Air Source Heat Pumps: A Complete Guide (2023)

Are you considering installing an air source heat pump? Or are you wondering what an air heat pump costs? Find out everything you need to know about this low-carbon heating alternative.

Have you already decided on an air/water heat pump?

Get an air source heat pump

What is an air source heat pump?

Air Source Heat Pumps: A Complete Guide (1)

Most home heaters either burn fuel or convert electricity to heat. But heat pumps are different because they don't generate heat.

Instead, they transport existing thermal energy from outside into your home. This makes them more efficient. This is because they provide more heat energy than they consume electrical energy. So a heat pump system can cost less than a traditional fossil fuel heating system.

Would likelearn more about air source heat pumps?No problem. Watch our short video and find out how heat pumps

  • userenewable energy
  • Aremore efficientas a gas boiler (400% efficiency)
  • Arecost efficient
  • reduce your carbon footprint
  • Arequiet
(Video) Guide to Air Source Heat Pumps | EXPERT ADVICE | Homebuilding

How does an air source heat pump work?

An air source heat pump works in a similar way to aFridge in reverseto heat your home. This is how it works:

Air Source Heat Pumps: A Complete Guide (3)
  1. Outside air is blown through a pipe network filled with refrigerant. As a result, the refrigerant is heated and turns from a liquid into a gas.

  2. This gas flows through a compressor, which increases the pressure. The compression also adds more heat - similar to how the air tube heats up when you add air pressure to your tires.

  3. The compressed hot gases enter a heat exchanger surrounded by cool air or water. The refrigerant transfers its heat to this cool air or water and heats it up. And this is circulated in your home to provide heating and hot water. Meanwhile, the refrigerant condenses back into a cool liquid and begins the cycle again!

Using an air source heat pump at home

Air source heat pumps can be used to heat your home and water. Here are a few things to consider.

It is heated with an air heat pump

Heat pumps work best when they existless difference between inside and outside temperature. Just like your fridge has to work harder in hot weather.

This makes them a good match forunderfloor heating systems. Floors cover a much larger area than radiators, so they don't have to get as hot to provide the same amount of heat.

Air source heat pumps also have a lower output than a gas or oil boiler. As a result, they cannot give off heat as quickly. Instead, they are best used to slowly heat up your home over an extended period of time.

Air source heat pump and radiator

If you have radiators in your home and are switching from gas heating to an air source heat pump, you will probably need to buy somelarger radiatorsto keep your home warm.

Using an air source heat pump for hot water

heat pumpscan also be a great source of hot water - but the water is cooler than from a boiler. In practical terms, when you run a bath, you need more hot water and less from the cold tap. Therefore, you will probably also need a larger hot water tank to meet your needs.

What should be considered when converting to an air heat pump?

Most households need some adjustments to work with a heat pump. They're great at keeping your home warm, but you may need to take some steps to keep that heat from escaping in order to get the best running costs.

Advantages of the air source heat pump

  • Highly efficient in generating heat and hot water

  • Zero CO2 when used with a renewable tariff

  • Can approach running costs of other home heating systems

  • You may be eligible for a £5,000 rebate with theKessel-Upgrade-Schema

  • They are easier to install than groundwater pumps that require digging in your yard

  • Low-maintenance with a long service life

  • Some systems can provide cooling in summer

Disadvantages of the air source heat pump

  • Your radiators feel warm, not hot

  • Best for retaining ambient heat but not for boosting warmth

  • Keep the heat in – consider upgrading your insulation to keep running costs low

  • The installation can take between 3 and 8 days

  • You need space – outside for the pump, because the air needs to circulate, and inside for the water reservoir

(Video) A guide to air source heat pumps - E.ON

Are there different types of air source heat pumps?

Yes! There are two main types of air source heat pumps, "air to air" and "air to water". Most air source heat pump installations in the UK are of the so-called 'air to water' type.

Air Source Heat Pumps: A Complete Guide (4)

"Air to water" air heat pumps

Most air source heat pump installations in the UK are so-called"Air Water"types. With these systems, the heat is transferred to a conventional “wet” heating system. And this facility gives you hot water and central heating.

