A device that forces oxygen (O2) gas into a pressurized cylinder is called an oxygen compressor. Tanks of compressed oxygen are often used by medical patients, or in environments where oxygen levels are unusually low, that raise the percentage of oxygen inhaled in each breath. A compressor is used for filling tanks, while a similar device called a "concentrator" is also common for people who require supplemental oxygen. Though both of these units perform similar tasks, they are not the same.
Oxygen is naturally found in the atmosphere. At sea level, approximately 21% of air is O2 gas while 79% is nitrogen. Typically, this level of oxygen is sufficient. Some medical patients, however, can experience shortness of breath or become lightheaded. A supplemental O2 source can be used to increase the amount of oxygen that enters the lungs.
Unlike a concentrator that requires either electrical or battery power, an oxygen compressor allows O2 gas to be stored and used without requiring a power source. An oxygen compressor allows a patient to refill a high-pressure cylinder. These containers are similar to the air tanks used by underwater divers, but are smaller and more portable. The combination of an oxygen compressor and cylinder gives people the freedom to venture beyond the limits of an electrically powered concentrator.
A large oxygen compressor is often housed at a healthcare facility or hospital, and can be used to refill the O2 tanks of many different patients. Small compressors are also available for home users. These units enable a patient to compress oxygen without having to travel to a dedicated facility. Additionally, a home compressor can be easily transported when the user travels.
The use of oxygen compressors is not limited to the healthcare field. Many industries, including the military, make use of compressors and portable O2 tanks. Aircraft are often equipped with compressed oxygen to prevent blackouts at high altitudes. Compressors are also used to fill the oxygen tanks found in rebreathers. These advanced units are used by underwater professionals to breath underwater without emitting bubbles.
While compressors and O2 tanks have many advantages, they also have several drawbacks. High concentrations of stored oxygen can be dangerous if a flame or spark is present. For this reason, concentrators are sometimes used in place of compressed cylinders for hazardous environments.