Ø  In 1902, Willis Carrier, a graduate of Cornell University, designed the world's first central air-conditioning system for cooling and dehumidifying cold water coils. It was used in a New York printing plant and has since been widely used in textile mills;

Ø  Carrier, the world's first air-conditioner manufacturer, was founded in 1915;In 1922 carrier company successfully developed a landmark position of water cooled centrifugal air conditioner;

Ø  In 1928-1929, air conditioners were installed in the U.S. Congress and then in the White House. After World War II, a large number of air-cooled unit air pipes and air conditioners quickly entered American families, and have been popular up to now;

Ø  At the end of the 1980s, air-source heat pump chill units suitable for Asian demand began to appear in Shanghai market and were first introduced into application by Taiwan companies;

Ø  In 1982, the first generation of refrigerant multilink VRV suitable for Japanese architecture was successfully developed by Daikin. When it entered the Chinese market in the mid-1990s, Dakin's successful marketing strategy made VRV a great success in the Chinese market;

The development of GSHP industry:

Ø  The first record of a ground-source heat pump comes from a Swiss patent from 1912;In 1930s, the geothermal heat pump open system was successfully applied.

Ø  The Edison Institute (ERI) in 1940s and 1950s sponsored research on closed loop systems, but acted slowly in the absence of suitable pipes;

Ø  Since the 1970s, Sweden has been the first successful application of plastic tube as a closed circuit heat exchanger for ground source heat pump system;

Ø  In 1978, the U.S. Department of Energy began investing a large amount of research and development funds in geothermal heat pumps;

Ø  In 1979, the Ground source heat pump system Technology research and development Foundation was established in Oklahoma;

Ø  In 1987, the International Ground source Heat Pump Association (IGSHPA) was founded in Oklahoma State University and began to study the application of ground source heat pumps in the field of project. In 1988, Oklahoma began a commercial rollout of ground source heat pumps;

Ø  In 1994, Geothermal Heat Pump Consortium(GHPC), a non-profit organization established by the ground source heat pump manufacturers and power companies, was established to promote the development of ground source technology. In the same year, the first ground source heat pump air conditioning system of the US government was installed in the Capitol building of Oregon of the United States. Since then, the ground source heat pump began to be widely used in the US government, army and power companies;

Ø  In February 1995, the U.S. Department of Energy and the Chinese Ministry of Science and Technology signed the Protocol on Cooperation in the field of Energy efficiency and renewable Energy Technology development and utilization.In November 1997, the U.S. Department of Energy and the Chinese Ministry of Science and Technology signed Annex VI of the Protocol on Cooperation in the field of Energy efficiency and Renewable Energy Technology Development and Utilization, marking the entry of ground-source heat pumps into China;

Ø  In 2003, the application technology of ground source heat pump began to be commercially launched in China, and gradually gained deep and extensive recognition in various construction fields;

Since 2003, DFUN has become one of the earliest project integrators in China to transform its technology focus to the application of ground source heat pump system.