Combining the CPAP hose fleece with your tube insulates your heated air for more comfortable treatment.
Is CPAP Rainout Dangerous? Causes and Solutions
Fact Checked
Intus Healthcare’s writers, customer service team, and sleep experts review and ensure this information is accurate.
No, CPAP rainout is not directly dangerous, but it can impact your CPAP therapy and affect the quality of your sleep.
Rainout is a common problem but can be easily identified and solved with our quick tips below.
Table of Contents
What is CPAP Rainout?
Rainout occurs when the heated airflow from your humidifier cools as it travels through the tubing, leading to condensation buildup.
This often happens when a humidifier is combined with an unheated tube. As the air flows through the unheated tube, it condenses and creates water droplets in the tube that run through your mask.
This condensation buildup within your tube and mask can cause discomfort, mask leaks, and disrupt sleep.
Humidification is an essential comfort feature for many CPAP users, helping to prevent congestion, a dry mouth, nose and throat irritation (1).
Congestion is one of the most common side effects of CPAP therapy, therefore humidification can be crucial to maintain comfort and improve therapy. Research found that 67% of CPAP users experienced nasal congestion (2).
Learn More:
10 Common CPAP Side Effects and How to Resolve Them
How to Sleep Better with a Blocked Nose: 30 Remedies
How to Identify CPAP Rainout
Here are some signs of condensation buildup within your equipment:
- You hear a gurgling sound from your machine.
- You wake up coughing or choking from inhaling water from your mask.
- You can hear or see water within your tube when you shake it.
- When you remove your mask, you feel moisture on your face or under your mask.
10 Effective Solutions to Stop CPAP Rainout
Easily overcome rainout without compromising your therapy with these simple tips:
- Use a hose fleece or heated tube to insulate your tubing and keep the temperature consistent as it travels from your humidifier to your mask. Most brands offer machine-specific heated tubes to work alongside your device. Another way to provide more insulation to your tube is by covering it with a blanket.
Hose Fleece
Universal Heated Tube
The Universal Hybernite Heated Tube pairs with any machine and humidifier unit to keep the airflow warm.
- Place your CPAP machine on a flat, stable surface lower than your bed. This positioning helps prevent water from flowing back into the machine.
- Avoid overfilling the humidifier chamber; only fill to the maximum fill line.
- Always empty the humidifier chamber before moving the CPAP machine to a new location to avoid accidental spillage.
- Ensure your room temperature is not too cold, which can cause humidified air to cool faster.
- After cleaning, allow the humidifier chamber, tube, and other components to dry completely before reassembly.
- Adjust your humidifier settings by reducing the humidity level to reduce excess moisture. You can adjust the humidity setting in one-level increments to find the optimal level for your comfort.
- Regularly inspect your humidifier, check that it seals correctly, and there are no signs of damage or wear. This will help maintain the quality of your therapy.
- Ensure the humidifier chamber is closed correctly and locked before using the machine, to prevent leaks and rainout.
- Consider a device with automatic features to continuously monitor and adjust your mask and tube air temperature and humidity for optimal treatment experience. An example of this is ResMed’s AirSense collection featuring Climate Control.
ResMed AirSense 10 CPAP Machine Bundle
The AirSense 10 bundle includes a humidifier and heated tube to offer you the best results from your treatment.
ResMed AirSense 11 CPAP Machine
The AirSense 11 can be combined with the compatible humidifier and heated tube for enhanced CPAP therapy.
These steps improve your comfort and compliance and help extend your CPAP machine’s lifespan (3). Many of our customers experience rainout, if the tips above don’t solve your problem, please contact us so we can further support you.
How to Prevent CPAP Rainout when Using a Heated Hose
Experiencing rainout when using a heated tube is uncommon; however, should you experience it, there are a few solutions:
- Adjust your humidifier settings if your humidifier temperature differs significantly from your room temperature. For example, your settings may need to be higher if you live in a very hot climate. Alternatively, if your humidifier temperature is set too high in a cooler room, this can lead to rainout.
- Adjust your bedroom temperature to help maintain a stable ambient temperature in the room.
