Air Source Heat Pumps
How do they work?
An air source heat pump (ASHP) is a heating system that extracts heat from the outdoor air and transfers it indoors to provide heating for a property. It works by utilising the principles of refrigeration to absorb heat from the air and deliver it at a higher temperature suitable for heating purposes. Here's how an ASHP works for a UK homeowner looking to install a new heating system:
1. Outdoor Unit: The ASHP consists of an outdoor unit, typically installed on an external wall or ground-mounted in the vicinity of the property. This unit contains a fan and a refrigeration system.
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2. Heat Absorption: The fan draws in air from the surrounding environment. Even at low temperatures, there is heat energy present in the air. The ASHP's refrigeration system contains a liquid refrigerant that absorbs this heat energy from the outdoor air.
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3. Refrigerant Circulation: The absorbed heat causes the refrigerant to vaporize into a gas form. The gas is then compressed by a compressor within the outdoor unit, increasing its temperature.
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4. Heat Exchange: The heated refrigerant gas passes through a heat exchanger known as the condenser. In the condenser, the hot gas releases its heat energy to a water-based central heating system or directly to the home's underfloor heating or radiators.
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5. Expansion Valve: After releasing its heat, the refrigerant returns to a liquid state and passes through an expansion valve, which reduces its pressure. This prepares the refrigerant to repeat the cycle of heat absorption from the outdoor air.
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6. Indoor Distribution: The heated water or air is then distributed throughout the home, providing warmth and comfort. It can be circulated through radiators, underfloor heating systems, or even air handling units, depending on the specific heating system setup.
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7. Optional Hot Water: Some ASHPs can also provide domestic hot water by incorporating a separate hot water cylinder or utilising a heat pump with a built-in hot water tank. This allows homeowners to have a combined heating and hot water system.
ASHPs are an energy-efficient heating solution, particularly in moderate climates like the UK, where outdoor air temperatures seldom reach extreme lows. They can extract heat from the air even when temperatures are below freezing, though their efficiency decreases as temperatures drop. ASHPs are an attractive option for UK homeowners looking to install a new heating system as they offer reduced energy consumption, lower carbon emissions, and potential cost savings compared to traditional heating systems like gas boilers or electric heaters.
Benefits of installing an air source heat pump?
Energy efficiency
ASHPs are highly efficient heating systems. They extract heat energy from the outdoor air and deliver it indoors, providing heating without relying solely on electricity or fossil fuels. For every unit of electricity used to power the ASHP, several units of heat energy are generated, resulting in lower energy consumption and reduced heating costs.
Reduce energy bills
ASHPs can help homeowners save on heating costs. While the initial installation cost may be higher compared to traditional heating systems, the long-term savings on energy bills can offset this investment. Additionally, ASHPs can qualify for government incentives and grants in the UK, such as the Renewable Heat Incentive (RHI), which further enhances the financial benefits.
Low maintenance
ASHPs generally require minimal maintenance. Regular inspections, filter cleaning or replacement, and occasional checks of the refrigerant levels are typically sufficient to keep the system running optimally. Additionally, ASHPs have a long lifespan, providing reliable heating for many years with proper care.
Increase property value
Installing an ASHP can enhance the value and marketability of a property. Energy-efficient and environmentally friendly features are increasingly sought after by buyers, making an ASHP an attractive selling point for homeowners in the UK.
