17 Air Source Heat Pump Tips

Air source heat pumps can be excellent heating and cooling appliances but work differently to other traditional heating systems such as gas.

Their installation and operation requirements can therefore differ from more commonplace heating systems and so it’s important to understand how an air source heat pump is setup, operated and maintained to help ensure you’re making the most out of one.

We’ve been using our own air source heat pump for over 5 years and so we’ve put together a complete list of tips for installing and running a heat pump in your home.

Our air source heat pump tips include:

  1. Get a home energy audit
  2. Have a heat pump professionally installed
  3. Keep the outdoor heat pump unit free of debris
  4. Change filters regularly
  5. Use smart controls for better efficiency
  6. Ensure a heat pump is suitably sized for a home
  7. Have the system serviced annually
  8. Keep the unit clean and well-maintained
  9. Reduce heat loss by insulating your home
  10. Set and monitor the correct pressure for your system
  11. Invest in a good quality heat pump unit
  12. Choose an efficient air source heat pump model
  13. Pay attention to noise levels
  14. Be aware of the signs of a failing heat pump
  15. Get multiple quotes before you buy
  16. Ensure the internal heating setup is adequate
  17. Consider local energy prices and the best deals

We moved homes over 5 years ago from a house that had a gas central heating system to a new-build house that had an air source heat pump heating and hot water system installed.

Air Source Heat Pump

We go over the above tips for air source heat pumps in more detail below using our own heat pump as an example.

1. Get A Home Energy Audit

Air source heat pumps work differently to more conventional heating systems and deliver heat at a lower temperature. However, they heat over longer periods of time and release the heat more efficiently into a home.

In order for an air source heat pump (ASHP) to work effectively, a home must keep the heat in long enough for temperatures to sufficiently rise.

A home energy audit/assessment can therefore be essential in making the most out of an air source heat pump.

During an audit, a qualified technician will assess your home’s energy use, identify where your home is inefficient and recommend improvements.

It can be interesting to find out how your home may not be as energy efficient as it could be.

A number of relatively straightforward improvements, such as sealing air leaks and insulating walls and ceilings, could make a big difference to the effectiveness of an ASHP and also

energy bills.

When a home is more energy-efficient, a heat pump can be able to do its job more effectively.

If you’re thinking about having an air source heat pump installed, consider scheduling a home energy audit to fully understand the home improvements required to make the most out of a heat pump system.

An installer could also use this information to help produce a more accurate quote for installation.

As our air source heat pump was installed when our home was built, our house is up to modern standards in terms of insulation and keeping heat in. If installing an air source heat pump in an older home, a home energy audit can be much more important.

Air Source Heat Pump
An air source heat pump can work much more effectively when heat isn’t lost too quickly from a home

2. Have A Heat Pump Professionally Installed

Air source heat pumps can be a significant investment and so you’ll want to be sure that one is installed correctly. Hiring a qualified and experienced contractor to install an ASHP is the best way to ensure this.

A good contractor will take the time to assess your needs and recommend the best type of heat pump for your home. They will also ensure the unit is installed correctly and perform operation tests to ensure that it’s running as effectively as possible.

Air source heat pumps are complex systems, and even a small mistake during installation can lead to big problems down the road. It’s therefore always worth paying the extra to ensure that a heat pump is set up right.

Through having lived with an air source heat pump for over 5 years, we understand the complexity of a heat pump system, including the siting of the outdoor heat pump unit and the indoor heating apparatus as shown in the pictures below.

Air Source Heat Pump Side
The external air source heat pump units needs to be installed correctly and in the right location
Air Source Heat Pump Hot Water Tank
The associated indoor heating apparatus also need to be installed and set up correctly

3. Keep The Outdoor Unit Free Of Debris

The outdoor unit of an air source heat pump system sits outside a home and extracts heat from the air to use within a home.

To work effectively, each component within an ASHP system must be working efficiently. This includes the outdoor heat pump unit that forces air through to capture heat.

Sufficient airflow through an air source heat pump is vital for efficient operation, especially at lower outdoor temperatures such as in winter.