Maintaining Hygiene: How to Remove Water in Your CPAP Equipment
Removing the water build-up is essential as it can cause germs, bacteria, and fungus in your equipment. Inhaling airflow from a dirty tube, mask or water chamber can make you unwell and decrease the lifespan of your CPAP supplies.
Regularly cleaning all parts of your equipment helps to reduce bacteria and ensure your treatment remains sanitary. Please follow your manufacturer’s guidance when cleaning each part of your equipment.
Here’s how you can safely remove condensation:
- Begin by disconnecting your tube from your machine and mask, rinsing it thoroughly with warm water and allowing it to air dry.
Ways to dry out your tube:
- Allow the tube to air dry completely on a clean surface after cleaning.
- Hang the tube over a shower rail or a doorway, to help drain any remaining moisture and speed up drying.
FAQs
What should I do if I can’t stop rainout?
If you have tried the above recommendations and are still experiencing condensation, please contact your healthcare provider or sleep clinician for advice.
You can always contact us for support; we are experts on all things Sleep Apnoea and have helped over 250,000 people with their sleep.
Does rainout affect my CPAP therapy?
Yes, excess moisture can affect your treatment comfort and effectiveness. Water buildup in your tubing can also increase bacterial growth and the risk of infection. This can also impact the lifespan of your machine.
How do I know if my heated CPAP tube is working properly?
When your heated tube is connected and your machine is on, you should feel warm air coming from the tube.
If the air is cold, it indicates that the tube isn’t heating properly, and you may need to consult your healthcare provider or check your humidifier settings and tubing connection.
Related articles:
All you need to know about CPAP humidification
CPAP Aerophagia: Causes, Symptoms and Solutions
Should you use distilled water in your humidifier?
Summary
Rainout is a common inconvenience caused by the cold and warm interaction that interferes with your CPAP therapy.
It should not prevent you from using your CPAP humidifier, as it is quickly fixed by following our expert tips.
Overall, the benefits of using humidification outweigh the potential risk of rainout, especially since there are steps to take to prevent it.
Research has found that patients using a heated humidifier had fewer upper respiratory infections than those who did not (4).
Explore our range of heated tubes and humidifiers or contact our experts for tailored advice.
About Our Editorial Team
Written By,
Danielle Mahri, Staff Writer
Danni is a degree-educated content writer who works closely with our clinical and customer services teams to ensure every article is well-researched and accurate. Each article is written to educate, help, and advise on Sleep Apnoea, spread awareness, and encourage treatment.
Medically Reviewed By,
Jay Gadher, Clinical Manager
Jay is an experienced Respiratory and Sleep Clinical Scientist. He completed his BSc in Healthcare Science, which has allowed him to gain expertise in scoring sleep studies. His knowledge and insights about sleep science and human health ensure every article reflects the latest data.
References
- Massie CA, Hart RW, Peralez K, Richards GN. (1999). Effects of humidification on nasal symptoms and compliance in sleep apnea patients using continuous positive airway pressure. Available at: https://pubmed.ncbi.nlm.nih.gov/10453869/. Accessed: 23.01.2025.
- Bajaj, P. (2012). Does Presence of Nasal Congestion Influence Patient’s Choice of Delivery Interface for Continuous Positive Airway Pressure Therapy? Available at: https://www.jacionline.org/article/S0091-6749(11)02513-9/fulltext. Accessed: 23.01.2025.
- Lance CG. (2019). Positive airway pressure: Making an impact on sleep apnea. Cleve Clin J Med. Available at: https://pubmed.ncbi.nlm.nih.gov/31509501/. Accessed: 23.01.2025.
- Bernd M. Sanner, Nicole Fluerenbrock, Anja Kleiber-Imbeck, Jochen B. Mueller, Walter Zidek. (2001). Effect of Continuous Positive Airway Pressure Therapy on Infectious Complications in Patients with Obstructive Sleep Apnea Syndrome. Available: https://karger.com/res/article-abstract/68/5/483/288414/Effect-of-Continuous-Positive-Airway-Pressure?redirectedFrom=fulltext. Accessed: 23.01.2025.