What is an R290 Air-to-Air Heat Pump? The Eco-Friendly Air Conditioning Upgrade
Key Takeaways
- R290 air-to-air heat pumps can heat and cool your home.
- R290 has a GWP of three, which is much lower than R32 and R410A.
- R290 is not an F-gas, but it is highly flammable.
- The type of refrigerant is not the only factor that affects a heat pump’s efficiency.
- Proper sizing, system design, and professional installation are all important for safe and reliable performance.
Air conditioning is now about more than just getting through the hottest weeks of summer.
The UK’s climate is getting noticeably warmer.
According to the Met Office, 2025 was the warmest year recorded in the UK since the national temperature series began in 1884. The decade from 2016 to 2025 was also 1.33°C warmer than the 1961–1990 average.
With hotter summers and more extreme heat, homeowners may need better ways to manage indoor temperatures all year round.
Modern air-to-air heat pumps can cool your home when temperatures rise and provide efficient heating when the weather turns colder. Now, some systems are taking another step forward by using R290 refrigerant.
But what exactly is R290, and why is it attracting so much attention?
What Is R290 Refrigerant?
A refrigerant is a substance inside an air-conditioning or heat pump system that carries heat from one place to another.
To work well, it needs to absorb heat, release it when needed, and switch between liquid and gas at the right temperatures and pressures.
It also has to stay stable as it cycles through the system again and again.
Other important things to consider are:
- Energy efficiency
- Environmental impact
- Operating pressure
- Safety
There are numerous types of refrigerants. Some may be flammable, toxic or capable of contributing to global warming.
Manufacturers must therefore carefully match each refrigerant to the system’s design and intended use.
The UK Government publishes guidance covering fluorinated greenhouse gases, professional qualifications and environmental responsibilities.
In England, the Environment Agency enforces relevant F-gas requirements. These rules apply to fluorinated refrigerants such as R32 and R410A rather than R290.
R290 is the technical name for a highly purified form of propane used as a refrigerant in some modern air-conditioning and heat pump systems.
It transfers heat efficiently and has a much lower potential climate impact than many conventional refrigerants.
However, R290 is highly flammable. Equipment must therefore be specifically designed to use it, while trained professionals should carry out installation and servicing.
R290 remains an emerging option in parts of the domestic air-to-air market. Homeowners should therefore check product availability and installation requirements carefully.
How Does an R290 Air-to-Air Heat Pump Work?
An R290 air-to-air heat pump uses electricity and a refrigeration cycle to move heat between the inside and outside of your home.
During colder weather, the outdoor unit absorbs heat from the outside air. The refrigerant carries that heat through the system before an indoor unit releases it into the room.
When cooling is required, the process works in reverse. The system absorbs excess heat from inside your home and transfers it outdoors.
This means a reversible air-to-air heat pump can provide both heating and air conditioning from the same system.
Unlike an air-to-water heat pump, it does not usually deliver heat to radiators or an underfloor heating system.
Instead, indoor units distribute warm or cool air directly into individual rooms.
A standard air-to-air heat pump usually doesn’t provide hot water, so you’ll still need a separate water heater for showers, baths, and taps.
How Does R290 Compare With R32 and R410A?
To see why R290 is getting noticed in the UK, it helps to compare it with two common refrigerants: R32 and R410A.
Refrigerants are often compared using their Global Warming Potential, or GWP.
Jargon Buster: Global Warming Potential (GWP)
A metric used to estimate how much heat a greenhouse gas traps in the atmosphere over a set period (usually 100 years) compared to an equal mass of carbon dioxide.
GWP estimates how much warming a greenhouse gas could cause compared with the same amount of carbon dioxide over a set period, usually 100 years.
Carbon dioxide has a GWP of one. So, the higher a refrigerant’s GWP, the bigger its potential impact on the climate if it leaks.
| Refrigerant | What is it? | GWP rating | Safety classification |
|---|---|---|---|
| R290 | Refrigerant-grade propane | 3 | A3: higher flammability |
| R32 | A fluorinated HFC refrigerant | 675 | A2L: lower flammability |
| R410A | A blend of two fluorinated HFC refrigerants | 2,088 | A1: no flame propagation under standard test conditions |
R32’s GWP is much lower than R410A’s, which is why it’s now used more often in new air conditioners.
But R32’s GWP is still 675, which is much higher than R290’s GWP of three.
UK Government research describes R32 as a lower-GWP replacement for R410A in smaller air-conditioning systems.
R410A has a GWP of 2,088. Although it remains present in many existing systems, its relatively high potential climate impact has encouraged manufacturers to move towards lower-GWP alternatives.
When comparing equal amounts of refrigerant, R32 has approximately 225 times the GWP of R290, while R410A has around 696 times the GWP.
