To date, solar air-conditioning is still far away from market penetration. A survey in 2004 contained about 70 realised applications, nearly 70% of them were closed cycle chilled water systems, mainly equipped with a thermally driven absorption chiller. The smallest system size was limited to approx. 35 kW due to the available chillers. Experiences from this operational stage of solar air-conditioning in large and medium-sized systems were collected and published within Task 25 of the Solar Heating & Cooling Programme of the IEA [1] and within other projects, e. g., [2]. A general overview on the applied technologies is given in [3]. Promising applications of SAC exist. Nevertheless, many problems remain to solve, mainly addressing the optimisation of the system

control, to elaborate standardised system schemes, and to promote the solar air-conditioning technologies. Activities especially in pre-engineering of small systems and on recommendations for custom made large systems are in the focus of the new Task 38 of the IEA, Solar Air­Conditioning and Refrigeration [4]. Here, the SOLAIR project fits well with its promotional work concentrating on small (< 20 kW chilling capacity) and medium-sized applications. This focus is of special interest, since recently a number of European manufacturers went on the market with new small chiller developments in the capacity range between 4.5 kW and 30 kW.

A survey on current and available small and medium-sized SAC appliances has been elaborated by the SOLAIR consortium including a review of monitoring experiences and the identification as well as an analysis of successful running systems [5].

Within SOLAIR, data from successful running applications on solar cooling and air-conditioning in the small and medium cooling capacity range were collected. Table 1 summarises briefly the content of this database. More details are given in the cross-country analysis report of the database within SOLAIR [6].

To motivate potential market actors and contribute to a stronger market implementation, the future market potential of small and medium-sized SAC appliances was analysed. The analysis was focused on the definition of the areas of application, on the legal frameworks and subsidy schemes as well as on the identification and description of customer and investor groups [7].

From this study it was possible to conclude that there is a great potential in the residential housing sector for SAC. There are 61,317,627 residential buildings in total in the project partner countries. Quite a share of them is multi-family houses. These buildings are the most appropriate for small and medium sized solar cooling systems. The share of privately owned buildings in this sector is also large so the financing parties are in most cases private investors. Specially Italy, Spain and Portugal, which are the most appropriate countries for using solar energy for cooling, have a great share of 90% privately owned flats. In this case the most important effort to promote SAC is to motivate the private sector for renewable energy sources showing qualities and financial benefits of solar cooling.