Project looks at R290 heat pumps in apartments

A German research company is planning the development of propane heat pumps to replace gas and oil heating systems in existing apartment buildings.

Engineers at the Fraunhofer Institute for Solar Energy Systems ISE, which recently achieved outputs of 7-10kW with less than 150g of propane refrigerant, are now working on developing easy-to-use and replicable solutions for existing apartment buildings.

Under the new project, LC R290 – Low charge HP solutions, the Fraunhofer ISE will initially focus on floor heating systems in a project consortium with companies from the heating industry and the housing industry.

Ultimately, Fraunhofer ISE wants to develop heat pump solutions for three fields of application: floor heating systems, central heating systems installed indoors and higher performance classes for heat pumps installed outdoors.

“We need standardised heat pump solutions for replacing gas and oil heating systems for all applications in the housing industry. Propane has become an accepted refrigerant solution for the heat pump industry and is now widely used in outdoor heat pumps. What we now need are solutions that can also be implemented indoors,” explained Dr Ing Lena Schnabel, head of the heat and cooling technology department at Fraunhofer ISE.

The new joint project with its budget of €7m funded by Germany’s Federal Ministry of Economics and Climate Protection, is intended to close these gaps. The planned duration is until June 30, 2025.

If heat pumps are to be operated with propane as a replacement for gas floor heating or gas and oil heating in the basement, special safety requirements must be observed for filling quantities of more than 150g. In its earlier LC150 project, the Fraunhofer ISE project team demonstrated that a heat output of 7-10kW can be achieved with less than 150g of propane refrigerant. This will be the basis for implementation as a floor heating system. Cooling Post