Winix U300 Air Purifier: Trusted Review & Specs

The most powerful Winix U300 (Winix WACU300) to date is packed with the latest air filtration process and enough performance for those unable to afford a fully-fledged flagship. It is the first representative of the Winix Signature Series, which is also the premium offering of the older Winix P300. So we will see if this air purifier will be, again, the best bang for the buck in Winix lineup, even compared with its cheaper siblings in our Winix U300 Review.

The Winix U300 is discontinued, so if you want a great performer at the same price point, you don’t need to find anywhere because the Winix AM90 is so great to be your best companion. Also the latest Winix 9800 is released, packing with more power.

Winix U300 ranks B in our air purifier ranking list. We give the biggest and most thorough database of air purifier reviews in the world.

In Breathe Quality, we have reviewed all air purifiers under these sections. Also, we guarantee that:

  • We provide honest reviews (both pros and cons) so that everyone can make the best decisions.
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winix u300 review

  • Powerful air filtration process
  • Clean design
  • Great value
  • Slick interface

  • Some still claim that PlasmaWave irritate asthma
  • High filter replacement cost
  • Discontinued

Since 2003, Winix is not a strange name of air purifiers in the U.S. It is not a bluff to say the Winix is the best Asian air purifier brand in the U.S market right now, especially when others like Coway or Sharp don’t try to bring more of its air purifiers to expand in the North America. The Winix U300 inherits all the greatness of the previous Winix P300, and improve the internals to solve even the hardest task in air cleaning. I hope you are ready for our Winix U300 Review.

Winix U300 Price

Of all air purifier brands outside of the U.S, Winix is undeniably the most active one. The Winix U300 is the next-gen air purifier, an impressive air purifier to replace the old Winix P300. It is the evidence that the gap between flagships and budget air purifiers is still closing.

The thing is, the “U” part of the name doesn’t mean anything you can think of for one air purifier in Signature Series of Winix. “Upgraded” is the most suitable word for the Winix U300, but is that really enough to justify the change in the price? Let’s take a closer look.

The Winix U300 has a price of $259, but it has dropped to only $220 on sale in Sylvane or Amazon, so the price at the moment is nearly the same with the old Winix P300. Be sure to check our deal to have the best and up-to-date price of this Winix U300.

With only $259, the Winix U300 is apparently the most affordable Winix air purifier with the next-gen 5-stage air cleaning system. However, it seems the Winix U300 has been discontinued. There are new air purifiers in Winix lineup, the Winix C909 and Winix 9800, with better performance and smart features than our today unit.

Though the Winix U300 is one of the most well-rounded air purifiers you can purchase if you’re on a budget or otherwise, it has many competent contenders in the low-range market. The Honeywell HPA300, Medify MA-40 and Coway AP-1512HH are the best budget long-term investments, with the fantastic performance that match the Winix U300 easily. We also have here the Levoit Core 400S, Levoit Vital 200S and Levoit LV-PUR131S as budget smart air purifiers to choose, and I must admit that whatever you opt-in for your home, it is certainly a wise option.

Top Winix U300 deals right now

Winix U300 Signature Large Room Air Cleaner with True HEPA 5-Stage Filtration, PlasmaWave Technology and AOC Carbon.

The Winix U300 features Winix’s signature 5-stage cleaning system, to deal with your everyday indoor air pollution. Energy Star rating.

Related post: Best air purifier 2023.

Winix U300 Design and Size

It has been a long time from the original Winix P300, and the Winix U300 is still easily mistaken. There is no difference between them, and you can only differentiate one from another by the larger depth of the Winix U300. Actually, the Winix U300 is 10.4 inches in depth, while the previous Winix P300 is only 8.7 inches. Other dimensions, however, remain the same in the Winix U300.

To spot the difference, you can check for the new logo of the Winix U300 Signature on front of this air purifier. The material to make these air purifiers, especially the Korean air purifiers, are mostly the same. There is a tough, smoothly curved plastic frame around the air purifier front.

Just like any other Winix air purifier, for example the Winix 5300-2, Winix 5500-2 and Winix C535, the Winix U300 uses the classic bottom-to-top airflow system concept. Under the front plate, the Winix U300 uses the 360° air intake to improve the efficiency of pulling polluted air.