"Air to air" air heat pumps

A minority of UK air source heat pumps are "air to air’. And, as the name suggests, these give off the heat to the room air that is distributed in the house. However, they do not provide hot water. They can be switched between heating and cooling depending on the season, better known as air conditioners.

(Video) Introduction to Air Source Heat Pumps

There is also a hybrid air source heat pump, which can often be combined with an existing central heating system and boiler. With these air source heat pump hybrid systems, the heat pump supplies a "base load" for daily heating and hot water preparation. The boiler only heats up to provide hotter water. Or a quick burst of warmth during a particularly cold snap.

What is the cost of installing an air source heat pump?

An air source heat pump costs more than a new gas or oil central heating system. Typical costs range from £12,000 to £17,000 depending on pump brand and heat output.

You also need to pay the installation cost. If you are installing a new underfloor heating or air distribution system, you must also take these costs into account. And possibly improved insulation, as air source heat pumps are not very effective at heating drafty or poorly insulated homes.

The government introduced the Boiler Upgrade Scheme (BUS) which provides£5,000 for air source heat pump installations. The scheme therefore puts the typical cost of an air source heat pump between £7,000 and £12,000.Find out if you qualify.

How high are the operating costs of an air source heat pump?

Air source heat pumps are among the most efficient devices on the market to heat your home. Conventional boilers run again with an efficiency of about 92%. This means that only 92% of the energy used by the boiler is converted into heat for your home. So you lose at least 8% of the energy to the process of burning fossil fuels to provide the heat. Older boilers can even be around 70% efficient and lose 30% energy. Heat pumps, on the other hand, have an efficiency of over 300% - for every 1 kW of electricity consumed, 3 kW of thermal energy are generated. When weighing the environmental benefits against the fossil fuel options, heat pumps are a better choice.

Example of running costs for an air source heat pump in a four bedroom house

Energy prices vary - and our homes and energy use are different too. So it's difficult to give an exact number of how much money it might cost. But, based on fuel cost numbersEnergy Confidence, we put this example together.

A four bedroom house may need around 18,000 kWh of heat per year (although this can vary). We divide the heat demand by the unit's efficiency and then multiply it by the fuel price to get the total running cost. Therefore, to heat this particular home at current average fuel prices:

  1. A new gas boiler could cost around £2,015 a year:(18.000 kWh÷ 92 %) x 10,3 Pence pro kWh Gas
  2. An older, 70% efficient gas boiler could cost around £2,648 a year:(18.000 kWh÷ 70 %) x 10,3 Pence pro kWh Gas
  3. An oil fired boiler could cost around £1,800 a year:(18.000 kWh÷ 92 %) x 9,2 Pence pro kWh Beer
  4. A boiler running on LPG would cost around £2,367 per year:(18.000 kWh÷ 92 %) x 12,1 Pence pro kWh LPG
  5. An air source heat pump would cost around £1,888 per year:(18.000 kWh÷ 324 %) x 34 pro kWh Strom

Are there maintenance costs for air source heat pumps?

Air Source Heat Pumps: A Complete Guide (5)

Air source heat pumps use proven technology and can aworking life of 20 yearsor more. But just like a boiler, you should have your air source heat pump professionally serviced - every two or three years (or annually if that's the manufacturer's recommendation) - to ensure it's still performing at its best. There are some things you can do yourself:

  • Make sure there is sufficient air supply. That means regularly checking for leaves or debris caught in the fan grills. And cut back any plants that are growing too close to the unit or its pipes.
  • In very cold weather, clear the air source heat pump of snow and check that the grilles are not blocked by ice.
  • Run the heat pump to the installer's recommendations, which may take some getting used to - but heat pumps run best when left alone.
(Video) What Are the Running Costs Of AIR SOURCE HEAT PUMPS? | GreenMatch

How to get an air source heat pump

Air source heat pumps are best suited to well-insulated homes and ideally work in tandem with technologies such as underfloor heating. Your home must also have outdoor space.

Find out how to get an air source heat pump

Related Articles

Ultimate Guide to Energy Performance Certificate EPC Assessments

19. Oct. 2020

Learn more

Gas boiler ban in the UK - everything you need to know

19. Oct. 2020

Learn more

Heating oil prices: why pay more?

