How often is the air inside a Salounge exchanged with fresh air?

Many of the traditional salt caves do not exchange the air during sessions. After a 45-minutes session, when people have left the room, they exhaust all the air and blow in fresh air during a period of about 15 minutes. This air has a room temperature but it is not dried. Depending on the relative humidity from the outside air, the air can be relatively dry or pretty humid.
Microsalt constantly exchanges air inside the room, also during sessions to make sure people inhale clean air. This is done by means of an advanced air treatment system. The Microsalt air treatment systems can cool, heat, and dehumidify constant fresh air. Drying constantly is the most important factor for the creation of a clean and high quality salt aerosol environment. Microsalt does this by means of adsorption drying technology.