Answer: Common air source heating problems include loss of heat production, lack of performance in freezing temperatures, noise, ineffectual location, and poor installation. These problems can be avoided by using a reputable installer.
Whilst Air Source Heat Pumps are a great renewable technology to supply your home with heat and hot water, if not properly designed and installed they can suffer from poor performance. Here, we hope to highlight some of the more common problems that can arise with Air Source Heat Pumps, and what to consider when planning your home’s energy efficient future.
What is an air source heat pump?
Simply put, an air source heat pump (ASHP) is a way to heat your home and provide you with hot water, just like a boiler. But instead of burning fossil fuels, ASHPs use a small amount of electricity to collect a large volume of low-grade heat from the air, transforming it into high-grade heat for your property.
While this sounds straightforward, when you look a little closer there are some complex processes occurring within the heat pump. Air is drawn into the heat pump using a fan and passed across a large heat exchanger. Inside the heat exchanger is a refrigerant which is very cold, and heat from the air is absorbed by the refrigerant.
The heat pump then uses a refrigeration cycle to compress the refrigerant, causing it to heat up, and this high-grade heat is then used to heat your home and hot water. In effect, it is the same system which keeps the space inside a fridge cold, but instead of removing heat from the freezer compartment and dumping it into the kitchen, a heat pump harvests heat from the environment and transfers it into your home.
Potential air source heating problems
As with most mechanical equipment, air source heat pumps can suffer failures from time to time. Problems with an ASHP, just like any heating system, can have a major impact on your home and quality of life, so it is important to be aware of them from the planning stages of your project.
Possible problems with ASHPs are:
1. Poor design
Nearly all problems with an air source heat pump system can be traced back to a poor initial design. If the designer/installer hasn’t undertaken suitable or accurate heat loss calculations for the building, properly designed the heat pump or the heating distribution system (ie underfloor heating, radiators etc) then it is likely that the system will operate poorly.
2. Poor installation
Poor installation of the heat pump unit and associated pipework play a big part in the efficiency and longevity of your unit. The use of incorrect or poor quality parts, and/or substandard workmanship will mean that your unit cannot run to its full potential. A quality installer will be certified with the Microgeneration Certification Scheme (MCS), use good quality products and parts, and will meet or exceed minimum installation standards as set out by the MCS..
Contact IMS Heat Pumps to work with experienced MCS-accredited professionals.
3. Freezing temperatures
Heat pumps are usually designed to operate at outdoor temperatures as low as -15C to -20C, but the choice of machine is critical to ensure it can provide enough power to keep your home warm. The location of your house and the height above sea level must be taken into account during the design stage.
A heat pump system designed in accordance with the Microgeneration Certification Scheme should provide 100% of your heating and hot water needs under design conditions for the locality.
However, even if the system is properly designed, during periods of heavy snowfall or prolonged sub-zero temperatures, your heat pump should be checked to make sure snow and ice don’t build up around the fan or heat exchanger.
4. Noise
Air source heat pumps are equipped with a large fan and a compressor, so during operation they do make an amount of working noise. However, strict planning standards apply for air source heat pumps to meet permitted development status; the sound level at the nearest assessment point (usually your neighbour’s window) must be 42dBA or less, roughly equivalent to the sound level inside a library.
Good quality modern air source heat pumps do have very low noise levels, so they can be located as close as 2m to the assessment point and still meet the 42dBA sound level. However, if you want a completely noise-free solution you might want to consider ground source heat pumps.
Also read: Air source heat pump manufacturer reviews
5. Appliance location
Installing your air source heat pump in the wrong place will likely cause problems later down the line. Sound level is one factor in choosing the right location for your air source heat pump, as you will need to make sure that the installation meets permitted development standards.
Another important consideration is that your heat pump is placed in an area with a plentiful supply of free air. It needs to be in an open, outdoor place with no barriers or obstructions that could cause the heat pump to recycle its cold, waste air which will have a negative effect on the performance and efficiency.
Additionally, having your unit located at a distance from your home (up to 20m maximum) will increase external pipework, which could result in heat loss unless a high quality pre-insulated flow/return pipe is used – foam lagging is not a suitable solution as unacceptable levels of heat loss will occur.
6. Kerb appeal
Another factor to consider when siting your pump is aesthetics. Not everybody appreciates the sight of an air source heat pump, so while modern, high quality units are considerably better-looking than older units, you might want to consider the location of the unit with regard to the kerb appeal and attractiveness of your property. Whilst having an energy-efficient heating system for your home is a plus point for potential buyers, it will help if it doesn’t look too intrusive.
Depending on where you live, and where on your property you plan to install the heat pump, you may need to seek planning permission.
7. Loss of heat production
As the primary function of an air source heat pump is to provide heating for your home, any major malfunctions are usually easy to detect, particularly if the weather is cold. Fortunately heat pumps are very reliable so mechanical failure is not common, but as with any machine an annual services should be undertaken to make sure your heat pump is running smoothly and effectively.
Failure of the electricity supply will also cause the system to stop working, though this is true of any heating system as circulation pumps require electricity to run.
Benefits of an air source heat pump
While of course it is important to be aware of the problems you can encounter with an ASHP, it is vital to understand their benefits too. We think air source heat pumps are a great addition to homes where their function has been properly thought out. Benefits of ASHPs include:
Low carbon emissions
By using just a small amount of electricity, which could come from a sustainable source such as solar PV or a ‘green’ electricity tariff, an air source heat pump will considerably reduce your home’s impact on the environment.
Energy efficient
If designed properly, air source heat pumps can deliver between 300% and 400% efficiency, meaning you will make the most of the energy you pay for. As with any heat source, the efficiency of the system will only be as good as your home’s energy performance, so before installing a new heat pump to an existing property, you may need to invest in insulating your home properly first.
Ease of use
Once installed and commissioned, you can leave the heat pump to do its thing. The onboard control computer uses a system called “weather compensation” to optimise its output in accordance to prevailing conditions, ensuring your home stays at a constant, comfortable temperature.
Heat distribution options
The heat produced by an air source heat pump can be distributed throughout your home using low temperature radiators and/or underfloor heating systems.
Small size
Most air Source Heat Pumps are only approximately 1m x 0.4m x 1.2m (WxDxH) for an average family home and take up much less ground space than a ground source heat pump, meaning they don’t have to make a huge visual impact and can be used for homes where outside space is at a minimum.
Cheaper to install
With an average installation cost staring at approximately £10,000, air source heat pumps are cheaper and easier to install than ground source heat pumps. However, there are other pros and cons to balance. Read our blog about ground source vs air source heat pumps to learn more.
Cheaper to run
Because of the very high operating efficiencies, heat pumps can offer considerable running costs. A well-designed, properly installed and correctly maintained heat pump could save you more than 50% on your heating costs compared to traditional heating methods.
Long life expectancy
With correct installation from qualified tradesmen and a schedule of annual servicing and maintenance, your ASHP has a lifespan of approximately 15years – much longer than most traditional boilers.
Financial incentives
Air source heat pumps are a renewable energy source covered by the Renewable Heat Incentive (RHI) which pays heat pump owners for the renewable heat they produce.
Summary
Air source heat pumps are an excellent source of heating and hot water for your home, with the added benefit of being a renewable energy system. As we hope you can see, the benefits of using an ASHP can hugely outweigh the problems, so long as your unit is the most suitable for the job in hand and is installed, maintained, and operated properly and effectively.
If you’re interested in having an air source heat pump installed, contact our friendly and experienced team with any queries, or request a quote directly on the IMS Heat Pumps website.