How do air source heat pumps work?

Air source heat pumps harvest the sun’s heat from the air. A refrigerant circuit extracts heat as air is passed through the heat pump. We only use the highest quality air source pumps which are efficient enough to produce all your heating and hot water needs even when the air temperature outside is  -20°C. Some heat pumps can produce water at 75°C without any supplementary energy source.

Why are air source heat pumps so green and efficient?

Air source heat pumps are very efficient, with every unit of electricity used it can produce between 3 and 4 units of heat.
As they do not require collection loops or inside installation, air source pumps are an ideal solution where space is an issue. For the same reasons they typically carry a lower cost of installation than ground source.
Because such a high proportion of the heat output from a heat pump comes from a sustainable environmental source, CO2 emissions are substantially lower than traditional fossil fuel systems. This helps to reduce your carbon emissions and save the planet

Can a heat pump work on my existing home?

Stiebel Eltron PDF on Air Source Heat Pumps  ASHP brochure the heat is there

The benefits of using a Stiebel Eltron air source heat pump (ASHP) installed by Total NRG

  • Our expertise in the design & installation
  • Our ASHP will work down to -20°C still giving you 65°C without the need for a immersion heater, unlike some other heat pumps.
  • The quietest heat pump on the market, as low as 51dBa
  • Reduced fuel bills, especially if you are replacing oil, coal, LPG or direct electric
  • Not reliant on fuel deliveries
  • Protection from fossil fuel cost inflation
  • Can supply all your hot water and heating demands all year round
  • Life span up to 25 years
  • Reduced carbon emissions
  • Very low maintenance, no need to have regular flue services etc.
  • Have a return of investment from the Renewable Heat Incentive (RHI)

Is an air source heat pump (ASHP) suitable for my home?

Older homes which have been refurbished with modern levels of insulation or new build houses are ideal candidates for heat pumps. However it is possible to design effective systems for older, poorly insulated properties, but special care needs to be taken in the system design (perhaps using an existing boiler in tandem for the coldest few days of the year) and upgrades to your radiators may be necessary. We have experience designing and installing successful heat pump systems in listed and heritage properties and can advise you on your options. If you are replacing an LPG or oil heating system on an older property then there are substantial financial benefits from fuel savings, and RHI payments to be made.

Do you have somewhere to put it?

For a typical outside installation you will need a space with plenty of clearance for air flow. The unit does not need to be positioned immediately adjacent to the building.
We also supply a range of air source heat pumps that can be installed internally if planning constraints apply or it is your aesthetic preference.


What is a buffer tank for?

For fault-free operation, heat pumps require a minimum flow rate of heating water. We recommend using a buffer cylinder in order to ensure trouble-free heat pump operation. Amongst other things, buffer cylinders provide hydraulic separation between the heat pump circuit and the heating circuit. For example, if the flow rate in the heating circuit is reduced via thermostatic valves, the flow rate in the heat pump circuit remains constant.

For air source heat pumps the need for a buffer is even greater than for ground source pumps. The heat exchanger in air source pumps runs much colder than ambient temperatures, and as a result it becomes frosted with ice. Air source pumps must periodically work in reverse to defrost the exchanger. A buffer tank provides a source of heat to steal for this purpose, without robbing heat from the property being heated. Without this dedicated store of heat, an air source machine can start to take heat from a house, actually reducing the temperature of the property in a downward cycle.

Heat pumps, like cars, are less efficient if they start and stop frequently. Buffer tanks allow a pump to run for longer periods of time increasing efficiency. If a single room calls for heat it can use energy stored in the buffer tank first, delaying the need to start the pump again.