Solar Engineering of Thermal Processes, 4th Edition

Chapter 15

Solar Cooling

The use of solar energy to drive cooling cycles has been considered for two related purposes, to provide refrigeration for food preservation and to provide comfort cooling. In Section 15.1 we briefly review some of the literature relating to both of the applications, since there is a common underlying technology. From then on, we concentrate on problems relating to solar air conditioning. In particular, for application in temperate climates, we address questions of the use of flat-plate collectors for both winter heating and summer cooling.

Solar cooling of buildings is an attractive idea. Cooling is important in space conditioning of most buildings in warm climates and in large buildings in cooler climates. Cooling loads and availability of solar radiation are approximately in phase. The combination of solar cooling and heating should greatly improve use factors on collectors compared to heating alone. Solar air conditioning can be accomplished by three classes of systems: absorption cycles, desiccant cycles, and solar-mechanical processes. Within these classes there are many variations: for example, using continuous or intermittent cycles, hot- or cold-side energy storage, various control strategies, various temperature ranges of operation, different collectors. Each of these methods is reviewed in this chapter, with emphasis on absorption and desiccant cooling.

The future of many of the methods will depend on developments beyond the cooling process itself. ...