Review of passive solar heating and cooling technologies Hoy-Yen Chan *, Saffa B. Riffat, Jie Zhu Department of the Built Environment, University of Nottingham, University Park, Nottingham NG7 2RD, UK Contents 1. Introduction ..................................................................................................... 781 2. Passive solar air heating and natural ventilation via buoyancy effect........................................................ 782 2.1. Trombe wall ............................................................................................... 782 2.2. Solar chimney .............................................................................................. 785 2.3. Unglazed transpired solar facade ............................................................................... 785 2.4. Solar roof .................................................................................................. 786 3. Passive solar cooling via evaporative effect ............................................................................ 786 3.1. Evaporative cooling.......................................................................................... 786 3.1.1. Direct evaporative cooling (DEC) ....................................................................... 786 3.1.2. Indirect evaporative cooling (IEC) ....................................................................... 787 3.2. Building integration of evaporative cooling....................................................................... 787 4. Passive solar: filling the gap of active solar technologies ................................................................. 787 5. Summary ....................................................................................................... 788 Acknowledgements ............................................................................................... 788 References ...................................................................................................... 788 1. Introduction Generally, building sector consumes 35.3% of final energy demand [1]. Parts of the major energy consumption in buildings are the heating, ventilating, and air-conditioning (HVAC) systems. They are indoor climate controls that regulate humidity and temperature to provide thermal comfort and indoor air quality. With total amount of this HVAC’s energy consumption in buildings, whether is the space heating or cooling being the dominant, they are closely related to the local climate condition. Heating systems are to provide or collect and store the solar heat, and retain the heat within the building. In contrast, cooling systems are to provide cold or protect the building from direct solar radiation and improve air ventilation. Space heating is the most important building energy user in cold countries, whereas, air conditioning is a major contributor to peak electricity demand in hot climate countries or during summer. For instance, in the United Kingdom, energy used for space heating was about 50% of the service sector energy consumption in 2004 [1,2]. On the other hand, air-conditioning load accounts for 40% of peak load during the summer in Shanghai. These heating and cooling loads are having an impact on CO 2 emissions, as well as on security of energy supply [1,3]. Therefore, Renewable and Sustainable Energy Reviews 14 (2010) 781–789 ARTICLE INFO Article history: Received 20 October 2009 Accepted 27 October 2009 Keywords: Passive Cooling Heating ABSTRACT Heating, ventilating, and air-conditioning (HVAC) are parts of the major energy consumption in a building. Conventional heating and cooling systems are having an impact on carbon dioxide emissions, as well as on security of energy supply. In this regard, one of the attempts taken by researchers is the development of solar heating and cooling technologies. The objective of this paper is to review the passive solar technologies for space heating and cooling. The reviews were discussed according to the working mechanisms, i.e. buoyancy and evaporative effects. The advantages, limitations and challenges of the technologies have been highlighted and the future research needs in these areas have also been suggested. ß 2009 Elsevier Ltd. All rights reserved. * Corresponding author. Tel.: +44 115 951 3158; fax: +44 115 951 3159. E-mail address: laxhyc@nottingham.ac.uk (H.-Y. Chan). Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser 1364-0321/$ – see front matter ß 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.rser.2009.10.030