An outdoor heat pump therefore needs to be free of debris to work properly.

If you have vegetation growing near the unit that could affect airflow, ensure it’s trimmed back as and when required.

Additionally, clear away any leaves, twigs, or other debris that could block the unit’s airflow. For example, our heat pump is prone to getting leaves stuck in it.

Air Source Heat Pump Side
Debris can build up in a heat pump and reduce effectiveness

Following a periodic regime of clearing debris can help prevent issues arising from reduced efficiency caused by blockages.

4. Change Filters Regularly

One of the most essential cleaning and maintenance requirements for air source heat pumps is regularly changing the filters.

Dirty filters can lead to problems such as:

  • Decreased airflow
  • Reduced efficiency
  • Increased energy costs

Filters can be commonplace with air to air heat pump systems (compared to the air to water heat pump system like we have).

Filters may be found within the outdoor heat pump unit or within any indoor air handling units.

Air handling units may need filters cleaned frequently

The video below gives an indication on how filters can be cleaned/replaced.

See our article on air source heat pump maintenance for more information.

5. Use Smart Controls For Better Efficiency

To help save money on heating and cooling costs, consider investing in smart thermostats and controls as part of an air source heat pump system.

Such devices allow can you to program your heat pump to operate only when needed, which can help to reduce energy consumption.

Modern smart thermostats and controls are also convenient because you can often control them from your smartphone or other mobile devices.

Our heat pump system that provides both heating and hot water can be controlled by the central control panel shown below.

Air Source Heat Pump Control Panel
Our central control panel

As we have an air to water heat pump system (that works with central heating radiators and underfloor heating), each area on the lower floor of our home has its own thermostat that works with an associated underfloor heating system and allows temperatures to be controlled individually.

Air Source Heat Pump Thermostat
The thermostats for the underfloor heating

These thermostats link back to the valve controls for the separate underfloor heating systems.

See our article on air source heat pumps and underfloor heating for more information.

6. Ensure A Heat Pump Is Suitably Sized

An air source heat pump should be suitably sized for a home so that its power is being used effectively for its purpose.

If an outdoor ASHP unit is too small and under-powered, it may not be able to heat or cool your home effectively and be working overtime with increased energy usage. Similarly, if it’s too big, it can cycle on and off too much, also reducing its efficiency.

A qualified contractor will choose the correct size heat pump for your home. They will take into account the square footage of your home and other factors, such as the number of windows and the type of insulation you have.

For example, our 11.2kW air to water heat pump is suitable sized for our 5-bedroom house.

Air Source Heat Pump
Our ASHP is suitably sized for our house

The installer considered factors such as the size of our home, and its use for both heating and hot water.

7. Get Regular Maintenance Checks

One of the best ways to keep your heat pump in good working order is to get regular maintenance checks. A qualified contractor will inspect your heat pump and perform any necessary repairs or maintenance during these checks.

By having a heat pump serviced in line with the manufacturer’s recommendation, such as every year, it can help to keep your heat pump’s warranty within date. That way, if something goes wrong with the unit, you should still be covered.

Having the unit serviced by a qualified contractor at least once a year is typical. During these servicing appointments, the contractor will inspect the unit and make any necessary repairs.

See our article on air source heat pump servicing for more information.

Here are a few things the technician will do during a maintenance check:

  • Check the refrigerant level. The technician will ensure the refrigerant level is where it should be. If it’s not, they’ll add more to bring it up to the proper level.
  • Clean the coils. The technician may also clean the evaporator and condenser coils. This helps improve heat transfer and keeps the system running efficiently.
  • Lubricate moving parts. The technician may also lubricate all moving parts in your heat pump. This helps prevent wear and tear and keeps the system running smoothly.

The same video as earlier in this article highlights tips on how to take care of your heat pump:

8. Keep The Unit Clean And Well-Maintained

Although air source heat pump units are only electrically powered appliances, they should still be cleaned and maintained periodically to help keep them operating at full efficiency.

A manufacturer may specify any cleaning to be undertaken in between services, such as cleaning the coils.

