What is Rainout and What Causes It?
CPAP rainout happens when humidity reaches an unheated tube and the temperature difference creates condensation. Then, small droplets of water form and splash against your face causing you to wake up.
Picture what happens to an old window in a warm room on a cold day or a chilled can of pop out in the sun on a hot day—similarly, tiny beads of water build up in your CPAP tube and trickle down the mask to your face.
Rainout is essentially caused by heated air cooling inside your CPAP hose. The warmer the humidifier air or the colder your bedroom, the more condensation is likely to occur. If you have the humidifier set to the highest setting, CPAP rainout is almost guaranteed. Luckily, there are several things you can do to avoid or minimize CPAP rainout.
Solutions for Rainout
Sleep disruptions from CPAP tubing gurgling or CPAP machine rainout can cause you to feel tired the next day, even if you were in bed for a full eight hours. With sleep apnea, it’s important to set yourself up to get the best sleep possible—and that includes preventing rainout.
Here are six impactful things you can try for a more peaceful night:
Use Heated CPAP Tubing
Made to manage humidification in real-time based on the ambient temperature levels of your bedroom, heated tubing helps reduce CPAP rainout by keeping the temperature of the air consistent as it travels from the humidifier to your mask. Some machine have heated tubing options for their equipment, like the ClimateLineAir Heated Tube (RESMED AirSense 10, AirCurve 10, Deckmount VT300 etc)
Adjust the Ambient (room) Temperature
If the room is extra cold at night, you’re more likely to experience condensation in your tubing. This is a quick and simple fix, but many people enjoy sleeping in cooler rooms so you may want to adjust the humidifier settings instead.
Adjust Humidifier Settings
The right CPAP humidifier settings can make all the difference. As with different seasons/weather conditions ambient temperature and humidity changes.
Get Machines with Automated Adjustments
CPAP machines from ResMed (AirSense 10 Autoset) has special climate control feature that constantly monitors the temperature of the air in your mask and how it is affected by ambient temperature. As needed, it simultaneously adjusts the humidifier and tubing levels, providing an optimal temperature that helps prevent CPAP rainout.
Move Your CPAP Machine
Make gravity work for you! Place your CPAP machine at a lower level than your mask so condensation can’t flow to your mask while you sleep. If your CPAP equipment is currently on your nightstand, try moving it to a lower shelf or even the floor. Any water droplets that do form will flow back into the humidifier instead of sprinkling across your face.