Solar-desiccant air-conditioning systems - Solar Energy Sciences and Engineering Applications - page 537

controls. The most practical application is the desiccant material used in the control
of moisture in sensitive products such as foods. The uptake of moisture is natural as
can be observed. Since the process is exothermic, removal of moisture is done mostly
using thermal energy, while some is removed through reduction of pressure.
For the control of large spaces, such as industrial areas, assembly of complicated
and sensitive electronic, electrical, chemical and mechanical systems, and application
of the desiccant-based air-conditioning system is done using thermal energy. It should
be noted that application of the technology in the commercial sector is undertaken in
the same way as for industry, but with some variations.
For residential buildings the technology is still at the infant stage, but as the devel-
opment of larger, ideal systems reaches the middle stages of development, smaller-scale
systems will surely follow on in due course, along with the incorporation of other
processes for optimization.
Several combined systems have been developed, such as Combined Heat and
Power (CHP) and Combined Cooling, Heating and Power (CCHP) along with the
Distributed Energy System (DES), the purpose being cost-effective implementation
and optimization of the technology. In the combined systems the electricity generated
is used for different applications, while thermal energy is used for the operation of
sorption air-conditioning. This means that the systems provide heating, cooling and
power production, and thus have higher overall system efficiency. In other systems
the technology is coupled with other devices such as waste-thermal energy from from
industrial, commercial or natural processes. This is dependent on the availability of
thermal energy sources, and thus design is based upon it.
Some are coupled with thermal energy produced from the utilization of clean
energy sources such as solar energy, biogas or biomass, or other forms. In addition,
utilization of cheaper night-time electricity is used through thermal storage done in
sensible or latent storage systems. Storage of unutilized thermal energy from differ-
ent thermal energy sources, particularly given its variable availability, is indeed an
approach that should be optimized from both economic and practical standpoints.
Other designs are based on the combined operation and utilization of available clean
energy sources, waste-thermal energy sources or conversion of night-time electricity for
thermal storage. This is dependent on the needs and considerations within the design
process.
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Ahman, M., Lundin, A., Musabasic, V. and Soderman, E. (2000) Improved health after
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