$8.(10$ points$)$ Air conditioners, refrigerators, humidifiers and dehumidifiers operating on thermodynamic principle are widely used in residential, office and commercial building. With the increasing globalization, the products available in market could be manufactured in USA, Japan, Korea and China, which raise the concerns to safety, maintenance and parts availability and requires the development of international standard. Please describe the importance of international standards associated with the air conditioners, refrigerators, humidifiers and dehumidifiers especially the thermodynamic system such as the safety operation pressure, quality of coolant, standard parts such as throttling valve, compressor, or even condensing tubes. Please also comments if the development and implementation of international standard helps to reduce the production and maintenance cost.