How to keep your humidifier clean

A humidifier can combat a dry heating system to keep your home pleasantly moist in winter. Sadly, moist air isn't all you'll breathe in if you don't keep that machine whistle-clean. Here's how you can clean your humidifier and use it safely.

A dirty machine can spew bacteria and mould into the air that can cause flu-like symptoms, or worse.

• Have you ever heard of "humidifier lung"? It's an inflammation of the lungs (also known as hypersensitivity pneumonitis) caused by breathing fungus-laden air. It'll saddle you with coughing, fever, chills — the works.
• If you don't change the reservoir water, empty the drip pan daily and clean the inside of the water tank frequently, fungi and bacteria will start to grow — as evidenced by those little black dots and the faint layer of scum you see floating in humidifier water that's been neglected too long. Those bugs can hide in internal parts, too, so cleaning them out and disinfecting your humidifier may not be an easy task.
• If you get lazy, the fine mist emanating from your humidifier will carry those little stinkers throughout your room and into your lungs, where they can irritate your respiratory system, worsen asthma, cause an allergic reaction or chronically build up into the dreaded humidifier lung.

To keep your humidifier clean, follow this advice:

• Every three days, unplug the machine, empty the tank and use a brush or scrubber along with a three percent hydrogen peroxide solution to remove any film or scaly deposits. Wipe all surfaces dry. Perform any other steps according to the manufacturer's directions.
• Clean or replace the unit's filter at intervals specified in the directions.
• Refill with distilled water rather than tap water. Tap water often contains minerals that can clog filters, encourage bacteria growth and end up as a fine white powder on your furniture.
• Buy a hygrometer at a hardware store to measure the humidity in your home and don't let it exceed 50 per cent — above that level of humidity, mould can grow quickly in your walls and elsewhere.

Keep these tips in mind and clean your humidifier the right way for the best results.