With passing of time, spaces used for residential and business purposes are becoming increasingly blocked off from outside space due to development of air conditioning, insulating and noise blocking facilities. This also led to decrease in ventilation rate, therefore indoor residential space is becoming more and more inferior. Also, due to limitations of space, many facilities are being installed in underground area lacking ventilation.
Most of intelligent buildings of the latest trend are designed with windows not to be opened. Therefore, opinions are being raised that indoor environment is not as good as before.
In general, we believe that outdoor air is more polluted than indoor air in urban areas. However, in reality, it is clear that indoor air is certainly more polluted than outdoor air.

Oxygen concentrator system of OXUS basically consists of the system that is the same as air conditioner.
It consists with an outdoor unit, indoor unit and controller. Also, piping and installation operations are necessary. Outdoor unit is installed outdoors or in balcony. By separating oxygen and nitrogen from the air, nitrogen is discharged and the oxygen created is sent to an indoor space through pipeline. Indoor unit injects oxygen into the space. In other words, only the necessary oxygen is sent into the requiring space by using outside air.

The average oxygen concentration throughout the world is 20.9%. Oxygen concentration is lower in polluted areas. Human beings experience a sense of stuffiness in oxygen concentration level of less than 20%. Indoor space of an urban region in which most people reside has the oxygen concentration of 20.5% in general. However, the level easily drops below 20% if ventilation is not carried out successfully or the space is occupied by a large number of people. In general, difference in oxygen concentration between inhalation (20.9%) and exhalation (16%) of a human being is approximately 4.9% on average. Aggravation in environmental conditions leads to decrease in oxygen concentration of inhalation. Therefore, the difference from that of exhalation decreases. As a result, human body, especially brain, feels as though the oxygen is insufficient by as much as 20% rather than by an actual 1%. Even is oxygen room products discharge oxygen to an indoor space, it is not easy to have the oxygen concentration level surpass 22%. However, the 1% of increase in oxygen concentration means approximately 20% of increase experienced by our body.