What is the purpose of using a humidifier with a therapy device?

Humidifiers are designed to moisturise the air that is being delivered to you from the therapy device. There are two types of humidifiers—heated and unheated. Heated humidifiers do not “heat the air” but will increase the moisture content of the air delivered. Humidifiers can help to reduce some of the side-effects of therapy, such as dry nose.