Demand for space cooling systems is growing worldwide. The main reasons are socioeconomic developments such as the growing world population and the rise of economic wealth, especially in developing countries. These developments run simultaneously with global warming effects, increasing the need for cooling. This study introduces the development of the Cooling Demand Market Index (CDMI), which indicates the demand for cooling appliances worldwide at a spatial resolution of 1 km. It is based on population density, Gross Domestic Product (GDP)/capita and Cooling Degree Days (CDD) per climate zone. The CDMI is calculated for 2020 and 2050 in four different future scenarios in accordance with the Spatial Socioeconomic Pathways (SSP) and Representative Concentration Pathways (RCP). Further, the Solar Thermal Cooling Index (STCI) was developed to spatially estimate the worldwide potential to use solar thermal cooling systems based on solar availability and limitations due to maximum heat rejection temperature. Results of the CDMI show that the economic demand for cooling solutions is increasing, especially in developing countries, and that India will be by far the largest market by 2050. Countries such as Burundi and the Democratic Republic of the Congo show the strongest national increases in CDMI. The STCI indicates that ammonia absorption chillers and zeolite adsorption chillers can serve the vast majority of the market thanks to their capability to run at high condenser temperatures.

The University of Technology, Sydney (UTS) has built a unique tri-generation system that provides chilled water, hot water, and electricity to their new Faculty of Engineering and Information Technology (FEIT) building. It integrates parabolic trough collectors, flat plate collectors, photovoltaic panels, and wind power as generators with thermal and chemical energy storage. The heat from the parabolic trough collectors is used to run a small-scale Organic Rankine Cycle (ORC) unit as well as a small-scale ammonia/water absorption chiller to provide either electricity or chilled water, respectively. The condenser heat from both units is fed into the domestic hot water (DHW) supply of the building in addition to the solar heat from the flat plate and the parabolic trough collectors. The design concept including the main system components and the system control strategy are described in detail. Further, the lessons learned during the installation and commissioning of the complex tri-generation system are given. As a novelty in this area, the tri-generation system has been specifically designed to allow students and researchers to work with it, hence this paper also describes the wide range of teaching opportunities for undergraduate and graduate engineering students as well as post-doc researchers

This paper presents the results of the activities related to the subtask “Building and process optimization” of the IEA SHC Task 65. The main topic of this activity was the integration of solar cooling in retrofitted HVAC systems. Based on the current conventional HVAC systems, the integration may present difficulties concerning cold distribution and refrigerants. Cold supply systems can also reduce airflow in air-based systems and enhance thermal comfort in buildings. The best technical actions for specific scenarios were mentioned considering both technical and economic aspects. Unfortunately, not all the analyses that were planned provide useful data. Results show that there are few recent projects that consider the application of solar cooling systems in buildings and most of them are based on simulation. Moreover, not much data about the characteristics of the buildings (envelope, other cooling systems, comfort conditions, etc.) are reported in the studies. This is because many of them are more focused on the plants’ configurations, and the performance of the different plants is in general assessed by testing the prototype in a single room. Despite this, the information provided could be used as baseline cases in order to study the potential energy savings achievable by applying solar cooling systems.