What Does a CPAP Humidifier do?

CPAP humidifier
water reservoir for CPAP humidifier – DeVilbiss SleepCude

If you find yourself waking up with a dry mouth, nose or throat, then a humidifier should instantly solve that problem and others. By adding moisture to the air provided by your CPAP machine, it helps to keep your mouth from drying out throughout the night. Similarly, if you find the air from your CPAP to be cold and uncomfortable, a humidifier adds warmth to the moist air, and this should make your therapy more comfortable.

It is clinically proven, through several studies, that humidification improves compliance and helps CPAP and BiPAP users avoid suffering from a dry nose, mouth and throat. A humidifier can be extremely beneficial for those who are often visiting countries with drier climates. Still, even in the UK and colder parts of Europe, CPAP users report significant benefits from a humidifier added to their setup.

For sufferers who are mouth breathers who need a full-face or oral mask, heated humidification is a must-have feature.

If you do breathe through your mouth, you probably will need a full mask, and this increases the chance you will need a humidifier. When you breathe through your nose, the hairs in the nasal airway conditioning the air with heat and humidity before it enters the lungs. When you breathe through your mouth, this process is not present and can lead to uncomfortable dryness. One other note is that allergies and illness can make the effects worse.

Intus healthcare advice:

All though we do believe that humidifiers can improve the comfort of the CPAP therapy for suffers, we would advise that if you’re new to CPAP therapy, you should try your mask and machine before you purchase a humidifier.


Everything you need to know about humidification

A CPAP Heated Humidifier houses a water chamber, which it heats to add moisture to the air provided by your machine. They are ideal for those who find the device leaves them waking with a dry mouth, sore nasal passages or find the air cold and therefore uncomfortable.

They are usually an additional piece of equipment that locks onto or into your main CPAP machine, but some CPAP machines come with a humidifier built-in. Most CPAP machines will have their specific humidifier available.

For some people, having a humidifier moisten and warm the air from their CPAP machine is an essential part of their therapy; for others, there is a little benefit so it can come down to personal preference. Those using a full face mask are more likely to require humidified air as they are more susceptible to a dry mouth. For those using an oral mask, humidified air is more or less essential.


I’m not sure I need a humidifier?

For most CPAP machines, humidifiers can be purchased at a later date and integrated separately, so you can order your CPAP machine without the humidifier and see how you go. However, if you do find yourself already waking up with a dry mouth before you’ve started CPAP therapy and are new to CPAP therapy, then CPAP is likely to make this condition worse, and we would recommend purchasing one immediately.

If you know you need a humidifier, then it could be worth considering a machine with a humidifier built-in. An example of this is the Fisher and Paykel ICON. This design adds greater convenience, and they’re often more compact than having two separate units (space on your bedside table).

Intus healthcare advice:

  • CPAP machines with built-in humidifiers can be delicate and require extra care in transit. Therefore it is advised the humidifier is entirely free of water – and preferably packed separately if you are travelling with your CPAP machine.
  • If you are running your CPAP machine from a 12V source (for example in a car or caravan), then your humidifier will not be able to run off of DC power. It can still be used passively (unpowered and unheated).
  • Overall, if you will be travelling, we would always advise you to leave the humidifier behind unless it is essential or you are away for an extended period.
  • If you are going to be travelling, we would recommend purchasing a CPAP machine that has a separate humidifier rather than one that is built-in.

Problems with humidified air from your CPAP humidifier

A possible drawback of humidified air is from, what we call Rainout, the proper name for condensation build up in the tubing and mask. It is likely to happen because the tubing and CPAP mask will be at room temperature (20–22 °C (68–72 °F)), causing the warmer air from the CPAP machine to cool and condense as a result. Rainout can result in a gargling noise or just general discomfort; it is particularly common in the winter months.


There are ways to counteract Rainout (condensation buildup)

One solution we offer is a hose fleece, which provides the CPAP machine’s hose with insulation (it can also make the tubing physically more comfortable to touch). Our second and more comprehensive option is to use a heated CPAP hose, such as the Hybernate Heated Breathing Tube. The heated hose ensures the temperature difference inside the tubing is negligible, preventing Rainout and ensuring the air reaches you at the correct temperature.