GERMANY: A German research institute claims to have developed a prototype hydrocarbon domestic heat pump with a heat output of 8kW from just 150g of propane.
According to developers at Fraunhofer ISE, this means that the newly developed prototype could be installed inside the building without implementing additional safety requirements.
Currently, a typical 5kW-10kW heat pump in a single-family home would exceed the 150g upper limit for hydrocarbons.
The new brine-to-water prototype is said to require only 25% of the refrigerant compared to conventional heat pumps of the same power.
“The objective of our work is to develop a heat pump that uses a climate-friendly refrigerant and at the same time achieves high power and efficiency using the lowest possible refrigerant amount,” commented Dr Lena Schnabel, department head of heating and cooling technology at Fraunhofer ISE.
Now the researchers in Schnabel’s department want to optimise the system and attract industry partners for a wide implementation of the technology on the German and European market. Increasing the efficiency and developing a design for series production are a priority.
Key to the prototype is the low-charge requirement of the asymmetrical plate heat exchanger design. Researchers says they could also greatly reduce the refrigerant demand by decreasing the amount of oil in the compressor.
Fraunhofer ISE performs research on heat pumps along the entire value chain: from materials, through component and device development up to quality assurance and monitoring in the field. The institute also has an accredited test lab for heat pumps and chillers.