NxtHPG: Next Generation of Heat Pumps working with Natural fluids

Jun. 05, 2014

NxtHPG project (www.nxthpg.eu; GA number 307169) is targeted at producing a definitive step forward to the launch of a high capacity heat pump technology employing natural refrigerants, that can become the future solution for heating and cooling on both new and existing buildings, with full capabilities for integration into the future energy systems of the buildings, significantly contributing to transformation of the Sector into renewable and efficient system and to the minimization of EU energy consumption and CO2 emissions.

The main objective of the project is the development of 4 to 6 reliable, safe, high efficiency and high capacity heat pumps (>40 kW) working with the two most promising natural refrigerants: Hydrocarbons and CO2, together with a set of improved components and auxiliary devices adequate for the efficient and safe use of the two refrigerants.

The project aims to reach a higher efficiency (10-20% SPF improvement) and lower Carbon footprint (20% lower TEWI) than the current state of the art HFCs/HFOs or Sorption heat pumps. The costs shall be very similar or slightly higher than the latter systems (10%). In this context, natural refrigerants (Hydrocarbons and CO2) were selected due to their low GWP (Global Warming Potential) and its ODP (Ozone Deplection Potential) equal to zero.

The project will also focus on the development of an efficient capacity modulation in order to enhance the integration capability with other renewable sources in the energy systems of Buildings and Industry. In this sense, if the project is successful, it will clearly bring a definitive step forward to overcome the barriers holding back the spread of natural refrigerants by proving that a new generation of heat pumps based on HCs and CO2 is perfectly feasible and commercially competitive.

The total duration of the project has been planned as 4 years, and it started on the 1st of December 2012.

NxtHPG Project update:

The first objective of the project is the identification of the cases in which the use of natural refrigerants can lead to cost effective and high efficient solutions with a fast commercial exploitation and later to the successful deployment of the technology to other sizes, ranges and applications.

The selected applications in which the use of a natural refrigerant solution is clearly feasible and shows clear advantages from the environmental and efficiency point of view, as well as a high potential of commercial exploitation by the European Heat Pump Industry were finally decided and presented in the latest EHPA newsletter of June 2013 for both selected natural fluids: Hydrocarbons and CO2. Once the case studies were identified, the definition of the operating conditions, refrigerant, capacity and the design requirements were compiled in the form of a deliverable D1.3 ‘Description of the selected case studies’ at the end of June 2013.The next table (Table 1) presents an executive summary.


 Once the definition of the case studies was completed, the selection and design of components was performed by each of the implied manufacturers (CO2 team: ENEX, LU-VE , ALFA-LAVAL and DORIN; HCs team: CIAT,LU-VE, ALFA LAVAL and DANFOSS-CC) together with the RTD centers (CO2 team: ENEA, EPFL,UNINA and NTNU; HCs team: UPVLC, KTH, and EPFL), with the use of the commercial software IMST-ART (http://www.imst-art.com/) developed by UPVLC to assist in the design of HP prototypes based on the optimal selection of components in the framework of WP3 ‘HP prototypes design’. The objective of the design was mainly focused in obtaining the highest possible efficiency that meets all the design and safety requirements specified in WP1 ‘Analysis of applications and case studies definition’. The preliminary design of each prototype was done for the nominal operation point also taking into account the whole range of working conditions. The next tables (Table 2 and Table 3) show the results of the preliminary design (which will be improved during the project) considered for each prototype with an indicative value of the COP expected in heating mode.


The final heat pump prototypes were ready at the end of April 2014 and the first experimental campaign will take place at KTH (Stockholm, Sweden) for CASE 1 and CASE 2, UPVLC (Valencia, Spain) for CASE 3, and ENEA (Rome, Italy) for CASE 4 and CASE 5 until the end of November 2014. Results of the experimental campaign will be considered to update the HP models already developed in WP2 ‘Modelling of heat pumps and systems’, and a first assessment will be carried out at the end of November 2014.


For more information please visit http://www.nxthpg.eu/home/