Included in the most basic and everyday products, toasters, space heaters and other small heat generation appliances are often fitted with flat ribbon coils or other heat coil shapes. Consumer and industrial ovens can be fitted with ceramic-coated heat coils; the ceramic material shields the coils from dripping grease or other contamination. Clothing dryers, hair dryers, industrial dryers and many other kinds of heat generation and moisture removal equipment are equipped with heat coils as their heat generation mechanism. Heat coils can be used in water heaters, and furnaces can employ a combination of heat coils and air blowers to heat air and then transmit it throughout a series of ductwork.
Coil heaters may be bent to a custom size or shape, including round, coiled and spiral wound, which are used when high temperatures are needed in confined areas. Star wound coils are placed in pipes and ducts to create a turbulent flow in air or liquid. They are used in a number of applications in the heating, plastic manufacturing, food processing, textile, and paper processing industries. Holding tanks, blow molding machines, extruders, bag sealing, and hot metal forming punches all use coil heaters. Operating on AC voltages, coil heaters provide a uniform heat pattern over a wide area up to 1200°F. They are annealed and made of aluminum, brass, copper, iron nickel or steel exterior and ceramic, mica or fiberglass insulation.
Depending on the metal, some coil heaters are corrosion resistant and may be immersed in heated substances or used in cryogenic applications. They come in different shapes and sizes, including flat, round, mini, which is the smallest available, maxi, which is the largest and most durable, and low profile, which is flat. Some are made with a lock positioning ring, which makes installation easier, or are cast in brass, which is useful in nozzle-to-nozzle repeatability.