On April 4, 2019, the State Administration of Market Supervision and Administration and the National Standardization Administration Committee jointly issued the National Standard Bulletin of the People's Republic of China No. 4 of 2019, which approved 21 national standards such as "Lighting Performance of Motor Vehicle Day Driving Lamps". Among them, "Energy Efficiency Limited Value and Energy Efficiency Grade of Air Source Heat Pump (Cold Water) Units with Low Ambient Temperature" (GB 37480-2019) ranked among them. National Standard Item 10. The announcement shows that the national compulsory standard will be implemented on May 1, 2020, and the unit in charge is the National Technical Committee for Standardization of Energy Foundation and Management, and the competent department is the National Standardization Management Committee.            Under the background of steadily advancing the era of "clean heating in winter" in northern China, the release of energy efficiency limits and energy efficiency grades (GB 37480-2019) for low ambient temperature air source heat pump (chilled water) units has great practical significance. It provides the performance requirements, test methods and evaluation basis for local government departments at all levels to carry out bidding and tendering work. It also provides the basis for manufacturing enterprises to produce such products, and greatly ensures the safety, reliability and applicability of such products in practical use. It plays an active role in guiding and promoting the popularization and application of low ambient temperature air source heat pump (chilled water) units, and has a positive significance in regulating the development of the industry.