Energy sustainable development through energy efficient heating devices and buildings
Energy devices and buildings are sustainable if, when they operate, they use sustainable (renewable and refuse) energy and generate nega-energy. This paper covers three research examples of this type of sustainability: (1) use of air-to-earth heat exchangers, (2) computer control of heating and cooling of the building (via heat pumps and heat-recovery devices), and (3) design control of energy consumption in a house.
Cooling energy evaluation for high-rise residential buildings in Hong Kong
Based on the design of a typical high-rise public housing block in Hong Kong, the dependence of space cooling loads of residential flats on the constructions of external walls and partitions, and the location of thermal insulation layer in the walls and partitions, was studied by detailed simulation. The results show that insulating the envelope and the partitions would be effective in reducing the yearly space cooling load, by up to 38%, but could either increase (by up to 19%) or reduce (by up to 16%) the peak cooling demand, depending on the number and positions of insulation layers in the walls. Reducing the thermal capacity of the envelope and partitions (e.g. by reducing their thickness) would lead to large increases in the peak cooling demand, by more than 60% in the extreme case.
Physical Principles of Wind Energy Conversion
The primary component of a wind turbine is the energy converter which transforms the kinetic energy contained in the moving air, into mechanical energy. For the initial discussions of principles, the exact nature of the energy converter is irrelevant. The extraction of mechanical energy from a stream of moving air with the help of a diskshaped, rotating wind energy converter follows its own basic rules.