Air-source heat pumps use the difference between outdoor air temperatures and indoor air temperatures to heat your home. Even at very low temperatures a heat pump is able to extract heat from outside air to use in heating your home.
Ambient air is free and widely available, and it is the most common heat source for Air-source heat pumps.
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Exhaust or ventilation air is a common heat source for heat pumps in residential and commercial buildings. The heat pump recovers heat from the ventilation air, and provides water and/or space heating. Some units are also designed to utilise both exhaust air and ambient air. |
ASHPs supply more energy than they consume. By extracting heat from the surrounding air, the heat energy released can be up to 4 times the energy required to power the equipment.
An ASHP system consists of a compressor and a carefully matched evaporator coil and heat exchanger. A refrigerant liquid which circulates within the system has a boiling point as low as minus 40°C and evaporates when absorbing heat from the outside air. It is possible to extract considerable heat from the air at temperatures as low as minus 15°C.
When a heat pump is set in cooling mode, it works in the opposite way, exactly like a refrigerator, taking the heat from the inside of the home and releasing it outside.
An air source heat pump is often used in conjunction with a back-up heating system. On average, air source heat pumps operate up to 70% of the heating season, with the auxiliary heating system carrying the balance.
Air source heat pumps can be used for a wide variety of applications such as cooling for lofts, restaurant kitchens and hotel plant rooms where the hot water can easily be used for other applications. They can provide hot water using waste heat in the air. By using waste heat, they can also remove heat from an area, such as a loft space, where it is not needed.
Although they are less efficient than ground source heat pumps, and likely to be more variable because air temperatures fluctuate both daily and seasonally. Even when the outside temperature drops, air source heat pumps can still produce 2-3 times as much energy as they use to run.
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But their major advantage is the fact that it doesn’t require any outside space in which to install one. An air source heat pump is simply attached to the outside of the building, which is ideal for apartment developments. This significantly reduces the installation costs when compared with a ground source heat pump. |
Carbon emissions are an ever increasing concern to global warming, an air source heat pump will save in excess of 2 tones of carbon per year compared to other forms of heating - producing 50% less than a gas boiler, and 72% less than an all electric system, taking into account the inefficiency of power stations and losses in the delivery of electricity.
Compared to electric resistance heating, an air source heat pump may save you up to 30% on your annual heating bill and operating cost for summer cooling is similar to central air conditioning
An air-source heat pump can often be installed in as little as half a day, with little disruption to your time and existing systems.
The ASHP market is a new and evolving market, which is receiving considerable interest. A number of systems are currently being installed across the Northwest.
Low Carbon Buildings Programme offers a £1,200 grant regardless of the size of the system.
Links for Further Information:
http://www.heatpumpnet.org.uk/ http://www.feta.co.uk/
http://www.heatpumpcentre.org http://www.claren.org.uk