation is
12 l/min. When the water flow is lower than this minimum value,
flow error 7H will be displayed and the operation of the unit will
be stopped.
NOTICE
It is strongly recommended to install an additional filter on
the heating water circuit. Especially to remove metallic
particles from the field heating piping, it is advised to use a
magnetic or cyclone filter which can remove small
particles. Small particles can damage the unit and will not
be removed by the standard filter of the heat pump unit.
10.2. Checking the water volume and expansion vessel
pre-pressure
The unit is equipped with an expansion vessel of 6 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 outdoor unit, is 10 l minimum.
Refer to "Technical specifications" on page 18
internal water volume of the outdoor unit.
INFORMATION
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.
EBHQ006+008BAV3
Unit for air to water heat pump system
4PW64602-1D – 12.2010
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. See example below.
The maximum allowed water volume is 250 l (if no glycol is
used). This is reduced to 175 l if 25% of propyleen glycol is
used.
In case no EKMBUHBA6V3 backup heater kit is installed, the
maximum allowed water volume is restricted to 150 l. In such
case we recommend the use of a thermostatic by-pass valve
(see example below).
As soon as the water circuit with the outdoor unit is in normal
operation range, this by-pass valve will gradually open, so the
entire circuit is than gradually heated.
Example
1
FHL1...3 Floor heating loop
2 Using the table below, determine if the expansion vessel
prepressure requires adjustment.
3 Using the table and instructions below, determine if the total
water volume in the installation is below the maximum allowed
water volume.
Installation
height
difference
≤ ≤ ≤ ≤ 7 m
to know the
>7 m
(a) Installation height difference: height difference (m) between the highest point of
the water circuit and the unit. If the unit is located at the highest point of the
installation, the installation height is considered 0 m.
2 3 4 5 6 7
M
6
1 Outdoor unit
2 Indoor unit
3 Heat exchanger
4 Backup heater
5 Pump
6 Shut-off valve
7 Motorised thermostatic by-pass valve
8 Collector (field supply)
9 By-pass valve (field supply)
T1...3 Individual room thermostat (optional)
M1...3 Individual motorised valve to control the floor heating loop
(field supply)
Water volume
≤ ≤ ≤ ≤ 170 l (with EKMBUH unit installed)
(a) ≤ ≤ ≤ ≤ 150 l (no EKMBUH unit installed)
No pre-pressure adjustment
required.
Actions required:
• pre-pressure must be
increased, calculate
according to "Calculating the
pre-pressure of the
expansion vessel"
• check if the water volume is
lower than maximum allowed
water volume (use graph
below)
8 9
T1 T2 T3
M1 M2 M3
FHL1
FHL2
FHL3
>170 l (with EKMBUH unit installed)
Actions required:
• pre-pressure must be
decreased, calculate
according to "Calculating the
pre-pressure of the
expansion vessel"
• 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.
Installation manual
11