Winter changes the way air moves through your home. Windows stay closed, heaters run for hours, and indoor air becomes dense with everything from dust to pet dander. Air purifiers work harder this time of year, which means a little seasonal maintenance keeps them performing at their best.

Caring for your device is simple once you understand what winter air does and why filters need more attention now than they do in spring or summer.

 

Why Winter Air Is Tougher on Your Purifier

Cold weather naturally traps air indoors. Heating systems push warm, dry air through vents, stirring up dust that would normally settle. Humidity drops, and dry air carries particles more easily. Because nothing escapes outdoors, everything circulates back through your air purifier. This heavy workload makes winter the most important season for regular cleaning and timely filter checks.

Here are a few reasons winter creates heavier demand on your purifier:

• Indoor air recirculates for months, which increases the amount of dust, pet hair, and dry particles moving through your space.
• Heating systems lift settled debris from floors, vents, and fabrics back into the air.
• Low humidity allows particles to stay suspended longer instead of settling.
• Closed windows reduce natural ventilation, so your purifier becomes the primary source of air movement.
• Holiday cooking, gatherings, and increased indoor activity add even more material to the air.

 

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Focus on the Pre-Filter First

The pre-filter handles the largest particles before the main filter does the fine work. In winter, this layer collects far more dust than usual. Cleaning it every few weeks helps maintain steady airflow and reduces strain on the deeper filters. 

Most models allow you to simply pop the pre-filter out and clean it based on its shape. 

Cylindrical pre-filters should only be vacuumed or wiped down with a damp cloth, while rectangular or square pre-filters can be vacuumed or rinsed under water. Check your pre-filter's shape to determine the appropriate cleaning method, then let it dry completely before putting it back.

A clean pre-filter keeps your purifier quieter, more efficient, and better able to pull air through the system.

 

Check Your Main Filters More Often

The pre-filter is the only washable part of the system. We repeat: do not wash the main filter! In fact, it cannot be reused, either. The main filter should be replaced once the filter indicator turns on. In winter, indoor air often carries more dust and dry particles, which means the main filter may reach the end of its life sooner than usual. 

If your purifier begins running at higher fan speeds or the indicator activates, that is a sign the filter needs to be replaced. A fresh filter helps maintain steady airflow and accurate air quality readings throughout the season.

If you're someone who can never remember to replace your air purifier filter, you aren't alone! Try a filter subscription that does the thinking for you.

 

Keep Airflow Paths Clear

Your air purifier needs room to breathe. Winter creates more dust around vents, baseboards, and floors, so wiping the outside of the purifier and keeping a few inches of space around it helps maintain strong airflow. Dust can collect along the intake and exhaust areas, so a quick wipe every few weeks prevents buildup that affects performance.

If your model uses a particle sensor, keeping that area clean also helps it read air quality correctly.

 

Let It Run Consistently

With homes sealed for months, a purifier only works well when it stays active. Running it regularly keeps dust and particles from settling and reentering the air. 

• Auto Mode is helpful in winter because it adjusts fan levels based on real-time conditions.
• Sleep Mode lets you maintain filtration overnight without loud noise.

Consistency is the key to maintaining cleaner winter air.

 

Quick FAQs

How Often Should I Clean the Pre-Filter in Winter?

Every two to four weeks, depending on dust levels in your home.

Should I Replace My Filter Sooner in Winter?

Possibly! Heavier dust loads can shorten the lifespan of HEPA or Max2 filters. Replace them when the indicator appears.

Can I Wash the Main Filters?

No. Only the pre-filter is washable. The deeper filters must be replaced.

Why Does My Purifier Run More in Cold Weather?

Winter air contains more indoor pollutants and less outdoor exchange, so the purifier increases fan speed to compensate.

 

Keep Your Air Cleaner All Year

Great air starts with the right purifier. Learn more about Coway Airmega models and how they keep your home healthier year-round.