Air to Water Heat Pumps for Domestic Use
Air source heat pumps absorb heat from the outside air. This heat can then be used to heat radiators, underfloor heating systems, or warm air convectors and hot water in your home.
An air source heat pump extracts heat from the outside air in the same way that a fridge extracts heat from its inside. It can get heat from the air even when the temperature is as low as -15° C. Heat from the air is absorbed at low temperature into a fluid. This fluid then passes through a compressor where its temperature is increased, and transfers its higher temperature heat through heat exchangers to the heating and hot water circuits of the house.
Heat pumps have some impact on the environment as they need electricity to run, but the heat they extract from the ground, air, or water is constantly being renewed naturally.
Benefits of Heat pumps
• Lower fuel bills if certain circumstances, especially if you are replacing conventional electric heating
• Potential income through the UK government’s Renewable Heat Incentive (RHI)
• Capable of reducing running costs and CO2 emissions
• No fuel deliveries needed
• Can heat your home as well as your water
• Minimal maintenance required
• Helps achieve renewable energy targets
• Easy to design, install and maintain
• Fully scalable and can work independently or in conjunction with other systems
For every 1kW of electricity fed into a heat pump unit, you could get at least 3kW of heating energy. The overall system efficiency and energy savings will depend on the comparison with your current heating system, satisfactory system design and installation, and operational settings and how the system is set up and used
Unlike gas and oil boilers, heat pumps deliver heat at lower temperatures over much longer periods. During the winter they may need to be on constantly to heat your home efficiently. You will also notice that radiators won't feel as hot to the touch as they might do when you are using a gas or oil boiler.
Type of Air to Water Heat pumps
This system consists of outdoor heat pumps, which connects directly via water pipework to the internal hot water tank. From the tank water is then distributed to the hot water and heating circuits as per any conventional system.
This system combines an outdoor Heat pump which is connected via refrigerant pipework to the heat exchanger located internally; this then connects to a Hot water tank in the same way.
How do I decide if I need a Mono Block or Split type?
1) Capacity, Split type is available in larger sizes due to the heat exchangers been separate.
2) If you use a mono bloc you need to run water pipework from inside to outside and to ensure the water within the system does not freeze. As there is a risk of damage if this happens. With a split type there is only refrigerant in the system and all water is contained in the internal heat exchanger, reducing the risk of freezing
3) Mono Bloc are more common as they are easier to install and your local trained plumber can do this rather than requiring the services of an F Gas qualified refrigeration engineer to install the refrigeration pipework associated with a split type system
4) Mono bloc systems take up more room externally.
Note: It is legal requirement that anyone working on a Heat pump refrigeration circuit must have F Gas Certification.