How to Stop CPAP Rainout: Keep Your Mask and Hose Dry Overnight

Waking up with a wet CPAP mask or hose? You’re not alone. CPAP rainout—when unwanted moisture builds up inside your tubing and mask—can be a frustrating interruption to an otherwise good night’s sleep.

At Easy CPAP, we know just how annoying this can be for sleep apnoea users. That’s why we’ve put together simple, effective tips to help you prevent rainout and enjoy a more comfortable and restful therapy experience.

What Is CPAP Rainout and Why Does It Happen?

CPAP rainout happens when the warm, humidified air from your CPAP machine cools inside the hose or mask and turns into water droplets—just like when your glasses fog up moving from a warm indoor space into the cold.

This can be caused by:

• Cool room temperatures
• High humidity settings on your CPAP
• A cold bedroom overnight
• Using non-heated tubing or an uninsulated hose

Understanding these factors is the first step in preventing excess moisture from messing with your sleep therapy.

How Room Temperature Affects Rainout

Your bedroom temperature plays a key role in whether or not condensation forms inside your equipment. If your room is too cool, the warm air passing through your tube cools quickly, creating water inside the hose or mask.

Keep your sleeping environment at a moderate, consistent temperature to reduce the likelihood of condensation. A comfortable room not only improves your sleep but also keeps your CPAP gear dry.

Finding the Sweet Spot With Your CPAP Humidifier

Most CPAP users rely on humidification to prevent dryness and discomfort—but too much humidity can cause rainout.

Try adjusting your humidifier settings gradually to find the right balance for your room. You want enough moisture for comfort, without causing excess water to form. Heated humidifiers paired with heated hoses are especially good at reducing rainout.

Top Tips to Prevent CPAP Rainout

You can make a big difference with just a few practical steps:

1. Use Hose Insulation or Heated Tubing

   A snug hose wrap or heated tube helps keep the air warm all the way through, reducing condensation.

Heated tube for machines can be found below:

ResMed

Fisher&Paykel

BMC

Philips

Hose wraps can be found below:

https://easycpap.com.au/products/resmed-standard-tubing-wrap

https://easycpap.com.au/products/resmed-slimline-tubing-wrap

2. Keep an Eye on Room Humidity

If your room is too humid, consider using a dehumidifier. Too dry? A small humidifier can help balance it out.

3.Adjust Humidifier Settings

Lowering the humidity level just slightly might be enough to keep your CPAP hose dry.  Refer to your machine humidifer manual to adjust your settings

4. Clean and Maintain Your Gear Regularly

Keeping your mask and tubing clean ensures optimal airflow and performance, reducing any build-up of moisture.

Keeping your CPAP dry isn’t just about comfort—it’s essential for effective sleep apnoea treatment. By understanding what causes rainout and using these simple techniques, you’re well on your way to a peaceful, uninterrupted night’s rest.