19. Oct. 2020

Learn more

(Video) Air source heat pump/Electric heating, starting the calculations


What is the most reliable air source heat pump? ›

What are the best air source heat pump brands?
  • Best overall: Samsung EHS Monobloc.
  • Most efficient: Hitachi Yutaki.
  • Most powerful: Vaillant flexoTHERM 400V + aroCOLLECT.
  • Best for cold climates: Daikin Altherma.
  • Best for small homes: Nibe F2040.
  • Best for combining other sources: Calorex.
  • Best for scalability: Danfoss.
Jan 4, 2023

What are the disadvantages of air source heat pumps? ›

Disadvantages of Air Source Heat Pumps
  • Lower Heat Supply than Boilers. ...
  • Extra Spending to Install Underfloor Heating. ...
  • Your Home Must Be Well-Insulated Already. ...
  • Lower Efficiency Below 0°C. ...
  • Lower Savings Compared to Low Price Mains Gas. ...
  • ASHPs Can Be Noisy.

At what temperature do air source heat pumps stop working? ›

The Minimum Temperature Requirements for Heat Pumps

For the brands and models that are towards the higher end, you can expect the efficiency to stop at around -18 to -22 degrees Celsius. You may even be lucky enough to find models that will remain efficient up to -25 degrees Celsius.

How big of a heat pump do I need for a 1500 square foot house? ›

The Rule of Thumb for a Heat Pump Properly Sized for Your Home. While all these factors are used by contractors to determine the exact size heat pump you need, there is a general rule of thumb you can follow. For every 500-600 square feet of conditioned floor area, install one ton of air conditioning capacity.

What is the best cold weather air source heat pump? ›

Based on our research, the best cold climate heat pump is Mitsubishi's Hyper-Heating, or H2i. Listed as Mitsubishi's M-Series or P-Series for home installation, these heat pumps maintain their full heating capacity down to 5F, and can produce useful heat down to -13F.

Why is my electric bill so high with air source heat pump? ›

Improper maintenance of your heat pump could lead to a 25 per cent increase in your energy bills. Blocked and dirty filters reduce the amount of airflow that can pass through the system and may harm performance. It's also worth checking the fan regularly to ensure there isn't any debris, such as leaves, stuck in it.

Do air source heat pumps work in very cold weather? ›

Yes! It's equally possible to enjoy all the benefits of an air source heat pump in cold weather as it is through the milder months. Air source heat pumps can easily withstand up to at least -10°C, with some being durable enough to work at temperatures as low as -25°C.

How noisy is an air source heat pump? ›

Are heat pumps noisy? Answer: All heating products make some noise, but heat pumps are usually quieter than fossil fuel boilers. A ground source heat pump may reach 42 decibels, and an air source heat pump may reach 40 to 60 decibels, but this depends on manufacturer and installation.

Will a heat pump work at 25 degrees? ›

For this reason, heat pumps start to lose efficiency at around 40 degrees F and become less efficient than furnaces at around 25 degrees F. Heat pumps continue to be effective at cooling the indoors, even at high temperatures. In the South, it rarely gets below 25 degrees.

Do heat pumps work below 30 degrees? ›

Most standard heat pumps will function at 100% efficiency until the outside temperature reaches about 40° F. However, when the temperature dips below this, most heat pumps are not able to maintain efficiency. They become much less effective at temperatures between 20° F to 30° F.

Should I turn my heat pump off in extreme cold? ›

Rebate-eligible heat pumps can reach over 400% efficiency in mild temperatures and can maintain well over 200% efficiency even into negative temperatures. This is why turning off a heat pump in frigid temperatures and opting to use a fossil fuel boiler or furnace instead is a mistake.

Is it better to oversize or undersize a heat pump? ›

If a heat pump is undersized for a room, the negative effects can become quite obvious, fast. It's simply not going to adequately heat or cool the room it's in, and it will certainly work harder than it should in order to do so. Naturally, this can lead to a host of mechanical problems over time.

