The owner of this large ‘hard-to-heat’ detached property wanted to
combine the convenience of a high temperature air source heat pump with
the low fuel cost offered by a large boiler stove. The heat pump provides
background heat, while the boiler stove is used to match peak heating
We connected a Daikin Altherma split unit heat pump with the indoor unit
in the basement. This unit is capable of supplying 12kW of heat to the
existing central heating system (wall mounted radiators) at up to 80°C.
We installed a 30kW Woodfire RX inset boiler stove into an existing brick
fireplace. This is connected via a Termovar charge control pump to three x
400 litre buffer tanks also in the basement. Multiple buffer tanks had to be
used because of space constraints in the basement. When the stove is in
use the buffer tanks are configured to provide 1200 litres of buffer
capacity. However if the heat pump is operating then the storage
automatically reconfigures itself to use only 400 litres of buffer capacity.
We have been able to retain the existing oil-fired boiler to provide backup
heating, if required.