Why do you need humidification during therapy?

When you breathe normally, your nose and upper airway add heat and moisture to the air. By the time it reaches your lungs, air should be at body temperature (37°C or 99°F) with 100% relative humidity (44 mg/L). During therapy, higher air pressure can overwhelm your upper airway’s ability to heat and humidify the air. Colder, dryer air can cause a sore throat, dry nose, mouth or throat, nasal congestion, and a runny nose. 30 - 70% of patients experience these symptoms.

The H5i comes with a water chamber.