Is it OK to oversize a heat pump? ›

An oversized HVAC unit can make your home's inside temperature uncomfortable. An HVAC system with excess capacity can heat or cool your home faster, but that speed often results in a couple of other issues. First, your home won't benefit from gradual, even heating and cooling.

What happens if heat pump is too big? ›

If your heat pump is too large for your home, it will short (or rapid) cycle, which isn't healthy for the motor. If too small, it will constantly try to run to meet your temperature needs. Not only are both issues annoying, but it can cost you.

What size heat pump do I need for 2000 sq ft home? ›

If you Google “heat pump calculator,” you'll probably find a rule of thumb like this: “You need 30 BTUs of heat for every square foot of living space you want to heat or cool.” If you have a 2,000-square-foot home, this rule of thumb suggests you need a 60,000 BTU heat pump.

What is better than a heat pump? ›

While there are a number of variables that greatly influence the life expectancy of a HVAC system, central AC units typically last longer than Heat Pumps. The reason is that heat pumps heat and cool a home, so they are used year-round.

What is the quietest heat pump on the market? ›

Quietest Heat Pump - Trane XV19 low profile

The Trane XV19 low profile heat pump checks in with sound levels starting as low as 43 dBA — making it the quietest system in our lineup.

Do heat pumps work below 20 degrees? ›

Do heat pumps work below 20 degrees? Yes, air source heat pumps work below 20 degrees Fahrenheit—in fact, they can perform well below -10!

Why are heat pumps not used in northern states? ›

Since they work by absorbing free heat from the air outside your home, then transferring it inside, their job gets tougher when it's chilly out. They'll struggle to keep your house comfortable even in a mild cold snap, the story goes, and they won't run efficiently in that kind of weather, anyway.

Do mini splits work below 20 degrees? ›

Mid-level mini splits run at 100 percent efficiency down to 20°F and typically require a base pan heater. These work well for heating moderate to cold climates. Economy-level mini splits run at 100 percent efficiency down to 30°F and may shut off at temperatures below 20°F. These are best for moderate to warm climates.

Should I leave my air source heat pump on all the time? ›

When you don't want heat. Heat pumps should NEVER be turned off completely. This is because they will be extremely expensive when turned back on as they will try to raise the temperature as quickly as possible. It can also take several days to restore the home to a comfortable temperature. .

Is it cheaper to leave heat pump on all day? ›

While heat pumps are the most cost effective way to use electricity to heat your home during the cooler months, leaving them running day and night is not economically efficient. According to Energywise, you should switch off your heat pump when you don't need it. This is to avoid excessive energy waste.

Where is the best place to site an air source heat pump? ›

Almost always, we would recommend positioning the unit on the floor immediately outside your house or property. This has two large benefits: first, it reduces the amount of pipework you need in order for your air source heat pump to fully cater to your property, avoiding increased unnecessary heat loss.

Is it OK for a heat pump to run all night? ›

If you're more familiar with a large furnace cycling off and on for most of the Indiana winter, then a heat pump running constantly, 24/7 makes you suspicious that something is wrong. Do not worry. This is exactly what the heat pump is designed to do. Heat pumps are very energy efficient.

Do heat pumps use a lot of electricity? ›

One of the most popular questions we hear is, “do heat pumps use a lot of electricity?” We are delighted to answer that they do not. Compared to more traditional methods of heating, ductless heat pumps are much more energy-efficient, which means they have less impact on your utility bills.

Can a heat pump heat a whole house? ›

A whole-house heat pump can provide heating and cooling for your entire home, making it a great choice for those who want an energy-efficient solution.

Who makes the quietest air source heat pump? ›

Heat pumps are a popular alternative to boilers as a way to heat homes but can also be distractingly noisy – except these ones, of course. Quiet Mark Accredited heat pumps include the Grant Aerona³ R32 Air Source, also noted for its efficiency, the Warmflow Zeno and the Vaillant aroTHERM Plus.

How far from house can air source heat pump be? ›

All parts of the air source heat pump must be at least one metre from the property boundary. Installations on pitched roofs are not permitted development. If installed on a flat roof all parts of the air source heat pump must be at least one metre from the external edge of that roof.

