Best of both worlds

Best of both worlds

When an ageing boiler needed to be replaced, the homeowner opted to install a new hybrid system to provide enhanced performance and comfort as well as cost savings.

Best of both worlds
Keith Arkwright

Keith Arkwright, who lives in Yate, near Bristol, has chosen a Daikin Altherma hybrid heat pump solution to provide his family with a warm, comfortable home and to save him money on his energy bills.
The Daikin system combines a gas condensing combi boiler and an air-to-water heat pump to create a highly energy-efficient and cost-effective domestic heating and hot water system that is an ideal gas boiler replacement.
Energy bills for the three bedroom, semi-detached house had increased substantially since a conservatory, extra shower rooms and a hot tub had been added – despite solar PV panels being installed to offset the additional running costs and to help offset its carbon emissions.
When the efficiency of the previous 24kW gas boiler system began to fall, Keith contacted his energy supplier with whom he had an annual maintenance contract. However, the engineer explained that the company could not supply spare parts any longer and, as the boiler was more than ten years old, a new one could not be fitted under the maintenance contract.
This meant that Keith had to look for an alternative solution. He looked at a number of heating options, including standard gas boilers and renewable systems, and eventually decided to opt for the new Daikin Altherma hybrid heat pump system.
Keith believes he now has the best of both worlds.
“We have a highly efficient gas boiler for when it is very cold outside and an air-to-water heat pump – plus the system can also be used to provide hot water. For the first time, I am now in credit with my energy supplier after the winter. Normally I am in debt and having to play catch up by spring.”
Daikin’s system has two settings for heating – ecological or economical. In the ‘ecological’ setting, the system is set to limit carbon emission rates, potentially saving the Arkwright family one tonne of carbon every year.
In the ‘economical’ setting, the smart controller automatically searches for the most economical operating conditions to deliver the lowest running costs, based on the household’s electricity and gas tariffs, ambient conditions, heat load and leaving water temperature.
At higher outdoor temperatures, when the heat pump has sufficient capacity to cover the heat load, it will operate alone. As temperatures fall, the boiler starts to support the heat pump in hybrid mode, only taking over on the coldest days, when using the heat pump becomes less cost efficient.
Daikin’s unique and patented system comprises a heat pump and boiler working in series rather than in parallel. This means that in hybrid mode, heating water is pre-heated by the more efficient heat pump, reducing the energy consumed by the boiler. In ‘economical’ mod,e up to 35% higher heating efficiencies can be achieved over a gas condensing boiler alone, saving a substantial amount of energy, with lower fuel bills as a result.
The system has a heating capacity of 27kW and hot water capacity of 33kW. The design flow temperature of water through the system is 65°C when the temperature is -7°C outside, which means that the existing radiators and pipework did not need to be replaced. When the external temperature reaches 18°C, the design flow temperature is 43°C.
The installation was carried out by Otter South West Ltd of Taunton. The indoor unit fits in the same space as a standard gas boiler and can be connected to existing radiators and pipes, so it is fast and simple to install, causing minimal disruption.
Colin Richards, the company’s director, highlighted that there were no problems with the installation as being a major advantage for the new system.
“The installation was very similar to a two-part storage combi, with the hydrobox and wiring centre mounted on the wall and the gas boiler fitted to the front. The process was very easy, with a new controller for simple set-up and commissioning.”
The Daikin Altherma hybrid heat pump provides the Arkwright household with the best of two proven technologies and one of the most affordable renewable energy sources available. It is considered as the heat source of the future: environmentally-friendly, able to cope with the complexities of energy mix and supply, while remaining easy to operate and ensuring comfort for end-users.