Air source heat pumps: What are they & how do they work?
Over the past few years, air source heat pumps have become increasingly common in UK homes, hailed as a sustainable alternative to traditional heating solutions.
But what are the tangible benefits of these high-tech appliances? How do they work? And can they really replace your trusty boiler?
In this guide, learn everything you need to know about air source heat pumps, including advantages, average running costs and lifespan, to help you decide whether this heating solution is suitable for your home.
What is an air source heat pump?
An air source heat pump (ASHP) is a renewable heating system that extracts heat from the outside air and transfers it into your home. An ASHP absorbs warmth from the air, even in cold temperatures, and uses it to heat water for your central heating system.
Learn the differences between heat pumps and gas boilers.
Air source heat pumps also shouldn’t be confused with other heat pump types, such as ground-source and water-source heat pumps. Our guide to different types of heat pumps can explain the differences between these appliances further, allowing you to make the best decision for your home.
How does an air source heat pump work?
Air source heat pumps operate on the principles of thermodynamics. This is the science behind how heat, temperature and energy transfer from one place to another.
They consist of an evaporator, compressor, condenser, and expansion valve that work in a continuous loop.
Air is drawn in by the fan from outside and passes over the refrigerant fluid.
The refrigerant captures heat from the air and becomes warm vapour.
The vapour then passes through a compressor, producing hot refrigerant and usable heat.
Heat from the hot refrigerant is then transferred to the heating and hot water cylinder through a heat exchanger.
Once the heat has been transferred to the house, the refrigerant passes through an expansion valve, which reduces its temperature, making it cold again and enabling it to absorb heat from the air, continuing the cycle.
What temperature does an air source heat pump produce?
The temperature produced by an air-source heat pump can vary depending on the pump. Traditional heat pumps can operate at up to 55℃, although they run most efficiently at 35-45℃.
However, units using the newer R290 refrigerant, such as our own HP290 heat pump, can reach higher temperatures, around 70℃. This is great for older, less insulated homes. We have a dedicated guide to the HP290 heat pump so you can decide if this is the right heating option for you.
How does an air source heat pump work in winter?
We know what you’re thinking. If a heat pump draws its warmth from the air, surely that would make it ineffective during winter? Yet, due to the nature of ASHP technology, this isn't the case.
Contrary to common misconceptions, ASHPs can operate efficiently in winter conditions. Modern systems are designed to extract heat even from cold air, ensuring a reliable heat source for your home throughout the colder months.
This is possible because the refrigerant flowing around the heat pump’s system can absorb heat from the air even in temperatures lower than -20°C.
Learn how heat pumps work in winter.
What are the advantages and disadvantages of air source heat pumps?
Before you can decide whether to invest in an air heat pump for your home, you should understand the benefits and drawbacks.
Advantages of Air Source Heat Pumps
Energy efficiency:
ASHPs are highly efficient and provide significantly more heat output than the electricity they consume. Some models offer up to 3-4 units of heat for every unit of electricity (300-400% efficiency). This is much higher than fossil fuel heating systems like conventional boilers, which can offer anything from 0.7-0.9 units of heat per unit of fuel (70-90% efficiency).
Sustainable heating:
They harness heat from the air, a renewable resource, and can be powered by electricity generated from renewable sources. ASHPs also contribute to reducing carbon emissions compared to traditional, fossil-fuel-powered heating systems. This is especially true for heat pumps using R290 refrigerant, which has an incredibly low Global Warming Potential and an Ozone Depletion Potential of 0.
Disadvantages of Air Source Heat Pumps
Initial cost:
The upfront cost of purchasing and installing an ASHP can be higher than that of traditional systems. However, grants and schemes are available to reduce these costs, as we’ll discuss further down.
Space requirements:
ASHPs require a small amount of space outdoors, which can sometimes rule them out for properties like apartments. Sufficient space is also needed for a hot water cylinder; the space needed can vary depending on the size of the property. However, air source heat pumps require far less space than ground source or water source models.
A quick side-by-side comparison shows that ASHPs provide an eco-friendly alternative to conventional heating systems.
Learn more about the benefits of upgrading to a heat pump.
How much does an air source heat pump cost?
