Prototype CO2 HVAC unit developed with ejectors
r744.com, July 6, 2017
In a competitive residential air conditioning market traditionally dominated by HFCs, the researchers hope the MultiPACK will help CO2 to become a commercial reality in this field of application. “We are looking for partners interested in a demonstration site (in a hotel, spa, etc.,” said Armin Hafner of SINTEF (Foundation for Scientific and Industrial Research at the Norwegian Institute of Technology in Trondheim, Norway), who developed the MultiPACK CO2 HVAC unit with other participants in the European project.
The MultiPACK project aims to utilise the multi-ejector in the unit “for expansion work recovery,” Hafner and Silvia Minetto of the National Research Council in Padova, Italy write in their paper. It can operate in four different heating and cooling modes.
The prototype – developed with the help of enEX and Danfoss – is a reversible HVAC system with a multi-ejector and can be used as a heat pump. It features cooling, cooling with hot water production, and hot water production modes.
The pack is designed to heat and cool buildings even in warm ambient climates with CO2 as the working refrigerant. “This is something you can do easily with CO2 systems,” Hafner explained.
Once six installations have taken place in sites in southern Europe, they will be measured for performance, levels of indoor comfort and sanitary hot water demand.
Training material will also be provided for end users and contractors under the project, so the units can be installed easily in the future.
The paper, called the Multipack: demonstration of the Next generation of standardized integrate cooling and heating packages for commercial and public buildings based on environmentally friendly carbon dioxide with vapour compression cycles by Hafner and Minetto, was presented by Hafner at the XVII European Conference on the latest technology in refrigeration and air conditioning in the Italian city of Milan (9-10 June 2017).
The conference was organised by the United Nations Environment Programme (UNEP), International Institute Of Refrigeration (IIR), the Italian refrigeration association (Associazione Tecnici Del Freddo), the Italian refrigeration study centre Centro Studi Galileo, the European Energy Centre and the European Centre of Technology.