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Trigeneration systems based on heat pumps with natural refrigerants and multiple renewable sources.

Project description

Reducing energy costs via natural refrigerants

The fight against global warming necessitates us finding ways to reduce the costs of heating, cooling and electricity in cities. The EU-funded TRI-HP project will offer tailored solutions for European multi-family buildings. The Trigeneration systems use heat pumps with natural refrigerants and a wide range of renewable sources. Energy use is optimised through innovative controls and three heat sources: solar, ground and air. The purpose of the project is to reduce the costs by up to 15 % in comparison with the existing heat pump technologies and decrease greenhouse gas emissions from gas boilers and air chillers by 75 %.


The overall goal of the TRI-HP project is the development and demonstration of flexible energy-efficient and affordable trigeneration systems. The systems will be based on electrically driven natural refrigerant heat pumps coupled with renewable electricity generators (PV), using cold (ice slurry), heat and electricity storages to provide heating, cooling and electricity to multi-family residential buildings with a self-consumed renewable share of 80%. TRI-HP systems will include advanced controls, managing electricity, heat and cold in a way that optimizes the performance of the system and increases its reliability via failure self-detection. The flexibility will be achieved by allowing for three heat sources: solar (with ice/water as storage medium), ground and ambient air. The innovations proposed will reduce the system cost by at least 10-15% compared to current heat pump technologies with equivalent energetic performances. Two natural refrigerants with very low global warming potential, propane and carbon dioxide, will be used as working fluids for adapted system architectures that specifically target the different heating and cooling demands across Europe. The newly-developed systems will find application in both new and refurbished multi-family buildings, allowing to cover the major part of Europe’s building stock. The new systems reduce GHG emissions by 75% compared to gas boilers and air chillers. The TRI-HP project will provide the most appropriate knowledge and technical solutions in order to cope with stakeholder’s needs, building demand characteristics, local regulations and social barriers. Two system concepts will be developed for two different combinations of heat sources, i) dual ground/air source and ii) solar with ice-slurry as intermediate storage. These two concepts combined with the two heat pump types developed (CO2 and propane) will lead to three complete systems (CO2-ice, propane-ice and propane-dual) that will be tested in the laboratory.

Call for proposal


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Sub call



Net EU contribution
€ 1 120 055,09
8640 Rapperswil

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Schweiz/Suisse/Svizzera Ostschweiz St. Gallen
Activity type
Higher or Secondary Education Establishments
Total cost
€ 1 120 055,09

Participants (11)