The Winix C545 is a mid-range air purifier. It shares some aspects in common with the newer and pricier Winix 5500-2 and even has the unique advantage of Wi-Fi connectivity, allowing you to monitor air quality and filter lifespan while you're away from home or even adjust the device's settings. That said, it does have a smaller HEPA filter and a sheet-type carbon filter instead of the pellet-type one found in the 5500-2, which has a larger effective surface area.
Our Verdict
The Winix C545 air purifier is good for pet owners. It isn't necessarily the best for capturing small airborne particles like pet dander, but it's also far from terrible in this regard. Its clean air delivery rate is somewhat impressive for a relatively compact device. It also runs quietly at lower fan speeds, so it won't startle any animals that are particularly sensitive to loud noises, though it will get louder when you crank up the fan.
- Good clean air delivery rate.
- Companion app allows for remote operation and scheduling.
- Has a sheet-type carbon filter rather than a more effective pellet-type.
The Winix C545 is a great option for use in bedrooms. It runs very quietly in its 'Sleep' mode, which is great if you leave it running overnight. You can set up operating schedules through the companion app, so if you'd rather not have it run at all while you're sleeping, you won't have to manually turn it off before going to bed. Its air purification performance is also good, though not quite class-leading.
- Good clean air delivery rate.
- Companion app allows for remote operation and scheduling.
- Very quiet in 'Sleep' mode.
- Has a sheet-type carbon filter rather than a more effective pellet-type.
- Good clean air delivery rate.
- Companion app allows for remote operation and scheduling.
- Has a sheet-type carbon filter rather than a more effective pellet-type.
- Good clean air delivery rate.
- Companion app allows for remote operation and scheduling.
- Has a sheet-type carbon filter rather than a more effective pellet-type.
Performance Usages
Changelog
- Updated Nov 04, 2025: Version 1.0.2 of our Air Purifier Test Bench rectifies calculation errors in our existing Particle Filtration Rate test to provide more representative results of some units. For a more detailed breakdown of the changes made, see our full changelog.
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Updated Oct 01, 2025:
We've corrected an error in the 'Activated Carbon' field in the Filter Configuration box and changed the result to 'Sheet.'
- Updated Oct 31, 2024: Converted to Test Bench 1.0.1.
- Updated May 14, 2024: Review published.
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Differences Between Sizes And Variants
The Winix C545 is available only in one color variant: 'White.'
If you encounter another variant of this device, let us know in the comments, and we'll update our review.
Popular Air Purifier Comparisons
The Winix C545 is a mid-range air purifier with Wi-Fi connectivity. It offers good, but not necessarily superb, air purification performance; the pricier Winix 5500-2 uses a larger HEPA filter and a more effective pellet-type odor-absorbing carbon filter, though the 5500-2 also isn't Wi-Fi enabled.
The Winix 5500-2 is better than the Winix C545. Both models have air quality sensors that allow them to automatically adjust their fan speed depending on real-time particle levels. That said, the 5500-2 has a higher clean air delivery rate and better fine particle filtration performance, all while occupying a similar footprint. Meanwhile, only the C545 is Wi-Fi enabled, which allows you to remotely operate it from afar.
Test Results
The 'Air Quality' LED indicator changes color based on current air quality:
- Blue: Good
- Orange: Fair
- Red: Poor
Engaging the 'Sleep Mode' will turn off all the lights, except for the actual 'Sleep Mode' button and the 'PlasmaWave' indicator light if you've left the ionizer on.
The C545 is compatible with the Winix Smart app, which allows you to adjust device settings and monitor the current air quality. You can also set schedules, allowing you to set when the device will run throughout your week and choose specific settings, like when you want the ionizer to run (if at all). It's worth noting that this air purifier can only connect to 2.4 GHz Wi-Fi networks.
This device uses a 'four-stage' filtration system similar to the Winix 5500-2. Like that model, this filter system comprises three physical stages and a particle ionizer. There's a mesh pre-filter for trapping larger particles, a HEPA filter, and a carbon filter for minimizing odors and VOCs. However, like most consumer-grade air purifiers, the amount of activated carbon is small and won't really have much of an impact on high VOC levels. That said, its filter system is a little more rudimentary, with a smaller HEPA filter and an activated carbon sheet filter instead of the pellet type found in the 5500-2, which yields a larger effective surface area. The C545's ionizer imparts a negative charge on fine particles. It causes them to clump together and fall to the ground, though this process does release ozone as a byproduct, a respiratory irritant. As per the manufacturer, the amount of ozone released from the device's 'PlasmaWave' ionizer is nominal and won't surpass the safe concentration of 0.05 ppm. If you don't want to use the ionizer, you can turn it off. In testing, we observed a drop in 0.3 µm particle concentration with the ionizer turned on, but it had very little impact on the device's air cleaning rate.
You'll need to vacuum off any stuck-on debris from the pre-filter every 14 days. If it's especially soiled, you can rinse it under room temperature water, but make sure not to use any detergent or soap and to let it dry for at least 24 hours before reinstalling it. It isn't intended to be replaced.
The True HEPA and activated carbon filters aren't washable. The HEPA filter has a lifespan of a year, while the carbon filter needs to be replaced every three months. A replenishment pack contains a single HEPA and four carbon filters and can be purchased here.
We measured the results above with the ionizer turned off to generate data comparable to air purifiers without an ionizer. In extended testing with the somewhat similarly designed Winix 5500-2, we tested air purification performance with and without the ionizer turned on. We found that it had little significant impact on the device's overall performance.