Winix Signature U450 (WACU450) Air Purifier Review by Garth Wernsman
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A bit pricey, but the Winix U450 is bound to be worth the cost for a lot of allergy sufferers. This air purifier delivers solid value for the dollar.
The Winix U450 is one of the PlasmaWave air purifiers that has justifiably earned the company a great reputation. All of them are high quality, high cleansing power, and attractive. This one is no exception.
The body is largish at 25.59″ high x 17.32″ wide x 10.24″ deep. You can still place this unit in a number of possible places around the house, a flexibility that’s helpful since house floor plans are so varied these days.
And, at just 19.40 lbs, you can move it from one to the other without a lot of strain if you don’t care for your first choice. You might want to do that, for instance, if you discover that you’re not getting good air movement when in one place. The intakes are on the side and the vent is on the top, so it does need some space all around to operate efficiently.
Airflow & CADR Specs
The airflow of the U450 is impressive:
- Quiet: 78
- Medium: 148
- High: 215
- Turbo: 300
(all figures CFM, cubic feet per minute).
The CADRs (Clean Air Delivery Rates) are equally good:
- 343 Pollen
- 298 Dust
- 291 Smoke
Winix might call this a high-end model but I would still place it in the midrange. And for a midrange model, those numbers are on the high side, especially the pollen rating. The reason isn’t hard to find. The filtration system on the Signature U450, like the other Winix models, is very, very good.
5-Stage Filtration System
Stage 1 consists of the company’s pre-filter. It’s designed to remove the largest particles – pet hair, dust, lint. All that isn’t terribly harmful in the air, but neither is it good in itself, and removing it helps the other filters function more effectively. Most air purifiers today have one. The Winix unit, however, also has an anti-bacterial coating that few others have and it’s washable.
Stage 2 is where the U450 starts to reveal how it is a step above much of the competition. It features a filter coated with silver atoms, a natural anti-microbial material. It helps remove dust mites, mold, fungi, and other nasty little creatures that deal our lungs a fit.
Stage 3 is a True HEPA filter, one which works far better than the legal minimum. It’s rated to get 99.99 % of particles down to 0.3 microns and real-world tests show that it actually achieves that. It gets rid of tiny dust particles, pollen, pet dander (a sore spot for lots of allergy sufferers), and even smoke.
Stage 4 houses the Winix Advanced Odor Control carbon filter. The word “odor” signals something a little less benign than mere unpleasant smells. Foul-smelling chemicals are frequently mild toxins, especially to the chemically sensitive among us. It neutralizes ammonia, for example, a special problem sometimes for those with pets in the house. It’s a nice added benefit that this filter is also washable.
Stage 5 contains the Winix proprietary PlasmaWave technology. I’ve written about this whiz bang feature in detail elsewhere. Suffice to say here, it generates both positive and negative ions that combine with water vapor in the air to form hydroxyls.
That may sound like nasty stuff but it’s actually the opposite. They float around room air in harmless concentration and attack viruses, bacteria, and a wide range of airborne chemical compounds. Then, a beneficial chemical reaction takes place to create water vapor and other harmless molecules.
Display & Controls
All that goodness in air purification is supported by a large array of equally good ergonomics.
An air quality sensor (A, F) inside monitors the quality of the air passing through the unit and automatically adjusts the fan speed (G, H) when Auto mode (B) is on. Or, you can set it manually if you prefer.
The LEDs that show various indicators will be dimmed for nighttime use. So, if you operate the U450 in your bedroom, and are sensitive to illumination, a light sensor (J) will dim the lights and sets the fan speed to QUIET when the room becomes dark. My wife in particular is very grateful for that feature.
Another example of superior design is the Filter Replacement indicator (C, D). Many air purifiers have something like this to show when to swap out a filter. This one is better because, unlike far too many models, it operates via actual usage not just on a “how long have you owned it” basis.
The electronic controls are all effortless to use. For example, some are sensitive to even the minute levels of ozone the PlasmaWave creates. You can turn it off merely by holding down the button for a few seconds. It’s not hard to detect when it’s off or on, either. A little animated “wave” graphic (E) shows up when it’s activated.
Noise & Electricity Usage
Like all Winix air purifiers to date, the U450 is a pretty quiet unit. Since it can operate on “auto”, it can downshift or upshift the fan as needed, based on pollutant concentration. On the lowest setting, it generates a mere 29 dB. That level is practically inaudible. When running at the Turbo level it puts out a modest 56 dB, noticeable but not annoying.
The juice consumed is equally almost-nothing to modest. At the lowest fan speed it consumes around 10 watts; even at the highest it’s only 110 watts. It rarely needs to operate on Turbo but if the power consumption is around that of a single, bright incandescent light bulb, I’m fine with that.
The company touts the Winix U450 as a premium air purifier for large rooms. The 450 in the name, after all, corresponds to the rated coverage. But those numbers are always overstated for real-world use, though they remain useful for comparison shopping.
Depending on your room and needs, I put it about 3/4 of that number, which is pretty good. An 18′ x 18′ room with an 8′ ceiling is still pretty ample size. However, that puts it in the midrange in my book. With that modification, I’d say the CADRs are very good and the Winix purification technology is top notch.
That combination makes this air purifier one I can solidly recommend.