TruSens Z

This air purifier for large rooms includes UV purification and Alexa support, but its clean air delivery rate is low and it's very noisy when running at full tilt.

$279.00

Looking for high-end air purification performance in a reasonably priced package? The TruSens Z-3500 has plenty to recommend it, despite a couple of minor flaws.

The "large" version of the TruSens smart air purifier is reviewed here. The company also offers a "medium" (the TruSens Z-2500) that sells for $229. Both models cut a familiar design profile: a white and silver cylinder that draws air in from 360 degrees around the base, emitting it through two vents at the top. One vent is aimed straight up and the second at an angle. The design helps the purifier cover 750 square feet of space with two air changes per hour. Oddly, the company specifies a single CADR (Clean Air Delivery Rate) of just 192 cfm (cubic feet per minute), which is fairly low for a unit of this size: 29 inches tall, 10 inches wide, and weighing 12.6 pounds.

This review is part of TechHive's in-depth coverage of the best air purifiers.

The TruSens Z-3500 is a good value among air purifiers that can clean the air in a large room.

A cylindrical combo HEPA-carbon filter slides into the bottom of the device, but TruSens offers a variety of replacement filters, including a pet filter, an "allergy and flu" filter, and an odor and VOC (volatile organic compounds) filter, each priced at $89. The carbon filter layer surrounding the inner HEPA filter can also be replaced separately for $39 if you don't need to replace the entire affair. (The carbon filter should be replaced every three to four months, but the inner HEPA drum can last up to 15 months.) The TruSens Z-3500 also includes a UV bulb for virus zapping. The bulb has a 2- to 3-year lifespan; replacements run just $15.

The TruSens Z-3500's controls are all within easy reach if you don't want to pull out your smartphone and launch the smart air purifier's app.

Christopher Null/Foundry

Onboard controls present no surprises, with five fan speeds, a light-dimmer/sleep mode, and a countdown timer that cycles through 2, 4, 8, and 12 hours until shutting off. The UV light can be toggled from the control panel, too. A numeric display provides an indication of overall air quality: A combination of PM1.0, PM2.5, PM10, (PM is an acronym for particulate matter) and VOC levels. A light ring around the control panel color codes conditions among three levels from blue (good) to red (poor). The TruSens app displays a fine-tuned breakdown of the aforementioned airborne pollutant levels.

A TruSens Sensor Pod comes with the air purifier. This is a remote, AC-powered indoor air quality monitor that can be placed up to 49 feet—within line of sight—from the purifier. Using two sets of sensors ostensibly improves the purifier's accuracy, since the air immediately around the unit will be cleaner if the appliance is doing its job.

The TruSens app identifies the types of airborne pollutants it removes from the air and provides statistics for 7- and 30-day periods.

Christopher Null/Foundry

You connect the TruSens Z-3500 to your 2.4GHz Wi-Fi network, and registration is a quick, painless process through the TruSens app. The app itself offers a few extra features, including a scheduling system, filter life breakdown for each of the three components, and a deep dive into the four air-quality metrics mentioned above. The unit also keeps a robust history that charts overall air quality by hour, day, week, and month; plus, a function that reports the AQI (Air Quality Index) for the outdoor air at your location.

Alexa users can control the TruSens Z-3500 with voice commands via a smart speaker to turn the unit on, set the fan speed, and so on. A slip included with the user manual spells these capabilities out in detail. There is no support for Google Assistant or Siri (the unit is not HomeKit compatible either).

A remote air quality monitor tests the air up to 49 feet from the air purifier to supplement the findings of the appliance's primary sensors.

Christopher Null/Foundry

The TruSens app is easy to use, and the amount of information provided is helpful without being overdone. That said, the power button on the app seems a bit curiously designed. Tap this icon and you’re presented with a second screen with separate "on" and "off" buttons. It would be more efficient if the first power button simply toggled between on and off states.

The purifier itself has a few faults, the biggest (aside from its relatively low CADR) being its volume level. TruSens says the appliance's noise level ranges from 30- to 60dBA, and it's deafening when operating at full bore. Even in sleep mode, I found it too loud for nighttime use in the bedroom. Speaking of which, sleep mode turns all the lights way down, but if you power the unit off altogether, the power button illuminates brightly. This standby indicator is so bright that it kept me up half the night. I suppose you could use it as a nightlight, but I ended up unplugging the unit in order to sleep.

The TruSens Z-3500 isn't a perfect, but $279 is a good price for an air purifier with its feature set that can clean the air in a large room—assuming you aren't using it in a room where you intend to sleep.

Christopher Null is a veteran technology and business journalist. He contributes regularly to TechHive, PCWorld, and Wired, and operates the websites Drinkhacker and Film Racket.