Steamers create steam from heated water which the user pours into the unit. The base of the unit is made of a large, hollow container (generally plastic) with a hole and removable lid. The user pours water into the unit to fill it. Though tap water can be used, some steamers require distilled water to avoid mineral buildup inside the machine. In order for the steamer to operate properly, the water compartment should not be filled to the brim as a few inches need to be left at the top to allow the steam to gather and prevent the water from sloshing into the tubes.
Steamers are powered through conventional home electricity. Heat is produced by a metal heating element below the water storage container, similar to that on an electric stovetop. This element is just hot enough to heat the water to the point of steaming but not bubbling. When this happens, the steam will naturally travel to the top of the container and through the only available exit, which leads into the steamer's tubing systems. For this reason, the water compartment should be positioned below the tubing; this is why many steamers are made in the form of low water chambers mounted to carts with tall wire stands that hold the hand-held portion higher.
The tubing on a fabric steamer is insulated against the heat of the steam. This prevents the user from getting burned by the heat as the steam travels through the tubes. On a high quality steamer, the tubes are also made to be thick enough so that they won't easily bend and kink, blocking the passage of steam.
The handle portion of the steamer is where the steam is released and the flow directed into the fibers of the garment. Some steamers are simply hollow heads with holes that release steam constantly while more advanced machines have a release valve that allows the flow of steam to stop and start.
When clothing is immersed in steam, the hot particles will saturate the fibers of the garment. This causes the fibers to relax because they are weighted down by the minute amount of hot water. The cloth pulls straight with the weight of the steam saturation then dries seconds later in the stretched position, eliminating the wrinkles. The thicker the cloth, the more steam must be applied to saturate it.