Increasingly limited sources of fossil energy
are driving people to seek alternative energy resources. The use of
photovoltaic (PV) and biogas for electric power generation continues to be
accompanied by efforts to improve their system performance. Electrical ratings
on PV systems, and the design of the digester in the biogas combustion process,
are two of the relevant issues presented in this edition.

Absorption cooling systems for buildings with
solar power is one type of environmentally friendly system. In addition, the
use of the natural refrigerant propane and a small channel can provide a higher
heat transfer coefficient. In the heating and cooling process, the heat
transfer characteristics are changed due to the phase change of the working
fluids or material. Therefore, research on phase change material or working
fluids has become an important way to support energy savings. Adsorption
cooling systems that work with certain materials have shown better system
performance, are environmentally friendly, and are energy-saving. System
performance is determined by the properties of the material or the working
fluid; it can be improved by modifying the serial or parallel stages of the
process, which can be implemented in the dehumidification process.

The pyrolysis process is another example of an
application of thermofluids that uses flame and combustion; here, a
carbonaceous solid is thermally degraded via heat in the absence of oxygen. For
safety in flame and combustion, controlling the oxygen concentration can reduce
the propensity for ignition and lower the fire propagation rate. Related
applications on the engine and controlling the conditions of combustion in the engine
room can improve engine performance.