Air Source Heat Pump Back
Cleaning an air source heat pump can help maximize performance

9. Help Reduce Heat Loss By Insulating

One of the best ways to help reduce heat loss in your home can be to bring home insulation levels up to a good standard. Doing so can help keep the heat in your home for longer, which in turn can help reduce the load on a heat pump.

Insulation requirements may be brough up as part of a home energy audit, but an installer may recommend insulation as part of a quote.

Several ways to insulate your home can include:

  • Adding insulation to your attic. Proper insulation is one of the most effective ways to reduce heat loss in your home. The U.S. Department of Energy recommends using at least R-30 insulation in your attic.
  • Weatherstripping and caulking. Sealing up cracks and gaps around doors and windows can also help reduce heat loss.
  • Installing storm doors and windows. Storm doors and windows provide an extra layer of protection against the elements.

10. Set & Monitor The Correct System Pressure

Understanding how to read a pressure gauge on an air source heat pump system will allow to you keep an eye on how a heat pump is operating and help identify any issues before they may arise.

We have a pressure gauge that we keep an eye on as part of our central heating system. If there are any issues with system pressure, we can consult our installer before there’s any problems with our heating or hot water.

Air Source Heat Pump Pressure Gauge
A pressure gauge for our heat pump heating system

An installer will be able to help you understand how to monitor your own heat pump system.

11. Invest in a Good Quality Heat Pump Unit

Air source heat pumps should be considered as a long-term investment into you home to help make them more cost-effective and their installation worthwhile.

By ensuring that a heat pump lasts for as long as possible, it can help the initial costs to be recuperated and savings to be achieved for a longer length of time.

If you’re looking for an air source heat pump that can give you years of trouble-free service, it’s therefore worth investing in a good quality unit if you can.

There are several high-quality brands that an installer may recommended. For example, ours is a Mitsubishi Electric air source heat pump and we haven’t had any issues with it in the 5+ years we’ve been using it.

Air Source Heat Pump

Here are a few things to look for in a heat pump:

  • Energy efficiency. Look for a unit with a high SEER (Seasonal Energy Efficiency Ratio) rating. The higher the SEER rating, the more energy-efficient the unit can be.
  • Quality compressor. The compressor is one of the critical parts of a heat pump as it helps to maximize the heat gains from outdoor air.
  • Look for a heat pump with a good warranty. A good warranty is another sign of a well-made, high-quality heat pump as the manufacturer can have more faith in the product.
  • Read customer reviews. Finally, don’t forget to read customer reviews before you make your purchase. That way, you can see what other people say about the unit you’re considering or one that an installer is recommending.

12. Choose An Efficient Model

While an efficient air source heat pump can be a sign of a good quality unit, efficiency is one of the most important factors of any heat pump.

Efficiency in extracting heat from outside air for use in a home can help make air source heat pumps competitive against other forms of heating systems such as gas.

Efficiency is the ability for an air source heat pump to deliver as much heat as possible from the least amount of electrical power used.

ASHP efficiency is typically referred to by the COP (Coefficient of Performance) for heating and EER (Energy Efficiency Ratio) for cooling. These numbers refer to efficiency at certain scenarios, while their seasonal counterparts (SCOP, SEER and HSPF (Heating Seasonal Performance Factor)) relate to efficiency over a season for a more accurate rating.

The higher the number, the greater the efficiency potential for an air source heat pump.

For example, our heat pump can reach a COP of over 4 in the most ideal conditions, meaning that it can produce 4 times the amount of heat energy for every 1 unit of electrical energy consumed.

Air Source Heat Pump Plate

Read our complete guide to air source heat pump efficiency for more information.

In the US you can look for a model certified by Energy Star. This government-sponsored program helps consumers protect the environment and save money at the same time by identifying energy-efficient products.

HVAC units equipped with the Energy Star label are tested and abide by strict energy efficiency guidelines. In addition to being more energy-efficient, Energy Star certified models tend to be quieter and have more extended warranties than non-certified models.

As a result, choosing efficient air source heat pumps such as Energy Star certified models is a great way to get the most out of your air source heat pump.