Are air source heat pumps noisy for Neighbours? ›

The air can produce noise when passing through the heat exchanger, with a variable intensity depending on the pressure. This causes buzzing sounds to be emitted and it's this constant hum that proves to be the most disturbing to homeowners and neighbours.

Is 72 a good temperature for heat in the winter? ›

The ideal thermostat temperature in the winter is 68 degrees Fahrenheit when you're at home. suggests that 68 degrees is a good room temperature while you're awake at home but recommends lowering it while you're asleep or away.

How much frost is OK on a heat pump? ›

As a general rule of thumb, if frost stays on the coil for two hours or more, then something is wrong. It's time to call your Maryland HVAC Repairman to diagnose the problem.

How can I make my heat pump more efficient in the winter? ›

KEEP IT LOW. Don't set your heat pump to the maximum temperature as it won't heat the room any quicker, but it will use more energy. The best way to use a heat pump is to keep the setting low (18°C to 21°C). DON'T RUN IT ALL DAY.

What is cheaper to run heat pump or gas furnace? ›

What is cheaper to run—heat pump or gas furnace? Heat pumps are often cheaper to run than gas furnaces, but this often depends on energy costs in your state. Overall, heat pumps are up to 3x more efficient than traditional heating, like gas furnaces, so they do use less energy to produce the same amount of heat (7).

Can a heat pump warm a house in winter? ›

In the winter, heat pumps absorb heat from the outside air and use it to warm your home. They use a relatively small amount of electricity to run, making them less expensive to operate than a natural gas furnace.

Which heat pumps last the longest? ›

A dual-source pump usually lasts the longest out of all three kinds. Heat pumps are more efficient than air conditioners because they both heat and cool your home; there is no need to install a heating and a cooling system.

Is the major problem of air source heat pump system? ›

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.

What is the best COP for air source heat pump? ›

The efficiency of an air source heat pump is measured by the Coefficient of Performance (COP). This refers to the maximum efficiency with which the heat pump can run. Most air source heat pumps have a COP between 2 to 4, but in some cases, it can be as high as 5.

What is the best time of year to buy a heat pump? ›

For many people the decision to invest in a heat pump takes place around the end of summer. September is the peak sales period for heat pumps and most heat pump sales occur between August and December in many countries (southern countries being an exception).

What is the major problem of heat pump? ›

A clogged air filter is a common cause behind a heat pump not working, as the system doesn't receive adequate airflow due to this obstruction. The system often overheats and shuts down, leaving you without cooling. Or, not enough cooling makes it into your home due to the restriction.

How many square feet will a 3 ton heat pump cool? ›

While 3-ton heat pumps are not necessarily heavier than smaller-capacity pumps, they will likely cost more to buy and install. A quality 3-ton heat pump can effectively heat or cool an average area of 1,500 square feet but will be too large for smaller spaces.

How many square feet does a 6 ton heat pump cover? ›

3,000 square feet: 6 tons.


1. How I fitted an Air Source Heat Pump ASHP: Samsung Gen6 5kW
(Glyn Hudson)
2. Air-Source Heat Pump - How it works
3. The Ultimate Guide to Heat Pumps
(Nu-Heat Underfloor Heating & Renewables)
4. What is an air source heat pump?
(Energy Saving Trust)
5. Introduction to Air Source Heat Pumps
(Nu-Heat Underfloor Heating & Renewables)
6. This is Why Heat Pumps May NOT Be The Future
(Skill Builder)


Top Articles
Latest Posts
Article information

Author: Mrs. Angelic Larkin

Last Updated: 18/10/2023

Views: 6208

Rating: 4.7 / 5 (67 voted)

Reviews: 82% of readers found this page helpful

Author information

Name: Mrs. Angelic Larkin

Birthday: 1992-06-28

Address: Apt. 413 8275 Mueller Overpass, South Magnolia, IA 99527-6023

Phone: +6824704719725

Job: District Real-Estate Facilitator

Hobby: Letterboxing, Vacation, Poi, Homebrewing, Mountain biking, Slacklining, Cabaret

Introduction: My name is Mrs. Angelic Larkin, I am a cute, charming, funny, determined, inexpensive, joyous, cheerful person who loves writing and wants to share my knowledge and understanding with you.