Thermoacoustic heat pumps which utilise sound waves to generate heat could be used to generate heat into our homes in the near future.
The new technology utilises existing heat pump methods but instead of using potentially dangerous liquids thermoacoustic pumps use helium which is not only safer, but better for the environment.
This latest advancement has the potential to revolutionise heat pump technology and replace ground and air source heat pumps as the greenest and most efficient heating system. Here, we take a look at how the technology is developing and when and if it might be rolled out to use in our homes.
How do thermoacoustic heat pumps work?
Thermoacoustic pumps use a totally different approach to generate heat and cold from traditional heat pumps.
Heat pumps are the most sustainable heating and cooling devices. They extract heat from a source, such as the air or the ground, and release it into the house before recycling it again.
Heat pumps commonly employ the vapour-compression cycle as the prevailing method for heat transfer. This cycle relies on the evaporation and condensation of a refrigerant (liquid) to transport energy and elevate temperatures.
In this process, the condensation point of the refrigerant is fixed. This method is efficient if the desired temperatures are near the condensation point, but if it isn't, the efficiency decreases.
On the other hand, thermoacoustics use helium rather than refrigerants, a gas that isn't reliant on heat to work. An acoustic wave emitted by hi-fi speakers is used to compress or expand helium contained within a vessel at a pressure of 30 bars, which heats or cools down the water in the pump core.
Therefore, in theory, thermoacoustic pumps can operate across a wide range of temperatures and potentially work all year round with no drop-off in efficiency.
Thermoacoustic heat pumps are surprisingly silent
For a heat pump that generates heat by using sound waves, it is actually surprisingly quiet. When in use, the thermoacoustic heat pump operates at less than 30dB, which is about the same as a modern fridge, explains BlueHeart Energy, one of the leading companies creating the heat pump.
This is because the technology includes a noise cancelling system. But this doesn't mean the heat pump is large either, with its overall size coming in at a compact 55cm all around cube shape, far small than our existing heat pumps due to the reduction of its domestic hot water auxiliary tank.
With a 1-6kW modulating output
The thermoacoustic heat pump has emphasis on making sure it has a lower energy consumption, operating with an impressive 1-6kW modulating output (output at varying rates).
It is also claimed to be easy to install with a standardised system that can adjust to any type of building. The heat pump's simple architecture with no moving parts means that it has a lifetime of more than 15 years and, according to BlueHeart, no need for maintenance.
As previously mentioned, the thermoacoustic heat pump is also claimed to be 100% clean as it uses helium, an inert gas, rather than refrigerants - putting it on track to be compliant with 2050 environmental targets. The helium is also super safe as it isn't flammable.
When will thermoacoustic heat pumps be available?
Prototypes of these heat pumps are currently being created with BlueHeart claiming their product will be ready by end of 2024. However, these will have to be tested by an initial sample of customers. If this is successful, the thermoacoustic heat pump should be commercially available sometime in 2025.
However, according to Philippe Loyer, Product Manager at Equium, a rival thermoacoustic heat pump manufacturer, they expect to "go to market in 2024”.
If you are wondering if this affects whether you should swap your gas boiler for a heat pump now or wait for this technology then you need not worry as the thermoacoustic core component can be installed into all heat pumps to provide cleaner, safer and more efficient heat pumps, which means customers will not have to buy completely new heat pumps.
