Saren Minds1* and Klaus Ellehauge2

1 AC-Sun, Rudolfgaardsvej 19, DK-8260 Viby J, Denmark
2 Ellehauge & Kildemoes, Vestergade 48 H, 2s. tv., DK-8000 Aarhus C, Denmark
* Corresponding Author, smi@ac-sun. com

Abstract

This AC-Sun is in the process of developing a solar powered AC unit which only consumes 10% of the electricity of a conventional AC unit. The devise consists of a traditional thermal solar panel that heats water to temperatures between 75-95°C. An expander, based on a Rankine — process, uses the energy from the solar panels to operate a compressor, which through a Carnot — process cools air in traditional air coolers. The process uses water as cooling agents both in the expander and the compressor and therefore is environment friendly. The core of the research and development project is the patented process, which consists of leading the energy from the compressor outlet back to the steam temperature on the inlet duct of the expander. The internal heat recovery ideally improves the system efficiency for cooling purposes compared to other similar systems. The developing process comprises design and production of process equipment and processing forms for paddle vanes and turbine casing as well as internal heat exchangers. A world-wide patent for the principles behind the solution has been approved through a PCT testing. The proto type test is ongoing in — August / September 2008.

Keywords: AC-Sun, Solar Air Conditioning, Rankine process, expander, turbo compressor

1. History

The project AC-Sun started at year 2005 with the mission to develop and commercialize a thermal air conditioning solution driven by solar panels. The novelty of the product is great due to considerable power savings (a factor 10), free-of-pollution, silent cooling and better comfort.

The technical content consists of research and development of a turbo expander/ compressor which is working with water as a process agent under low pressure and temperatures, and where the heat production from low temperature thermal solar panels is transformed into a low temperature compressor, which is used for cooling of air in an air conditioning device. The success criterion is to exploit a series of thermal processes, which by them selves are well-known, but never previously have been combined to one functioning unit. The world-wide patent on the principles behind the solution is entering the national phase and the company has taken the process to a stage where proof-of-concept has been achieved.