Solar hybrid air-conditioning design for buildings in hot and humid climates - Solar Energy Sciences and Engineering Applications - page 491

water pumps and auxiliary heaters, one for the heat-driven chiller and the other for
the desiccant cooling cycle.
15.2.3.2 SHAC enhanced by high temperature cooling
In this approach the energy performance of SHAC is further facilitated by using the
appropriate strategies of high temperature cooling, such as radiant ceiling cooling or
a specific indoor ventilation method. Since this allows a higher chilled water supply
temperature from the heat-driven refrigeration system, a better solar fraction of the
solar energy system and a higher coefficient of performance of the refrigeration cycle
is achieved.
15.2.4 A hybrid approach to energy sources and system design
15.2.4.1 SHAC with dual solar energy sources
In this design, photovoltaic/thermal (PV/T) panels are utilized, and cogeneration of
electricity and heat can happen. The solar electric gain can be used to drive the
compression chiller for the zone cooling load, while the solar-thermal gain can regen-
erate the desiccant cooling for the ventilation load (Fong et al., 2010b), as depicted
in Figure 15.2.6. A power regulator is used to allow the power to come from either
the PV panels or the regional grid. In this case, both auxiliary electricity supply and
auxiliary heating are involved.
15.2.4.2 SHAC system with separate thermal and electrical energy sources
An alternative of this hybrid approach is to make use of the solar-thermal gain for
fully regenerating the desiccant cooling, using electricity from the grid for the conven-
tional compression chiller. Figure 15.2.7 illustrates the SHAC system energized by the
separate thermal and electrical energy sources.
Figure 15.2.6 SHAC system with both electricity and heat generation.