Mitsubishi Electric EHWT17D-MHEDW, Data Book

Page: 35 / 131

7.6.7 Ambient Loop Pipe Work
Pipework Connections
Connections to the heat pump unit should be made using
the 22 mm compression as appropriate.
When connecting Ambient Loop pipes using compression
fittings, insert copper liner for Ambient Loop pipe (accessory
parts) into the pipes and tighten them from 0.75 to 1.25
turns.
Do not over-tighten compression fittings as this will lead to
deformation of the olive ring and potential leaks.
Note:
To weld the pipes in the field, cool the pipes on the heat
pump unit using wet towel etc.
Side Connections
It is possible to angle the ambient loop connections, for
connection to the side instead of top connection.
To angle out the connection:
1. Remove left side panel.
2. Cut the pipes to the desired length and angle the pipes in
the desired direction.
3. Make a hole on the panel.
4. Fit the panel
5. Connect the pipes
6. Please fill in the gap between panel and ambient loop
pipes with insulation
Notes:
• For side connection, the pipe diameter is 22.2 mm.
• Triangle marks on left side panel shows center of
ambient loop pipes.
• Noise from heat pump can be significant.
How to install PICV (Pressure Independent
Control Valve)
PICV should be installed on the Ambient loop pipe in order to
balance water or brine in Ambient loop.
Insulation of Pipework
• All exposed ambient loop pipework should be insulated to
prevent unnecessary heat loss and condensation. To
prevent condensate entering the heat pump unit, the
pipework and connections at the top of the heat pump unit
should be carefully insulated.
• Ambient loop inlet and outlet pipework should not be run
close together where possible, to avoid unwanted heat
transfer.
• Pipework between Local System2 and heat pump unit
should be insulated with suitable pipe insulation material
with a thermal conductivity of ≤ 0.04 W/m.K.
Filling the System (Ambient loop)
1. Check and charge expansion vessel.
If expansion vessel is used, close the valve under the
expansion vessel.
2. Check all connections including factory fitted ones are tight.
3. If you use filling pump, Connect the filling pump and return
line on the ambient loop system's filler connector.
4. Insulate all exposed ambient loop pipework.
5. Thoroughly clean and flush, system of all debris. (see
section 7.6.2 for instruction.)
6. Close the valve in the filler connector, open the valves on
the filler connector.
7. Fill heat pump unit's ambient loop with suitable sanitary
water or antifreeze solution mix.
When connecting metal pipes of different materials insulate
the joints to prevent a corrosive reaction taking place which
will damage the pipework.
8. Check for leakages. If leakage is found, retighten the nut
onto the connections.
9. Pressurise system to atmospheric pressure. Top up with
water as necessary.
10. Close the valves on the filler connector, Open the three way
valve in the filler connector.
11. If expansion vessel is used, open the valve under the
expansion vessel.
Sizing Expansion Vessels
Expansion vessel volume must fit the local system water or brine volume. Refer to the 7.6.3 water pipe work for details
Ambient loop flow rate range [L/min]
7.2 - 24.0
If the water or brine flow rate is less than 7.2 L/min, the flow rate error will be activated.
B-232
Water to Water Heat Pump (WTW)
7
Cylinder
unit/
Hydrobox/GSHP/WTW