Is it true that room air conditioner does not replace the room air with some fresh one from the outside?

Question

I hear it only changes the room temperature but not the air itself,while I thought otherwise.Then how does enough oxigen get into my place?

Answer 1

It does change the air by removing its humidity which causes the air to cool down. Some air conditioners also affect the temperature directly by heating it up or cooling it down, as required.  And some do bring in fresh air from outside.

You don't really have to worry about the amount of oxygen in the air.  Windows and doors get opened all the time, which brings in fresh air.  And even if you don't leave your house for a while, oxygen comes through walls and windows, and chemical processes produce some, too.

Answer 2

Most room ACs have a setting to recirculate or to bring in fresh air.  

Answer 3

Some do and some don't. Some room AC's have an air mix feature. However a whole house AC only recirculates the air in the house. But since no house is airtight you needn't worry. Besides, when you enter and leave throughout the day, air is also exchanged.

Answer 4

Most have a setting for VENT, or say OPEN, CLOSED somewhere on the outside or beneath the cover.  If it's hot though, you'll be bringing in hot moist air and make the house much harder to cool.