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The Winix C535 is a sizeable air purifier with some interesting filtration stages and design features. While it is a thorough air purifier, there may be some hidden dealbreakers for you.
To help you with your choice, we have reviewed the features, filtration stages, pros, cons, common concerns, and overall performance review.
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An Energy Star Rated with a large construction
The Winix C535 is a large, rectangular unit with a tall, slim construction. The front-facing panel features a series of small holes through which unpurified air can flow. The digital control panel sits along the top of the unit. While it’s not the most modern or stylish looking air purifier, it is simple and sleek enough to fit in with most home decor styles.

The C353 is an easy air purifier to operate, as the digital control panel is simply set out with clearly-marked buttons and indicator lights. You can also use the remote control to adjust fan speed and mode from a distance.
- Size: 8.2 x 15 x 23.6 inches
- Weight: 15.4 pounds
- Recommended positioning: on the floor
- Covering area: 360 square feet
- Noise: 27.8 – 60 decibels
- Warranty: 2 years
- Energy: 70 watts, Energy Star Rated
The Winix C535 has a CADR (clean air delivery rate) of 243 for dust, 246 for pollen, and 232 for smoke. CADR refers to the volume of air that can be cleaned by the air purifier, measured in cubic feet per minute.
Surprisingly quiet
For a comparatively large unit, the Winix C535 is very quiet on the lower fan speeds (low and medium). The high and turbo speeds are audible but are not excessively loud. For reference, 28 decibels (the lowest fan speed noise level) is roughly the same noise level as a whisper. If you are sensitive to noise at night, you can use the Sleep Mode which switches the fan speed to low.
Notable features
Fan Speeds: There are four fan speeds; low, medium, high, and turbo. You can choose to select fan speeds manually or leave it up to the machine by switching the auto mode on.
Timer: The timer allows you to select 1, 4, and 8-hour increments. For example, you may want the machine to run overnight and switch off in the morning after you leave for work, so you would select the 8-hour option.
Air quality indicator: an LED on the control panel changes color according to the quality of the air at the time. (Blue = good, yellow = fair, and red = bad).
Check filter light: This lights up when the true-HEPA filter is due to be changed. There is also a reset button that needs to be pressed each time the filter is replaced.
Auto mode: When in auto mode, the fan speeds change according to the quality of the air as determined by the air quality sensors.
Sleep mode: when in sleep mode, the fan speed automatically switches to low, and the air quality indicator light switches off. When the unit is in auto mode, sleep mode is automatically applied if low light is detected in the room.
Remote control: allows you to turn the unit on/off, manually change fan speed, and switch to auto mode.

HEPA & PlasmaWave Filtration Systems Review
The Winix C535 is advertised as having a 3-stage filtration system, with true-HEPA filtration. However, there are really 4 stages, including a pre-filter.
Pre-filter: a permanent, washable filter that captures the largest particles. This helps to keep the activated carbon and true-HEPA filters clear as they cannot be washed.
Activated carbon filter: the carbon filter removes odors and chemicals from the air. It helps with smoke, food and pet odors in the home. This filter is different to the AOC filter used in other Winix models, which is washable.
True-HEPA filter: captures 99.97% of particles as small as 0.03 microns, and is, therefore, a true-HEPA filter.
PlasmaWave: this emits negative and positive ions into the air which then combine with water vapor. The result is something called a “hydroxyl”. Hydroxyls seek out pollutants such as gasses and chemicals, destroying them.
The PlasmaWave is described by Winix as releasing “no harmful ozone”. This doesn’t mean there is no ozone at all, it just means that there’s a small amount which falls below the California Air Resources Board’s guidelines for ozone emissions.
Does it help with allergy symptoms and household odors?
Thanks to the true-HEPA filter and pre-filter, the C535 does a great job of reducing allergy symptoms as it can capture the smallest, most irritating allergens. Customers have reported waking up feeling clearer and healthier since using the Winix C535.
The carbon filter refreshes the air and removes odors from pets, food, and smoke. This model is recommended for asthma and allergy sufferers due to the true-HEPA filter and auto mode which increases the fan speed when higher volumes of allergens are detected.
Permanent pre-filter, replaceable HEPA and carbon filters
The cleaning and maintenance requirements are standard for most HEPA air purifiers. Aside from replacing or washing filters, the front panel needs to be wiped with a damp cloth. The interior of the unit should also be vacuumed (ideally with a brush attachment).
Can the filters be washed?

Only the pre-filter can be washed. To keep the pre-filter clean in between washes, use your vacuum cleaner to remove dust and debris. To wash, simply rinse it in warm water and leave to dry completely. The carbon and true-HEPA filters cannot be washed.
How often do the filters need to be replaced?
The carbon filter should be replaced every 3 months, and the true-HEPA filter should be replaced every 12 months. There is an indicator light that tells you when 12 months have passed since the true-HEPA filter was last changed.
Where are replacement filters available, and how much do they cost?
You can find genuine Winix filter replacement packs on Amazon. They include one true-HEPA filter and four carbon filters, enough for one year. The pack’s cost varies in price depending on sales and specials but is reasonably affordable overall for a year’s worth of filter replacements.
How does the Winix C535 compare to the Winix 5500-2?
These two models have the same CADR ratings, recommended room sizes, and almost the same filtration systems. However, the 5500-2 has the AOC carbon filter, while the C535 has a carbon sheet filter. The AOC filter is washable, and lasts for one year, while the carbon sheet filter lasts for 3 months and is not washable. They have the same features in terms of fan speeds, modes, and timer.
Winix C535 Pros & Cons
Pros 👍
✔ True-HEPA filtration
✔ Quiet operation
✔ Helps to relieve and reduce allergy symptoms
✔ Auto mode and sleep mode for low-maintenance operation
Cons 👎
✘ Lights cannot be turned off completely
✘ May produce trace amounts of ozone
Our Review Verdict
The Winix C535 Air Cleaner is a good choice for people who suffer from asthma and allergies and require a true-HEPA filter for the cleanest air. The filter maintenance requirements are made simple by the one-year filter replacement package available on Amazon.
If you require a quiet, intelligent and effective air purifier that can monitor your air quality, put the Winix C535 at the top of your list.
Frequently Asked Questions
Because of the PlasmaWave, there may be very small amounts of ozone produced. However, the unit is approved by the California Air Resources Board as being well within the ozone safety parameters, so there is nothing to worry about. However, the PlasmaWave feature can be switched off if you are concerned about ozone.
For best results, yes. The unit has an Energy Star of approval, so it won’t overload your power bill if you choose to leave the unit on at all times. Just remember to check the filters regularly to ensure the best results.
No, the lights on the control panel remain on at all times. The air quality indicator light is switched off when sleep mode is activated.
Winix C535 Air Cleaner Use Tips
- When finding replacement filters, always opt for genuine Winix filters. The pack that is compatible with the Winix C535 is the Filter A 115115 pack.
- Remember to press the reset button after you have replaced your true-HEPA filter. You’ll need a small object such as a pin to do this.
Continue Shopping Winix C535 at Amazon (Opens in a new tab)
- An Energy Star Rated with a large construction
- Surprisingly quiet
- Notable features
- HEPA & PlasmaWave Filtration Systems Review
- Does it help with allergy symptoms and household odors?
- Permanent pre-filter, replaceable HEPA and carbon filters
- How does the Winix C535 compare to the Winix 5500-2?
- Our Review Verdict
- Frequently Asked Questions
- Winix C535 Air Cleaner Use Tips