Section 3: Installation Information Page 9
3.2 Heating System Design Criteria
Before continuing with the installation of the Aerona³ heat pump,
please spend a few minutes confirming the suitability of the heat
pump to your system. Failure to do so may result in poor performance
and wasted time:
• Has a room-by-room heat loss calculation been carried out?
• Is this system designed for mono or bivalent?
• If monovalent, total heating capacity?
• If bivalent, what is the load capacity of the heat pump?
• If bivalent, what is/are additional heat source(s)?
• Type of system design? - S-plan, S-plan plus
• Will a buffer be used?
• If yes, what is the capacity of the buffer?
• Has cavity wall insulation been installed?
• Has loft insulation of 270mm been installed?
• Have all system pipes been lagged correctly?
• Are the existing controls being upgraded?
3.2.1 System Design Criteria
A typical condensing oil or gas fired boiler operates with a flow
of 70°C and a return of 50°C, i.e. with a DT of 20°C. A heat pump
operates with a flow of between 30°C and 55°C with a DT of 8°C.
The design of any system in the UK is typically based on the following
parameters:
1. That the outside design air temperature can fall to -3°C or lower
2. The internal design temperature can be between 18-22°C
depending on the room concerned.
3. The heat pump operates at lower water temperatures than an oil
or gas fired appliance.
Designing a new system for use with a heat pump is straight
forward, assuming the insulation properties of the dwelling
meets or exceeds current Building Regulations and the lower
flow/return temperatures are taken into account in the selection
of the type and size of the heat emitters used.
While underfloor heating is the preferred heat emitter, a combination
of underfloor heating and radiators, or radiators only, works just as
efficiently. It is necessar y, however, to calculate the size of radiator
required accurately – if this is not done, the house will fail to reach the
target temperature and will be costly to rectify after the installation is
complete.
When tested to BS EN 14511, the heat output for an heat pump is
declared at the test conditions of 7°C outside air temperature and
35°C or 55°C water flow temperature.
At all other values of outside air temperature and water flow
temperature the actual heat pump output will vary, e.g. the heat
output will:
• decrease with lower outside air temperatures and increase
with higher outside air temperatures at any given water flow
temperature, and
• decrease with higher water flow temperatures and increase
with lower water flow temperatures at any given outside air
temperature
A back-up boiler can be added to the rated output of the heat pump.
Provided that the heat pump is sized correctly for the system, this
back-up heater will only compensate for any short fall in me eting
the heat load for the propert y below the minimum design air
temperatures.
3.2.2 Heat Emitter Sizing
For guidance on sizing heat emitters, e.g. radiators and/or underfloor
heating, refer to MCS Heat Emitter Guide (MCS 021).
3 Installation Information
3.1 Introduction
Grant Aerona³ heat pumps should be stored and transported
in an upright position. If not, then the heat pump MUST be
positioned in an upright position for at least four hours before
being operated.
NOTE
!
For the heat pump to operate satisfactorily, install it as outlined in this
installation manual.
• The Grant Aerona³ heat pump should only be installed by a
competent person.
• Before installing the heat pump, please read the following
installation information carefully and install the heat pump as
instructed.
• Be sure to follow the safety notices given.
• After completing the installation, check the product operates
correctly. Then, explain to the user about the operation and
maintenance requirements as shown in this manual.
• Be sure to install the heat pump in a suitable location that can
support the heat pump when filled. Installation in an unsuitable
location may cause injury to persons and damage to the heat
pump.
• Do not install in a position where there is any possibility of
flammable gas leakage such as from LPG cylinder around the
heat pump. Leaked flammable gas around the heat pump may
cause a fire.
• If the leaked refrigerant is exposed to fire, poisonous gas may be
produced.
• Connect the heat pump with the flexible hoses and valves
supplied, as described in this installation manual.
• Do not use an extension cable.
• Do not turn on the power until all installation work is complete.
• Only use correct Grant UK parts and accessories to avoid
accidents such as electric shock, fire and leakage of water.
• Never touch electrical components immediately after the power
supply has been turned of f as electrical shock may occur. After
turning off the power, always wait five or more minutes before
touching electrical components.
• Be sure to connect the power supply cable correctly to the
terminal block as overheating can cause a fire.
• Ensure the wiring lid is fitted following installation to avoid electric
shock at the terminal block.
• Always connect the earth wire to the heat pump.
• Install a correctly rated circuit breaker.
• After installation, the heat pump and heating system must be
commissioned. Hand over all documentation to the end-user and
explain the operating functions and maintenance according to
these instructions.