Winix C535 (Winix Zero) Air Purifier – Hands-on Review

Full Review

Winix is a well-known company that has been in the market for many years. They produce air purifiers for all room sizes. The Winix C535 (also known as the Winix Zero) has gained tremendous popularity primarily because of its features offered at an affordable price. So far, I have tested several models from Winix.

The design and advanced options of the Winix C535 are very similar to the Winix 5500-2 model. It’s intended for rooms up to 360 sq. ft. (33 m²). It uses four-stage filtration technology, including an ionizer that can be turned on or off.

We tested the Winix C535 in various conditions and rooms. In this review, you will find out how good it is, whether it justifies its popularity, and if it’s worth buying.

How We Tested the Winix C535?

1. For the filter efficiency testing, we used the Temtop LKC-1000S laser particle meter, which measures PM2.5 (µg/m3), PM10 (µg/m3), Particles (per/L), and HCHO (mg/m3) in the air, and also calculates the AQI.

2. We placed the Winix C535 in a 320 sq. ft. (30 m²) room. Then, we recorded the initial air quality values using the Temtop laser particle meter and let the Winix C535 run at maximum speed.

3. After 60 minutes, we measured the new values using the Temtop laser particle meter and saved the data.

4. Next, we placed the Winix C535 in a glass box, which we then filled with smoke. Then, we measured how much time was needed for the air purifier to remove all the smoke from the box.

5. Using a special noise measurement tool, we tested the air purifier’s noise level at all speeds. We measured the noise level on the dBA scale.

6. Finally, we measured the power usage at all speeds using an energy meter, after which we calculated how much it would cost to use the device at a particular fan speed for one month. For reference, we used an energy price of $0.12 per kWh.

We tested the Winix C535 in various rooms with different conditions and sizes.

Regarding performance, my biggest complaint is about the auto mode. It works well in gas-polluted environments (cooking odors, VOCs, cigarette smoke, etc.), but it could be improved to detect dust particles, which would enhance auto mode’s overall effectiveness.

On the other hand, the auto mode feature has made using the Winix C535 much easier, at least in odor-polluted environments.

I want to mention that we didn’t use PlasmaWave in our tests for two reasons: it doesn’t significantly improve air quality, and this technology produces ozone as a byproduct.

Testing in a 320 sq. ft. (30 m²) Room

In the first test, conducted in a 320 sq. ft. (30 m²) room, the Winix C535 achieved outstanding results. It reduced the number of PM2.5 particulate matter from 80.7 to 4.1 µg/m³, an air quality improvement of about 95%.

The device operated at maximum speed throughout the 60-minute test.

Compared to other competitive air purifiers tested in the same room, the Winix C535 ranks among the top performers. As shown in the chart below, its main competitors, such as the Coway AP-1512HH, Winix 5500-2, and Levoit Core 400S, improved the air quality by 96%.

Overall, I’m truly satisfied with the Winix C535’s performance and believe it would be a great option for combating common pollutants in your home.

Testing in a 320 sq. ft. (30 m²) Room – Auto Mode

We tested the Winix C535 in the same room under identical conditions, but this time with the auto mode on.

The auto mode on this model isn’t always the best solution because the smart sensor only detects odors. However, the Winix C535 did a great job in this test, improving the air quality by about 90% in just 60 minutes while working at maximum speed.

It lowered the PM2.5 particulate matter from 63.8 to 6.4 µg/m³.

I would use the Winix C535 on auto mode only if my environment is polluted by wildfire smoke, cooking odors, cigarette smoke, or similar pollutants.

Performance – Smoke Removal Test

We placed the Winix C535 in our unique smoke test and measured the time it took to remove all the smoke from a glass box.

The Winix C535 worked at maximum speed throughout the test and managed to remove all the smoke from the box in just 21 seconds.

As you can see in the chart above, the Winix C535 is the slowest air purifier in this test, but to be fair, it was compared to some of the best air purifiers on the market.

For example, the Levoit Vital 200S removed all the smoke in 15 seconds, and the giant Blueair 211+ did so in just 9 seconds.

Overall, removing all the smoke in 21 seconds is a fantastic result, and the Winix C535 confirmed its excellent performance.

The Winix C545 uses five fan speeds, including sleep mode and four different speeds.

It’s generally quiet, especially at the lowest speed, where it produces a sound level of 40.8 dBA. At the maximum speed (turbo mode), the situation is quite different, as it produces a sound level of 63.2 dBA.

