Chillers use a refrigerant or working fluid in a two-phase refrigeration cycle. Copper conducts heat up to 8 times better than other metals, such as steel and aluminum. Copper tube is relatively easy to manufacture and form. Copper tube can be easily bent, fitted, and joined. Copper resists corrosion and requires little maintenance, a very important consideration in a closed system with a 20-30 year life expectancy.
Copper has the strength required to withstand fluid pressures in large air conditioning systems.
To a building owner, the key difference between mechanical and absorption chillers is the type of energy used. Mechanical compression chillers typically rely on electrical energy, while absorption units require a source of heat, for example, natural gas, hot water, or steam. Absorption units are installed when the available heat source is more economical than electricity. They account for a very small portion of total installed capacity. There are three basic types of mechanical compression chillers.