Checking The Water Circuit - Daikin EDLQ036BA6VJU1 Manuel D'installation

Checking the water circuit

The units are equipped with 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 local laws and regulations.
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, check the following
points:
The maximum water pressure = 43 psi (3 bar) + static pressure
of pump.
The maximum water temperature is 149°F (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.
Take care that the components installed in the field piping can
withstand the water pressure and temperature.
Drain taps must be provided at all low points of the system to
permit complete drainage of the circuit during maintenance.
A drain valve is provided in the unit to drain the water from the
unit water system.
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 unit.
Check that this air purge valve is not tightened too much so that
automatic release of air in the water circuit remains possible.
Checking the water volume and expansion vessel
pre-pressure
The unit is equipped with an expansion vessel of 2.6 gallons (10 litre)
which has a default pre-pressure of 14.5 psi (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 unit, is 5.3 gallons (20 l)
minimum. Refer to "Technical specifications" on page 40 to
know the internal water volume of the unit.
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.
Installation manual
14
NOTE 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 2 3
1 Unit
2 Heat exchanger
3 Pump
4 Shut-off valve
5 Collector (field
supply)
6 By-pass valve
(field supply)
2 Using the table below, determine if the expansion vessel pre-
pressure 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 Water volume
height
≤
(a)
74 gallons (280 l)
difference
≤
23 ft
No pre-pressure adjustment
(≤
required.
7 m)
Actions required:
• pre-pressure must be increased,
calculate according to "Calculating
>23 ft
the pre-pressure of the expansion
(>7 m)
vessel"
• check if the water volume is lower
than maximum allowed water volume
(use graph below)
(a) Installation height difference: height difference (ft)(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 ft (0 m).
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 /32+0.3)x14.5 psi
(psi) (ft)
Pg =(H /10+0.3) bar
(bar) (m)
EDLQ036~054BA6VJU1 + EBLQ036~054BA6VJU1
I
4 5 6
T1 T2 T3
M1 M2 M3
FHL1
FHL2
FHL3
FHL1..3 Floor heating loop
(field supply)
T1..3 Individual room
thermostat (optional)
M1..3 Individual motorised
valve to control loop
FHL1 (field supply)
I User interface
>74 gallons (280 l)
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.
Unit for air to water heat pump system
4PW56182-1