13. Pay Attention to Noise Levels

Air source heat pump units won’t typically make any noise when not in operation but will make some level of noise when working.

Noise will be produced by the fan(s) and compressor in an ASHP.

Air Source Heat Pump Fan
Noise can be made by fans in an air source heat pump

When an air source heat pump is having to work harder, such as in lower temperatures, noise can increase.

As a result, noise should be accounted for when choosing a location for an air source heat pump, and consider distance to neighboring properties.

When having an air source heat pump installed consider the noise levels produced by the external unit. Some models can be quieter than others and the maximum noise level is typically outlined by the manufacturer.

See our article on air source heat pump noise for more information, including a video of our own heat pump in operation.

14. Be Aware Of Signs Of A Failing Heat Pump

Like any other machinery, heat pumps can and do break down from time to time. It can be important to be aware of the signs of a failing heat pump so that you can fix the problem before it potentially becomes a more major issue.

Here are some common signs of a failing heat pump:

  • The system is providing reduced heat.
  • The system is providing reduced cooling.
  • Reduced or increased pressure in the system.
  • The outdoor unit is making different noises.
Air Source Heat Pump Tank

If you notice any of these issues, it’s always worth talking to a qualified technician to take a look at your heat pump.

From our experience air source heat pumps can have longer wait times for fixes and spare parts compared to more traditional heating systems and so staying aware for the signs of a failing heat pump system can be beneficial.

15. Get Multiple Quotes Before You Buy

Ensure that you’re get multiple quotes before buying an air source heat pump. That way, you can be sure you’re getting the best deal for a new heat pump system.

When you get multiple quotes, be sure to compare the following:

  • The prices of the units. In the first instance, you’ll want to compare the prices before making your purchase, but don’t just compare the upfront cost. You’ll want to also be sure to factor in the cost of installation and any ongoing maintenance costs.
  • The efficiency of the units. Higher HSPF and SEER rating can mean reduced running costs but this may be factored into the price of heat pump units.
  • The quality of the units. An installer should be recommending high quality heat pump units from reputable manufacturers so that the system can last for as long as possible.
  • The warranty. Compare the warranties of the units that are being offered.

16. Suitable Internal Heating Setup

While it’s important that the right size outdoor air source heat pump unit is chosen along with other factors such as good efficiency and build quality, the internal heating setup can be just as important to allow a heat pump to work as effectively as possible.

The internal setup of an ASHP system can depend on the type of air source heat pump; either air to air or air to water.

For air to air heat pump systems, the internal apparatus will typically consist of space heating equipment such as one of more air handling units, depending on whether a ducted or ductless setup is being used.

For air to water heat pump systems, the internal apparatus can consist of underfloor heating and radiators. Our ASHP is an air to water system and uses both.

Air Source Heat Pump Radiator
Our heat pump works with large surface area radiators for maximum efficiency

Air to water setups can also be used to provide domestic hot water when used alongside a hot water storage tank.

Air Source Heat Pump Water Heater Tank
A suitable hot water tank would be required to work with a heat pump

As heat pumps work at lower output temperatures compared to fossil fuel-burning heating systems, more importance is placed on this internal setup to release the heat as effectively as possible.

That’s why large surface area equipment such as underfloor heating and large radiators should be used with an air to water system.

If insufficient internal heating apparatus is used, it can reduce the effectiveness of an ASHP. If replacing an existing heating system with a heat pump then an installer may also recommended updating any older internal heating equipment.

16. Consider Local Electricity Energy Prices

Air source heat pump systems run on electrical power only and so if you’re switching from a gas heating setup then expect electricity bills to increase accordingly.

Electricity energy can often be more expensive than gas so it’s worth shopping around for the best energy prices when a heat pump is installed.

A heat pump will need to work harder in colder temperatures and electricity consumption can increase as a result.

Air Source Heat Pump

Further Reading

Parts Of An Air Source Heat Pump Explained

Pros & Cons Of Air Source Heat Pumps

Air Source Heat Pump COP Explained

Hybrid Air Source Heat Pumps Explained

Air Source Heat Pumps vs Gas Boilers

Air Source Heat Pump Electrical Requirements