The lean-on-top control panel of the Winix U300 has some minor improvements to the old versions of Winix FresHome, however, it is nearly identical to the old one.

winix u300 review


Winix U300 weighs 13.4 lbs, and you can lift it and move it around your home with the built-in handle.

Related post: Best air purifiers for bedroom.

Winix U300 Filters

To decide the performance of one air purifier, normally we will look at the quantity of air filters, as well as its air filter types. The Winix U300 differs from the old ones thanks to the powerful 5-stage air cleaning system, just like the Winix WAC9500.

  1. Pre-filter – The polluted air must pass through a pre-filter. This pre-filter will help capture the large objects of contaminants, such as pet hair and even some kinds of pet dander. This filter can be washable to work permanently.
  2. CleanCell Anti-Bacterial Treatment – Though this is not a physical filter, the treatment also provides a layer of protection to your air quality.
  3. True HEPA filter – The True HEPA Filter that captures 99.97% of down to 0.3 microns allergens, virus particles, pollen, mold and fungi particles.
  4. Activated Carbon filter – Made of high-grade granular activated carbon, this Activated Carbon filter will eliminate odors and smokes, also reduce the common household chemicals.
  5. Winix PlasmaWave – This technology is one kind of ionizer, which can further reduce the amount of pollutants. Can be switched on/off.

First, the Winix U300 uses a real washable pre-filter that can effectively traps large particles such as pet hair, lint, dust and fibers. The filter cassette has a mesh shield to improve the performance and significantly inhibit the growth of impurities on surface of HEPA filter. Moreover, the innovative CleanCell antimicrobial treatment of Winix covers the pre-filter, to reduce the development of bacteria, fungi, mildew, molds and dust mites.

As the core of the Winix U300’s air filtration system, we have the combination of both True HEPA filter and a premium quality carbon filter to adsorbing and neutralizing strong odors caused by ammonia, and bacteria. The Activated Carbon filter can last for 1 year with regular washing.

The last but not least, the Winix U300 makes use of the powerful patented PlasmaWave technology. This treatment can remove airborne viruses, chemical vapors, gases, and remaining odors by naturally forming hydroxyls to neutralize the pollutants at the molecular level, and turn them into the water.

We have experienced the powerful 5-stage air cleaning system in the top dogs of this Korean company, especially in the Winix AM90, Winix HR950 and Winix HR1000. But I still tested the Winix U300 with the most careful test, in a room of 200 square feet for 1 hour. I also locked the Coway AP-1512HH, Honeywell HPA300 and AeraMax 300 to compare with this air purifier. As you can see from the chart below, the Winix U300 has the same efficiency as the Coway AP-1512HH and Honeywell HPA300 as 99.95% for trapping any particles down to 0.3 microns. This is also the same performance of the latest Winix C555. The AeraMax 300 and Oransi OV200 have lower efficiency, with only 99.93% and 99.5%, respectively.

winix u300 review

With the new air filtration process, the Winix U300 will cost you much more than the Winix P300, and you can buy the Filter B for $89. The air filter cost is quite higher than many air purifiers in the same price range, like the Coway AP-1216L or Coway AP-1512HH. Actually, the air filter cost for one year of use is equal to a $479 Oransi Max, which is really high for a low-range device.

Related post: Best air purifiers for allergies.

Winix U300 Room Coverage

Just like the old Winix P300, the air purifier of Signature Series is suggested for a room size of 300 square feet. Such room coverage is recommended for many air purifiers in this price range, like the Honeywell HPA200, AeraMax 300 or even Airmega 200M.

The ACH of Winix U300 is 4X. For an air purifier with high fan power, the Winix U300 can exchange the air in your room every 15 minutes.

The CADR of Winix U300 is 197 Dust/ 197 Smoke/ 214 Pollen (cfm). The CADR rating of the Winix U300 is not as high as the Winix HR950 or Winix AM90, but it is still enough to clean a room of 300 square feet quickly.

Related post: Best large room air purifiers.

Winix U300 Sound

In real use, I’m always happy with the silent operation of Winix air purifiers. The Winix U300 is not an exception, and for example of one day, we can use this air purifier in our lab without any interference.

This is because of the noise level of only 28 decibels on lowest fan speed of the Winix U300. Even if you are running this air purifier on highest speed, the noise level is just 52 decibels (db), such noise level of very normal conversation at home. As you can see, the Winix U300 is another silent air purifier of this brand.

