RESEARCHERS from Glasgow University have developed a new type of heat pump which could help households save on energy bills and contribute towards net-zero goals.

Heat pumps are a low-carbon alternative to gas boilers. They draw energy from external low-temperature sources, most commonly outdoor air, in order to heat indoor spaces. When powered by renewable sources of power, they are significantly more environmentally friendly than conventional gas boilers.

The UK Government has set a target for 600,000 heat pump installations per year by 2028 in order to reduce the country’s carbon footprint.

However, the heating capacity and energy efficiency of the current generation of heat pumps can be impacted by cold weather, particularly for air source heat pumps. High capital and operational costs and relatively low heat supply temperature have limited the growth of their take-up in the UK.

In a paper published in the journal Communications Engineering, the researchers outline how their flexible heat pump technology provides an elegant and low-cost solution to the problems of current heat pumps by integrating heat storage – a small water tank and a coil of copper tube.

The water tank recovers some excess thermal energy produced during the pump’s operation, and stores it as an additional heat source for the heat pump’s operation later.

The recovered heat has a much higher temperature than the outdoor air that provides the heat source, and it can be reused as a temporary heat source, substantially reducing the pump’s power consumption.

The researchers have demonstrated the advantages of their new heat pump by building a working prototype using off-the-shelf components. Thorough testing against current-generation heat pump designs has shown their design to be around 3.7% more efficient than current designs.

The team have protected their invention with a PCT patent, and are actively looking for ways to make the flexible heat pump technology commercially available in the near future.

Zhibin Yu, professor of thermal energy at Glasgow’s University’s James Watt School of Engineering, led the research and development of the flexible heat pump.

He said: “We’re at a critical juncture in our global move towards net zero, where we need to start scaling up our low-carbon infrastructure quickly and effectively. That urgency is being particularly keenly felt at the moment, where many households are facing rapidly escalating bills.

“Our flexible heat pump solves many of the problems with the current generation of heat pumps.

“The cost of a small water tank heat storage is marginal, but the power saving is significant.”