Solar cooling machine with a cooling power of 2 kW

Development and building of a prototype of a coolingmachine with a cooling power of 2 kW, tests and optimizing on a test facility, connection to a solar unit and utilization for air conditioning.

Content Description




According to an EU study with the topic "Energy efficiency for room air conditioners" the trend to room air conditioners increases significantly in Europe. In 1996 in the whole EU region about 7,4 mio room air conditioners where in work. This corresponds to a total energy consumption of 11 TWH - or the electric power consumption of about 3 mio Austrian homes. The study assumes that till 2020 even about 33 mio room air conditioners will be operating. If till then no efficiency political measures will be taken, the total energy consumption caused by room air conditioners will be about 28,3 TWh in 2010 and will rise to 43,9 TWh till the year 2020.

The new absorptions cooling system - developed and patented by Dr. Gerhard Kunze - means a substantial technological advancement in cooling technology as it has a significant advantage compared to the conventional Platen Munters cooling principle ("Electrolux refrigerators"):

  • While the Platen Munters system has to be powered with temperatures of about 150°C Dr. Kunze's improved technology delivers cooling energy already when powered with temperatures of about 75°C.

Thus completely new applications in the field of cooling are possible, mainly

  • the use of solar energy from conventional flat collectors,
  • the use of waste heat with a quite low temperature level.

An especially interesting market segment for the SolarFrost technology are low energy houses where normally solar units (with surplus energy in summer) and controlled ventilation are installed. With the additional comfort of cooling in summer the acceptance for controlled ventilation can certainly be improved.

The most important advantages of the new technology are:

  • Energy source can be any supply of hot water or hot air (75°C)
  • It can be integrated into existing solar systems, running just on surplus energy.
  • Refrigeration temperature as low as -30°C
  • High energy efficiency (30-60% according to refrigeration temperature)
  • Various different applications are possible (air conditioning, cooling boxes for vaccines, warehouses for agricultural products, etc.)
  • No greenhouse or ozone-layer active gases
  • Simplicity, no need for sophisticated regulation and control systems
  • No moving parts, that could wear out
  • No noise
  • Negligible maintenance and repair - "install and forget it"
  • As simple and as cheap as the classical "Servel" or "Electrolux" refrigeration system
  • May be built to any size

As the patented cooling machine already works successfully in an experimental unit with a cooling power of about 200W, in this project we will

  • develop a prototype with a cooling power of about 2 kW,
  • test an optimize it on a test facility,
  • connect it to a solar unit
  • and finally use it for air conditioning.

The research project will be accomplished in close cooperation with the solar company SOLID.

Economic meaning

Solar cooling is a central topic for a sustainable energy policy.

In Austria in 1999 the 2 mio square meter mark for installed thermal solar collectors surface area was exceeded. Thus Austria takes a leading position compared to the other member states of the European Union. About 27% of the installed collectors are used for warming swimming pools, the remaining 73% are almost exclusively used for water heating and heating support for one- and two family houses.
In countries with hot climate the biggest contribution to the energy bill is for cooling. Since the energy crisis in the 70ties solar cooling is a main research topic. Anyway, up to now no remarkable progress has been reached, solar cooling has been too expensive in comparison to conventional methods.

Therefore Dr. Kunze's inventions is a milestone and a crucial technological advancement in the field of cooling technologies.

Via our website more than 150 companies, organisations and individuals have expressed their interest for the SolarFrost technology - e.g.

  • companies like Austria Email, SOLID, F.M. Zumtobel Holding & Consulting GmbH, Dometic (former Electrolux), Borosil Glass Works Ltd. (the biggest glas production in India, also produce solar collectors) etc.,
  • NGOs like Greenpeace International,
  • International research institutes and universities.

The SolarFrost technology shall be spread by technicians who will be trained in Workshops we will organize. These technicians shall be the basis for a worldwide operating network.

Project Partners

Project manager: Gerhard Kunze
SolarFrost Forschung Dr. Kunze OEG

Ernst Meissner
SOLID Gesellschaft für Solarinstallation und Design GmbH


Dr. Gerhard Kunze
SolarFrost Forschung Dr. Kunze OEG
Wiener Straße 69
A-3002 Purkersdorf
Tel.: +43 (2231) 61812
Fax: +43 (2231) 61832