High-temperature heat pump for wellness applications using CO2 as a refrigerant.

Number: pap. 2342

Author(s) : SEITZ C. W., LIEBOLD A., SCHÖNFELD H., et al.


Building technology recently has been affected by great innovations to reduce energy demand and to enable self-sufficient operation. To test innovations and prove practicality, EMPA has built a research building called NEST, where different demonstration projects from the building industry can be integrated and scientifically monitored. One of the projects focuses on the sector of wellness applications since it shows significant potential for improving energy efficiency. Usually, spa facilities such as saunas and steam baths are based on direct electric or fossil heating, which is extremely energy intensive and results in high operating costs. In order to establish a more energy efficient technology to provide heat to wellness areas, the present work proposes the usage of a high temperature heat pump with CO2 as a refrigerant. Carbon dioxide is currently favored by many heat pump applications due to the demand for low-GWP refrigerants with non-toxic and non-flammable properties. High-temperature heat pumps with CO2 as a refrigerant are already available on the market and reach supply temperatures of typically up to 100 °C. Wellness applications require temperatures of up to 130 °C on the supply side, which requires new system design. On the consumption side, the heat will be used on a wide variety of temperature levels considering different saunas, showers and space heating. In this context, a stratified storage system ensures the heat output on the desired temperature level. Therefore, the heat exchanger unit as well as the operating range of the heat pump are the major challenges. In cooperation with Scheco AG, a new CO2 refrigerant system has been designed and set up as a part of the EMPA NEST research building by means of a pilot installation including different saunas, steam bath and showers. Measurements are performed to allow the optimization of the overall system.

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  • Original title: High-temperature heat pump for wellness applications using CO2 as a refrigerant.
  • Record ID : 30024512
  • Languages: English
  • Source: 2018 Purdue Conferences. 17th International Refrigeration and Air-Conditioning Conference at Purdue.
  • Publication date: 2018/07/09


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