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What the Unit Comes With and What You Will Need
What the Unit Comes With and What You Will Need
Diverter valves
Hitachi use a 3-port valve to convert from heating to hot water
Heat meters
If you are using more than one heat source, heat pump + boiler you MUST measure the heat
produced by the heat pump and the electricity used. This is essential for RHI. The heat meter
goes in the return to the heat pump with a sensor in the flow. The electricity meter must
measure only the power consumed by heat pump. See hybrid drawings.
The Cylinder
If you want to heat water with a heat pump you need a dedicated heat pump cylinder. These
are 600mm diameter and are pre-insulated and can store water at up to 3 bar pressures.
Note the size and weight of the cylinder. Full installation instructions will be included with
the cylinder.
Ideally Cylinders should only be used IF the coil area is more than 2.5m
2
. Smaller coils give
very long recovery times and increase usage of the immersion heater. Cylinders can be
pressurised or open vented. We can work out the run cost for you if you tell us the coil size.
Below is a list of the components you will need to buy for each of the systems:
Flexible hoses
we recommend flexi hoses are used on Monobloc systems, they are not required on the split
systems. The water connections to all units are 1 inch BSP female up to size 4 and 1 1/4 on
the 5 and 6 units. We recommend connecting the water pipework with flexible hoses for ease
of maintenance and to avoid any vibration from the unit going into the house. All external
pipework has to be insulated to meet MCS standards.
Mounting feet
the outdoor units need to be mounted 100mm above the ground, we recommend using
rubber feet with unistrut channel. These come with mounting bolts included. Splits have 2
feet, monos have 3 feet
An expansion vessel, pressure gauge, pressure relief valve and filling loop
All Hitachi units have an expansion vessel inside.
Pump
The Hitachi units have a 7.5m pump installed inside.
Assuming you use a low loss header for heating, 1x 3 port zone valves and 6 elbows, you can
run, measuring from the header to the heat pump
•
30 m separation on 22mm copper for the 2HP
•
30 m separation on 28mm copper for the 3HP
•
20 m separation on 28mm copper for the 4-6HP
•
Call for the 8 and 10HP
If your runs exceed this give us a call as you might need extra pumps.
Water Filter
The Hitachi units have a filter inside the units, if the unit is running on a dirty system an
additional filter might be a good idea.
Glycol / anti-freeze
In Monobloc heat pumps the water goes outside the building. The unit can protect itself
from freezing up, but if the power goes off there is a risk that the unit will freeze causing
damage. To prevent this, we recommend putting propylene glycol mixture in the system. It
is important that the glycol concentration is adequate to protect the unit, if the unit freezes
up there will be no warranty. Manufacturer dependant, a mix of 25% is normal for UK
conditions.
Adding too much glycol is not a good idea as it increases the water pump power and slightly
reduces the capacity of your system.
Flow switch and flow meter
The Hitachi units have a flow meter and switch installed in the units.