These figures compare the refrigerants themselves rather than the total lifetime emissions of complete systems.
Does a Lower GWP Automatically Mean a Better System?
Not necessarily.
A refrigerant’s GWP measures its potential effect if it escapes into the atmosphere.
It doesn’t tell you how efficiently your air conditioner will run, how much electricity it will use, or if it’s right for your home.
The overall performance of an air-to-air heat pump also depends on:
- The design and efficiency of the equipment
- The amount of refrigerant inside the system
- Correct system sizing
- Installation quality
- Insulation and heat loss within the property
- How frequently is the system used
An Engineer’s View
Transitioning to R290 refrigerant represents a massive leap forward in making our home cooling and heating greener, thanks to its exceptionally low Global Warming Potential. However, its high flammability means you must rely on fully qualified professionals to ensure the system is properly sized, installed, and compliant with safety regulations.
– Rhys Powell, Engineer
R290 offers a clear advantage when comparing refrigerant GWP ratings.
However, it still requires equipment designed specifically for R290 and careful installation by appropriately trained professionals.
Homeowners should never attempt to replace one refrigerant with another.
Refrigerants aren’t interchangeable. Each system is built to work with a specific refrigerant, pressure, and safety features.
What Are the Benefits of an R290 Air-to-Air Heat Pump?
An R290 air-to-air heat pump brings several practical and environmental benefits.
Heating and Cooling From One System
One big advantage is being able to control your home’s temperature all year.
The system heats your home when it’s cold and cools it when it gets warm inside.
This can be especially helpful in homes that get too hot during the summer.
A Very Low-GWP Refrigerant
R290 has a significantly lower GWP than commonly used refrigerants such as R32 and R410A.
If any refrigerant leaks out, R290 has a much smaller warming effect than R32 or R410A.
Efficient Heat Transfer
Air-to-air heat pumps transfer existing heat rather than generating heat directly through electrical resistance.
However, actual efficiency will depend on the system, outdoor conditions, room temperatures, property heat loss and installation quality.
Individual Room Control
Multi-split systems can connect several indoor units to one outdoor unit.
Depending on the equipment and controls, this may allow homeowners to manage temperatures in different rooms separately.
Rather than heating or cooling the entire property unnecessarily, you can focus temperature control on the spaces being used.
Is an R290 Air-to-Air Heat Pump Suitable for Your Home?
Suitability depends on more than the refrigerant inside the equipment.
An installer should assess:
- The rooms you want to heat and cool
- The property’s insulation and heat loss
- The number and position of indoor units
- Available space for the outdoor unit
- Pipework and condensate drainage routes
- Expected noise levels
- Your existing heating and hot-water system
- How often you plan to use the heating and cooling functions
Air-to-air heat pumps may be particularly useful in smaller homes, flats, extensions, converted lofts, home offices and rooms that regularly overheat.
They may also suit homeowners who want room-by-room temperature control but do not need the system to provide domestic hot water.
Recent UK Government modelling examined how reversible air-to-air heat pumps could perform across different UK homes, including their heating and cooling performance, energy use and running costs.
The findings show that outcomes vary according to the property, system configuration and usage pattern.
A professional assessment can then establish whether a particular air-to-air system, including an R290 model, is suitable for the home.
Should You Choose an R290 Air-to-Air Heat Pump?
R290 air-to-air heat pumps combine year-round heating and cooling with a refrigerant that has a much lower Global Warming Potential than R32 or R410A.
However, refrigerant choice is only one part of the decision.
The right system must also suit your property, comfort requirements, room layout and existing hot-water arrangements.
Correct system sizing and professional installation will ultimately have a greater effect on everyday comfort than the refrigerant name printed on the technical label.
Let WarmZilla Help With the Selection Process
WarmZilla can help take the guesswork out of choosing a home climate control system.
Our role is to help you find a home climate control system that suits your property, comfort needs, and budget.
That includes looking at the type of system, the size of the space, the installation requirements and the technology inside the unit.
Frequently Asked Questions
Is R290 The Same Propane Used For Barbecues?
R290 is propane, but air-conditioning systems use refrigerant-grade propane manufactured to a high level of purity.
It circulates inside a sealed refrigeration system and is not used as a fuel by the heat pump.
Is R290 An F-gas?
No. R290 is a hydrocarbon refrigerant and does not contain fluorine.
It is therefore not classed as a fluorinated greenhouse gas and is not subject to the same F-gas phase-down rules as refrigerants such as R32 and R410A.
Its flammability still means that appropriate safety rules, product standards and manufacturer requirements apply.
Can An R290 Heat Pump Provide Both Heating And Cooling?
Yes. A reversible R290 air-to-air heat pump can transfer heat into the home during colder weather and remove heat during warmer conditions.
The same indoor unit can therefore provide warm or cool air, depending on the operating mode.
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