Air Source Heat Pumps
Air Source Heat Pumps
Air source heat pumps extract free heat energy from the air, using electricity. Unlike gas and oil boilers, they’re a low-carbon alternative.
An outdoor unit connects with refrigerant-filled tubing to an indoor air handler. When liquid refrigerant passes through the outdoor coils it absorbs ambient heat, changing from its colder liquid state to a warmer gas state.
Cost
Air source heat pumps cost a little more to purchase and install than other types of heating systems, but they save money in the long run through lower energy costs. You may also be eligible for rebates or tax credits. The most cost-effective model will depend on the climate in your area. Ask friends and neighbors about their experiences with heat pump installers, or seek out referrals from local green-energy resource groups. It’s best to get price quotes from multiple contractors.
Efficiency levels for heat pumps are measured by the Coefficient of Performance (COP). The higher the COP, the more efficient the machine. Look for models that are rated to perform well in cold climates, as these will be able to extract the most thermal energy from colder outdoor temperatures. You should also check the cooling and heating seasonal energy-efficiency ratings, which are often given as SEER and HSPF respectively.
Since a heat pump doesn’t burn fossil fuel, it doesn’t release carbon dioxide or other pollutants into the atmosphere. In fact, switching to an air-source heat pump from a gas or oil boiler could cut your carbon footprint by up to 44% a year.
Efficiency
Air source heat pumps use electricity to transfer energy between indoor and outdoor air temperatures to provide space heating and hot water. In heating mode, the system extracts low-temperature heat from outdoor air and delivers it to the home; in cooling mode, it reverses direction and expels warm air outdoors, leaving colder air in its place. Depending on the size of the system and the energy used to operate it, a centrally-ducted air source heat pump can deliver up to four units of useful energy for every unit of electrical energy it consumes. Multi-head ductless mini-split systems are also available for homes or buildings without traditional ducting.
Because they move rather than generate energy from fuel, ASHPs are typically more efficient than combustion heating appliances like electric furnaces and electric baseboard heaters. In fact, the best models can deliver up to three times as much heat energy as they consume in electrical power.
However, their efficiency will drop as the outdoor temperature air source heat pump drops — because it takes more work to extract heat on colder days. This effect is minimized in regions that rely on renewables for their electricity production, such as wind and hydropower.
Installation
Air source heat pumps (ASHP) use electricity to move heat between indoor and outdoor air. They are a renewable energy technology that, if properly specified and maintained, can offer a cost-effective solution to heating a home or commercial property. ASHPs also provide domestic hot water and can replace traditional gas boilers.
The installation process of a new system is relatively straightforward. An engineer will visit your home or business to conduct a full inspection and recommend an appropriate type of ASHP to meet your requirements. Depending on the size and insulation of your building, the amount of heating you need and how often it will be used, an engineer will advise on the ideal system to suit your needs and provide an indication of the savings that you can expect.
If you choose a ducted system, the ASHP will have an outdoor unit connected to one or more indoor units (or “heads”) via refrigerant lines. The indoor heads are then ducted through the house and distributed by a blower. This is a popular option for homes without existing ductwork, or for homeowners who want to add a ducted system to an older home with no ductwork.
When choosing an installer, ask friends and family for recommendations or consult a green-energy resource group in your area. It’s important to find a contractor who’s familiar with the technology and can help you access utility rebates and state incentives.
Maintenance
An air source heat pump works by drawing in warm air from outside a property and compressing it to boost its temperature. This is then transferred to the heating system and can provide hot water to every room in the home. These systems are also efficient sources of hot water for homes without access to mains gas.
Annual preventative maintenance helps an air source heat pump to operate at peak efficiency throughout the year, minimising breakdowns and resulting in cost-savings for the homeowner. Different types of heat pumps have slightly different maintenance requirements, but all require regular cleaning and annual checks to make sure everything is working correctly.
As part of a maintenance visit the technician will check the heat pump’s electrical systems for the correct operation of relays and other components. They will also examine the external unit to ensure it is securely bolted down to the ground or wall, and that it sits air source heat pump on anti-vibration mounts if required. The condenser fan motor will be lubricated to help keep it running quietly and efficiently. A full blown diagnostics check will be carried out and the heat pump’s refrigerant levels checked and topped up as necessary.
Neglecting heat pump maintenance will result in higher energy bills and a reduced lifespan for the unit. The good news is that a good warranty will lower your out-of-pocket costs for maintenance and repair work over the years.