When compared with competitive air purifiers, it’s generally much quieter, especially at the lowest speed. The only quieter air purifier at the lowest speed is the Winix 5500-2, which produces 40.6 dBA.

However, at maximum speed, there are much quieter devices. For example, the Blueair 211+, which is several times more powerful than the Winix C545, produces a sound level of only 59.7 dBA at maximum speed.\

Below is a table listing the noise levels at all speeds so you can see how loud this air purifier is overall.

In conclusion, it’s not the best choice for bedroom use, but it is ideal for living rooms, kitchens, offices, and similar spaces.

The Winix C535 is a large power consumer. It uses a motor of 70W, which puts it among the largest power consumers in its category.

Interestingly, it consumes only 3W in sleep mode and about 6W at the first speed.

At the maximum speed, it consumes 54.1W. So, if you were to use this air purifier at maximum speed, 24 hours a day, for one month, your electric bill would increase by about $4.74.

When compared to similar air purifiers, the Winix C535 is among the largest power consumers. For example, the Levoit Core 400S would cost you about $3.07 under the same conditions.

In addition to the electricity cost, there is also the filter replacement cost, which is slightly higher for the Winix C535. The only advantage here is that you have to replace the filter only once per year.

Therefore, if we consider the replacement filter’s price and the annual electricity consumption, the C535 air purifier’s maintenance will cost you almost as much as the device itself.

Filtration Technology

The Winix C535 uses four-stage filtration. The first filtration stage is a washable pre-filter, the second is the carbon filter, the third is the True HEPA filter, while the last filtration stage is PlasmaWave.

Besides, there is a pre-filter that removes large particles. All filters used in the C535 are not washable except the pre-filter.

Pre-Filter

The air first goes through the Winix C535 pre-filter. This stage is the first line of defense against the most extensive airborne particles found indoors.

The pre-filter is washable and should be cleaned on average every 14 days. Pre-filter will protect other filters, extend their lives, and make the whole machine work better.

Carbon Filter

The carbon filter is not made up of carbon pellets. The carbon filter in the Winix C535 is a fibrous filter coated with carbon. Carbon filters reduce VOCs and household odors from cooking, pets, and smoke.

This type of carbon filtration is common in many air purifiers. For example, Coway Mighty uses a fibrous carbon filter. The Winix 5300-2 and Winix P300, which are also popular models from the Winix company, use an identical filter for gas filtration.

True HEPA filter

The true HEPA filter captures 99.97% of airborne particles, including pollen, mold spores, dust, pet dander, microbes, and smoke. Almost all the particles that are as small as 0.3 microns in size.

A true HEPA filter is not washable, and under no circumstances should it be washed or cleaned in any other way.

PlasmaWave

I don’t particularly appreciate that PlasmaWave turns on every time the device starts. I think it would be more practical to leave this option off and let users decide to use it. However, the PlasmaWave can be turned off at any time.

How does PlasmaWave technology work?

The PlasmaWave technology creates a low electrical discharge to produce dual polarity ions ( + hydrogen (H+) and – oxygen ions (-O2)) from air moisture. The ions connect themselves to air pollutants’ surface to form Hydroxyls by removing hydrogen from the air structure. This synergy eliminates air pollutants and allows the ions to use the absent Hydrogen ion, removed from the air pollutants’ structure to return as air moisture (H2O).

How to Replace the Winix C535 Filter?

Always use Winix genuine replacement filters for the best performance.

Total time: 10 minutes.

Design

The build quality of the Winix C535 model is top-notch. The Winix C535 is white, except for the control panel on top of the device, which is black.

The device is bulky. The edges are straight. It looks a bit old-fashioned.

The color and appearance can fit into many rooms, such as the bedroom, living room, kitchen, etc. The device is easily transported thanks to the handle located on the top of the device. At the top of the device is the control panel with all the buttons, indicators, and sensors. I will say more about the control panel later in the following Winix C535 review. One thing that I need to mention is the power cord; its length is standard.

Control Panel – Initial Operations

There are buttons on the control panel for complete device control. Besides, there are all the necessary indicators and sensors that the Winix C535 has. The buttons are standard press buttons; they don’t respond on touch. They react to smooth pressure.

The buttons do not light up. However, you will hear a beep sound at each press. The control panel buttons are the on or off switch, the select mode button, the PlasmaWave technology on or off button, the fan speed button, and the timer button.

In addition to the buttons, there are indicators above each button.

When the Winix C535 is facing you, on the left side, next to the edge of the device, is a filter reset indicator as well as light and odor sensors.

