The humidity is the amount of water vapor in the air. It is measured in percentages. The normal level of humidity in air is around 30 to 50%.
The purpose of an HVAC system is to control the temperature and humidity in a building. An HVAC system uses a number of different devices to do this. One device is called a humidifier. The humidifier adds moisture to the air. This makes the air less dry. The HVAC system then uses a evaporator to cool the air and remove moisture from it. This leaves the air with less water vapor in it. The HVAC system then use a condenser to warm up the air and add moisture back into it. This increases the level of humidity in the air.
