In the winter, probably all dwellings tightly closed so as not to got to the inside of the cold air. However, in the apartment where the heat is emitted by gas or coal stoves, which they collect a lot of oxygen, lived in this way may be to hypoxia organism. Other problems occur in hot and humid climate. People residing in areas nagrzanych feel niekomfortowo, and at high temperatures prevailing outside the window opening does not solve the problem. In other homes the problem is also a separate kitchen. During the cooking there accumulates a large amount of water vapor. This makes it difficult to increase the elimination of humidity. If you are using the gas stoves without proper ventilation, it is a significant reduction in oxygen content, as it burns in the burner flames.