The cost of an ASHP installation can vary significantly based on various factors, such as the type of system, your property's size, and existing heating infrastructure. On average, installations may range anywhere from £3,000 to £18,000.
Learn more about heat pump costs.
Can I get a heat pump through the Government’s Boiler Upgrade Scheme?
The UK Government's Boiler Upgrade Scheme offers financial incentives for homeowners to upgrade to energy-efficient heating systems. Air source heat pumps are eligible for this scheme, providing a cost-effective way to make your home more sustainable.
If eligible for the scheme, you could be granted the following financial benefits:
£7,500 towards an air source heat pump
£7,500 towards a ground source heat pump (including water source heat pumps and those on shared ground loops)
£7,500 towards a biomass boiler.
As it stands, the scheme allows for up to one grant per property. Want to know if you could be entitled to this financial aid? Check if you are eligible on the official GOV site or read Ideal Heating’s blog, which covers everything we know about the new Boiler Upgrade Scheme.
How much do air source heat pumps cost to run?
Running an air source heat pump can be very cost-effective, especially if you’re savvy about tariffs and deals available with energy companies. Cosy Octopus by Octopus Energy and EDF Energy both offer two periods of lower energy rates per day for heat pump users, while OVO Energy’s Heat Pump Plus allows you to pay 15p per kWh for the energy your heat pump uses.
How much electricity does an air source heat pump use?
The electricity consumption of ASHPs depends on several factors, including the system's size and efficiency, as well as the size of the home it has to heat. However, they typically use less electricity than traditional electric heating systems because they are at least 300% efficient, meaning the heat energy produced is more than 3x the electricity used. For this reason, heat pumps typically use about 10 kWh of electricity per day, although this increases for larger buildings.
How long does an air source heat pump last?
With proper maintenance and regular servicing, air source heat pumps can last up to 20 years or more.
Here are some key considerations that can influence their lifespan:
Quality of installation:
Proper installation by qualified professionals is crucial for the heat pump's performance. Poor installation can lead to inefficiencies. Learn about the benefits of heat pumps for installers.
Maintenance:
Regular maintenance, such as cleaning filters, checking refrigerant levels, and inspecting components, is essential to extending the heat pump's lifespan.
Brand and quality:
The quality of the heat pump itself, including the accompanying components used, can impact its durability. Higher-quality units may last longer and perform more effectively.
Learn what to expect from a heat pump service.
What size air source heat pump do I need?
Determining the right size for your air source heat pump is crucial for peak performance and efficiency. The size of your property, along with the heat demand, influences the system's size. For more information, get in touch with our experts.
Learn more about heat pump sizes.
Is a heat pump the right choice for my home?
The suitability of an air source heat pump depends on your home's specific requirements. Your home’s existing insulation, available space and installation costs all play a role. We have a guide to choosing the right heat pump for your home that can help you evaluate your options effectively.
Myth-busting air source heat pumps
There are several myths that surround air source heat pumps. The three main misconceptions are that:
They are ineffective during winter.
They are more expensive to run than traditional boilers.
They are very noisy.
In reality, and as outlined above, modern ASHPs are designed to tackle these challenges, providing reliable, cost-effective, and quiet heating solutions for homes.
Not only does its advanced technology allow the device to perform efficiently in cold temperatures, but it also lets you save money on your annual energy bills. Sound levels are also low to medium, between 40 and 60 dB.
Want to learn more about the myths surrounding heat pumps and the real facts that disprove them? Tune in to our Pump Fiction podcast.
Why Choose Ideal Heating for Your Air Source Heat Pump?
Ideal Heating is trusted by over 4 million UK households to heat their homes.
With our commitment to quality and sustainability and unique understanding of the British climate, we offer a range of air source heat pumps designed to meet the diverse needs of UK homeowners, providing dependable heat, snow or shine.
From professional installations to ongoing advice and support, Ideal Heating has everything you need to seamlessly transition to eco-friendly heating.
As technology advances and government incentives become more prevalent, now is an ideal time to explore the benefits of air-source heat pumps for your home.
If you want greener, more cost-effective heating, contact us today. Our helpful advisors will be happy to show you our range of air source heat pumps.