Airflow

Air enters on the front of the device, through the cover, and from the sides. After that, the air is filtered through a pre-filter, then through a carbon filter, and finally through a true HEPA filter. If PlasmaWave is on, the air will be additionally filtered. The filtered air comes out on the top of the device and is directed upwards.

Size and Dimensions

The air purifier weighs 14.7 lb. Although a little heavier than average air purifiers on the market, the C535 is easily transported from location to location thanks to the carrying handle. The dimensions of the device are 15 x 8.2 x 23.6 inches.

What’s in the box?

When you buy the device, you get 1x Winix C535, 1x True HEPA filter, 4x Carbon Filter, 1x Remote Control (with battery included), 1x User Manual, and 1x Warranty Card.

Features Overview

Auto Mode

This mode regulates the speed of the device based on air pollution in the room. If the air quality is low, auto mode will automatically switch the fan speed to turbo mode, and vice versa if the air quality is good. In addition to the smart sensor, auto mode is also affected by the light sensor. This means that if the room is dark and the device is operating in auto mode, the C535 will automatically switch to sleep mode.

I used the Winix C535 for a while in the bedroom, and I can say that I was delighted, mainly because of auto mode. Because literally all I need to do is turn on the device, and I can comfortably forget about it. Besides, the remote controller was always at hand, so I could turn it off whenever I wanted. In the evening, when I go to sleep, auto mode on the C535 automatically switches to sleep mode, so I didn’t even notice it, and the air quality in the room was always exceptional.

PlasmaWave

This advanced technology produces hydroxyls to neutralize bacteria and viruses. PlasmaWave is an ionizer. It can be switched off or on as desired by the user.

Air Quality Indicator

The air quality indicator will display the current air quality by illuminating specific colors depending on what air quality is detected via the smart sensor.

Winix C535 air quality indicator will display three states. When the indicator lights up blue, then the air is good, orange means the air is not good, and when you see red, then the air is horrible.

Smart Sensor

The smart sensor detects odors in the air. Based on that, it determines the speed of the device if auto mode is on.

Based on the smart sensor’s detected air quality, the air quality indicator will illuminate specific colors. I have described this process above in the air quality indicator section.

Sleep Mode

When sleep mode is on, the Winix C535 is barely hearable. The device produces almost inaudible sound, 40.8 dBA. I used the Winix C535 in the bedroom, and I can say that I didn’t even notice that the device is there, especially in combination with auto mode, which will automatically turn on sleep mode when the room gets dark. At the end of the review is the section about the volume that the Winix C535 produces at all speeds; check it out.

Timer

The Winix C535 uses a timer as an advanced option. The timer can be set to 1h, 4h, and 8h. A timer is a useful option if you like to use an air purifier for a particular period. After a set timer is up, the air purifier will turn off automatically.

Remote Control

The Winix C535 air purifier comes with a remote controller with included batteries. The remote controller controls the device from a remote location at a maximum of 20 feet from the device.

With the remote controller, we can use the following options: power (on/off), auto mode, changing fan speed, and turbo mode.

Check Filter Indicator

The check filter indicator will light up when it is time to replace the filter.

It will notify you when it is time to replace the True HEPA filter and the carbon filter.

Room Coverage and CADR Rating

Winix C535 is designed for rooms up to 360 sq. ft. AHAM verified for five clean air changes per hour in 360 sq. ft. space. Proper for medium to large size living rooms.

CADR ratings show us how good is this air purifier at purifying air by pollution. In the table above, you can see ratings for dust, smoke, and pollen.

Does Winix C535 produce ozone?

Winix claims C535 does not produce harmful ozone. Plasmawave CARB certificate has strict California state rules, which then implies that Winix C535 is actually safe to use. C535 has an ozone emission rating below the 0.05 parts per million limit, far from dangerous levels.

Winix Warranty and Customer Service

Winix offers a 2-year warranty on the C535 model. Support is accommodating, fast, and efficient. You can contact them via Facebook, Twitter, or Email. Besides, you can contact Winix through the WinixAmerica website or other international Winix websites.

The contact email for Winix support is info@winixinc.com.

The Winix support phone number in the US is (877) 699-4649.

I also tested how fast Winix customer support is. I received a reply to the message I sent to Facebook within 3 hours. In comparison, I was waiting for an email reply for about 13 hours.

Also, the team from Winix answered all the questions professionally and correctly, and I have no objections.

FAQ on Winix C535