The continuous positive airway pressure (CPAP) machine often includes a heated humidifier system to enhance comfort during sleep therapy. This component adds moisture to the pressurized air, preventing common side effects like nasal dryness, irritation, and congestion. Maintaining the humidifier by using the correct type of water and changing it regularly is important for the machine’s lifespan and the user’s health.
The Standard Daily Water Change Schedule
The water reservoir in your CPAP humidifier should be emptied and refilled with fresh water every day. This daily practice is necessary even if you did not use all the water during the previous night’s therapy session. Leaving stagnant water in the chamber creates an environment where biological contaminants can begin to grow.
To maintain the recommended schedule, each morning you should detach the reservoir from the main unit and pour out any remaining water. Following this, the tank should be rinsed with clean water and allowed to air dry completely before the next use. If you are traveling and need to use an alternative water source temporarily, you must return to the daily water change and cleaning procedure as soon as possible.
This daily procedure prevents the build-up of residue and the colonization of microorganisms. Discarding unused water is necessary for maintaining a hygienic therapy system. Manufacturers recommend this daily routine to protect the user’s respiratory health and the integrity of the equipment.
Why Distilled Water is Required
Manufacturers advise using only distilled water because it is free of the minerals found in common tap or bottled water sources. Tap water contains dissolved solids such as calcium, magnesium, and iron, often referred to as hard water minerals.
When the CPAP humidifier heats water, the pure water turns into vapor, but these heavy minerals are left behind. Over time, these mineral deposits precipitate out of the water and accumulate on the heating plate and the walls of the water reservoir. This accumulation is known as scale or limescale and appears as a white, crusty residue.
This mineral buildup reduces the efficiency of the heating element, forcing the machine to work harder to achieve the desired humidity level. Scale can also damage the machine’s components, shorten the lifespan of the water chamber, and potentially void the manufacturer’s warranty. Using distilled water eliminates this chemical risk, ensuring the machine maintains optimal performance and longevity.
Preventing Mold and Bacterial Growth
The primary health risk associated with improper water maintenance is the potential for biological contamination inside the warm, moist environment of the humidifier. Even distilled water, which is initially free of microbes, can become a breeding ground for bacteria, mold, and fungi if left standing for more than 24 hours.
When a CPAP machine is used, the air is pushed through this water, and any contaminants present can be aerosolized. These airborne spores and bacteria are then delivered directly into the user’s airway, posing a significant risk of respiratory irritation, sinus infections, or allergic reactions. The presence of organic matter, such as skin cells or dust that enters the machine, further encourages the development of this microbial growth.
Regularly emptying the water tank is a preventative measure against the formation of biofilms, which are communities of microorganisms that adhere to surfaces. Complementing the daily water change with a weekly washing of the reservoir using mild soap helps disrupt and remove these potential contaminants. This combined routine ensures that the air being delivered for therapy is clean and safe to breathe.