Winix is an air purifier brand with fame in making low noise level air purifiers. Even with a much more fan power, this company improves the fan to reduce the noise level as low as possible. This is also the effort Winix tries to do to reduce the ozone emission from its PlasmaWave technology.

If you plan to run this Winix U300 in your bedroom or your office, I believe that you won’t be distracted by the noise it makes.

Related post: Best air purifiers for baby.

Winix U300 Power Consumption

One of our most FAQs is “Do air purifiers use a lot of energy?” In fact, air purifier must be used for a long time to be efficient. And power consumption is one important criteria to review if this air purifier is good or not.

The Winix U300 has the same power consumption as the old Winix P300, for only 60 watts. It is still better than the power consumption of the Winix 5300-2 or Winix 5500-2 with 70 watts, and especially if you compare with the Winix U450 and Winix P450 (110 watts).

However, the lowest speed of the Winix U300 only consumes 4 watts, which really impresses me. Again, you should remember the Winix U300 is an air purifier with Energy Star rating.

For using Winix U300 8 hours per day, it would cost you around $22 per year.

Related post: Best air purifiers for pets.

Winix U300 Additional Features

Like other Winix air purifier devices, the Winix U300 uses the accurate Smart Sensor to detect the slightest change of indoor air quality, and respond with a visual light notification in the LCD control panel. Winix call this function “Set and Forget”, because you can just turn the Auto Mode on, and just let the air purifier choose the best fan speed automatically for your home air.

winix u300 review


If you are fond of the Wi-Fi Enabled Connectivity feature, you should look for the Winix C545 and Winix AM90 instead, as they both offer this high-end feature while keeping the price to be nearly the same as the Winix U300.

To help control the Winix U300 much easier, this company also gives us a remote control in the box, to adjust the settings comfortably from a distance of 20 ft.

Next, we should mention the dimming light sensor by running Auto Mode. All the LED indicator lights can be dimmed for the overnight hours, so they won’t disturb you while you sleep.

And finally, you still have the LED indicator for filter replacement in this Winix U300.

Related posts:

1, Best air purifiers for smoke.

2, Best air purifiers for dust.

3, Best air purifiers for mold.

Winix U300 Customer Service

Established over 40 years ago, in 1973, the Winix company is truly an expert in the air purifier industry. It has many headquarters, not only in South Korea but also in both the U.S and Europe. You can reach its customer service from 9 a.m to 5 p.m, Monday through Friday, via phone or email. If you have trouble calling its service, you can email Winix America at

On its official website, the company is selling both new and certified refurbished air purifiers, of course with free shipping in the U.S only. The Winix limited warranty is two years for most of its products. During the warranty period, Winix will repair or replace the product if it fails because of a defect in material or workmanship, as determined by Winix. Remember that this warranty will be null and void if the product is used for purposes other than home, consumer purposes.

Top Winix U300 deals right now

Winix U300 Signature Large Room Air Cleaner with True HEPA 5-Stage Filtration, PlasmaWave Technology and AOC Carbon.

The Winix U300 features Winix’s signature 5-stage cleaning system, to deal with your everyday indoor air pollution. Energy Star rating.

Our verdict

I can’t believe the Winix U300 can have a very high efficiency compared with the old Winix P300, while remaining the same price. This is also the most affordable air purifier with the signature 5-stage air cleaning system of Winix, so if you are a fan of this Korean brand, you shouldn’t ignore the power of the Winix U300, or maybe, the extra-large room Winix U450.

Together with its brother, the Winix U300 has been discontinued. However, you can have the Winix AM90 with the same great performance and much better features.

Winix U300 Air Purifier: Trusted Review in 2024
Winix U300 Air Purifier: Trusted Review & Specs

Winix U300 Reviews and Specs (Air Purifier Trusted Reviews in 2024). ✓ Cleaning Power: True HEPA ✓ Large room: 300 sq ft ✓ Value: 3.9/5 ✓ Certified Review.

Product Brand: Winix

Product Currency: USD

Product Price: 259

Product In-Stock: SoldOut

Editor's Rating:
  • Performance
  • Features
  • Annual Cost
  • Design
  • Price


This air purifier has been discontinued.