A passive solar building cannot only save cost and reduce energy consumption, but also benefit the harmonious development of society. This paper introduces an optimal design strategy by taking into account its external environment, the building layout, the shape coefficient, the building envelope, and the building structure. An example is given to reveal various concepts and their applications.

In this paper, the feasibility of two low global warming potential refrigerants R513A and R1234yf as alternatives to R134a was tested in an automotive air conditioning system in winter. The test results showed that the heating capacities of R513A and R1234yf were 2% and 4% lower than that of R134a, and their COP were 3-9% and 6-19% lower than that of R134a, respectively. It revealed that R513A can be used as a transition product to replace R134a, and R1234yf required further improvements to improve the energy efficiency.

The application of a mixed refrigerant HFO1234yf/HFC134a (89:11, by mass) of GWP 144 in a vehicle air-conditioner system with and without an internal heat exchanger was studied under refrigerating and heating conditions, and it was compared with an R134a original system. The results show that under refrigerating conditions, the refrigerating capacity of the HFO1234yf/HFC134a system with an internal heat exchanger is increased by 2–4%, which is slightly larger than that of R134a system. The refrigerating COP of the HFO1234yf/HFC134a system with an internal heat exchanger is increased not largely. However, it tends to decrease at high-temperature conditions. In heating conditions, the heat capacity of the HFO1234yf/HFC134a system with an internal heat exchanger is improved by 2–5%, basically equal to that of the R134a system. The heating COP of HFO1234yf/HFC134a with an internal heat exchanger is increased with a maximum of 6% at low-temperature conditions. HFO1234yf/HFC134a can be used as an environmental alternative to R134a as an introduction of an internal heat exchanger into an automobile air-conditioning systems.