30 August 2020

The EU-funded RES4BUILD project is developing integrated renewable energy-based solutions that are tailored to the needs and requirements of users and installers. The project aims to increase the uptake of renewable energy solutions for heating and cooling, decarbonising the energy consumption in buildings, and contributing to EU energy and climate goals. Low GWP HFO R-1234ze(E) has been selected for the multi-source vapour injection heat pump.

The consortium is working to improve the performance and reduce the cost of the most innovative components of the RES4BUILD solutions – by integrating photovoltaic thermal (PVT) collectors, magnetocaloric and multi-source heat pumps, optimising their performance through advanced control and building energy management systems.

The configuration and design of the multi-source vapour injection heat pump has also been finalised using a low-GWP refrigerant (an HFO: R-1234ze(E)). It is supplied with the most optimal heat either from the outside air, from the PVT collectors or from the ground. The control unit is designed in a way to allow communication with the RES4BUILD building energy management system. A prototype of this heat pump has been manufactured. Initial tests already show a coefficient of performance (COP) of over 5.

Explanatory note: HFO: R-1234ze(E), a mildly flammable (A2L) refrigerant has a GWP of <1 (IPCC AR5 value, normally described as ultra-low GWP) and is widely used as a refrigerant in chillers.
More information about RES4BUILD project is available at