Leitz TruSens Z-3500H Review: Great performance


The Leitz TruSens Z-3500H Linked Sensible Air Air purifier delivers efficient air purification even in bigger rooms. Its multi-stage filter scrubs pet hair, home mud and the vast majority of microscopic particles from the air, then it finishes off any microbes with a germicidal ultraviolet lamp. It is a well-specified air purifier with a robust but environment friendly fan, app management, and a helpful, separate air-quality monitor. Nonetheless, the Leitz app is sort of primary, and the Z-3500H’s community and sensor connectivity was problematic.


  • Excessive quantity, prime quality air purification
  • Quiet and environment friendly
  • PM1, PM2.5, PM10 and VOC air high quality sensor


  • Primary app
  • Connectivity issues

  • Air high quality sensorDistant sensor detects PM1, PM2.5, PM10 particulates and VOCs, telling the air purifier when it must work tougher

  • Sensible controlsLeitz’s app mirrors the bodily controls, however it additionally offers extra detailed air high quality information, and allows scheduling

  • Good, good, good, good filtrationA mixed HEPA and carbon filter removes mud, particulates, pollen, mould spores and VOCs, whereas a UV mild kills germs


Leitz could also be greatest recognized for workplace tools, however its TruSens vary of air purifiers is aimed on the house – alongside smaller industrial areas akin to outlets and lecture rooms. There are three ‘dumb’ fashions for varied room sizes, together with two sensible variations that add app management.

I’m testing the Z-3500H, a barely de-tuned model of the range-topping Z-3500. It’s designed to wash the air in rooms with a ground space of as much as 60 sq. metres (m2) – that’s in regards to the measurement of a giant kitchen/diner. It has a clear air supply charge (CADR) of 290 cubic metres per hour (m3/h) for smoke. The Z-3500 then again is appropriate for rooms as much as 70m2 and has a CADR of 325m3/h.

The Leitz TruSens Z-3500H Linked Sensible Air Air purifier, to make use of its full title, within reason huge, however it’s a wise gadget combining white and silver plastics with an eccentric, angled air output. It comes with a separate air high quality sensor that connects wirelessly. In line with Leitz, this provides a extra correct studying than you’d get from a sensor constructed into the air purifier itself.

Design and options

  • Engaging design with good controls
  • Separate air high quality monitor
  • Primary app

This is a reasonably large air air purifier, noticeably taller than these designed for small rooms. It’s not a lot wider, although, and Leitz has performed a terrific job of disguising its measurement with a tasteful and interesting design. The white plastic is enlivened by a silver mesh across the 360° air consumption, whereas the air output has an uncommon break up design, damaged up by a silver management bar.

Leitz TruSens Z-3500H plugged inLeitz TruSens Z-3500H Air Purifier plugged in and operating.
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This bar presents management over the 5 fan speeds, and a timer for as much as 12 hours in two-hour increments. You may also toggle the UV lamp or set the air purifier into sleep mode, which extinguishes the touch-sensitive buttons however doesn’t change the chosen fan pace. Slightly below the controls, there’s a numeric air high quality show, with colored lights indicating good (blue), reasonable (orange) and dangerous (purple) at a look.

Leitz TruSens Z-3500H controlsClose-up of Leitz TruSens Z-3500H Air Purifier controlsLeitz TruSens Z-3500H controlsClose-up of Leitz TruSens Z-3500H Air Purifier controls
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The Z-3500H will get air high quality information from its separate wi-fi sensor. This sniffs out three sizes of particulates – PM1, PM2.5 and PM10 – which are usually given off by car exhausts, cooking and different sources of combustion. It additionally detects risky natural compounds (VOCs), that are given off by some furnishings, paints, cleansing merchandise, and likewise cooking. It beams the readings again to the air purifier, which shows the best one, and units the fan pace accordingly.

Leitz TruSens Z-3500H wireless sensorLeitz TruSens Z-3500H wireless sensor
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Leitz’s app mirrors the air purifier’s bodily controls and provides in comparatively primary scheduling – you possibly can solely outline a single schedule, which, for instance, guidelines out setting the air purifier to run for a few hours within the morning after which once more within the night. There’s no hyperlink up with Alexa or Google Assistant, so you possibly can’t use voice management or construct the Z-3500H into house automation situations.

The app does present a helpful air high quality breakdown, displaying a VOC studying, and PM1, PM2.5 and PM10 particulate ranges in micrograms per cubic metre (μg/m3). It’ll additionally present you historic information by the hour, day, week and month, however this didn’t appear to work reliably – typically there’d be no information seen for a number of days.

Leitz TruSens Z-3500H appLeitz TruSens Z-3500H app

The ultimate app function is to point out the standing of the Z-3500H’s UV lamp and two filters. The HEPA 13 removes a claimed 99.97% of particles measuring 0.3 micrometres or extra, which incorporates most micro organism, mould spores, allergens and heavier smoke particles.

The carbon filter neutralises VOCs and another gases. You should purchase an ordinary substitute, however there are additionally two options specialised in odour or allergen removing – I did the majority of my testing with the usual filter.

Leitz TruSens Z-3500H filterLeitz TruSens Z-3500H filter
Left – commonplace filter. Proper – odour filter.

The UV lamp is contained inside a guard that sits within the centre of the filter. Leitz says it is going to final for as much as three years, and replacements can be found for about £18. The usual HEPA filter ought to final for round a yr or extra, and prices simply over £35 to switch. You’ll get by way of a further three or 4 carbon filters in that point, however you should buy a three-pack of recent carbon layers for £15.

Leitz TruSens Z-3500H fan insideClose-up of a Leitz TruSens air purifier filter system.Leitz TruSens Z-3500H fan insideClose-up of a Leitz TruSens air purifier filter system.
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  • Quiet and environment friendly
  • Glorious filtration
  • Unreliable connectivity

The Leitz’s separate sensor is a good concept, however I discovered its wi-fi vary to be very disappointing. Even line-of-sight connections had been sketchy from round 5 metres’ separation, whereas the sign appeared to be blocked if nearly any furnishings bought in the best way.

Sadly, it was the same story with the air purifier itself. Set up the TruSens app and you may connect with the Z-3500H with Bluetooth, or be part of it to your community and use Wi-Fi. I discovered I wanted to be inside a number of metres for Bluetooth to be absolutely dependable.

Wi-fi community connectivity was so poor as to be unusable, with the air purifier repeatedly dropping its connection. I attempted placing my router into its most elementary mode, however even with a direct line of sight, Wi-Fi remained unreliable. I attempted to use the obtainable firmware replace, however repeatedly bought a ‘Obtain failed’ message.

Leitz TruSens Z-3500H download failedLeitz TruSens Z-3500H download failed
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Luckily, issues are significantly better elsewhere. The Leitz TruSens Z-3500H is barely uncommon amongst air purifiers in that it creates a slight breeze, quite than a extra diffuse motion of air. Some cleaned air exits straight up from behind the management bar, whereas the rest emerges, angled ahead barely, from the grilles in entrance. That mentioned, it’s not sufficient to double up as an efficient fan on a scorching day. I measured as much as 3.6 metres per second (m/s) from simply 15cm away, however from a metre away my anemometer might solely detect any airflow on the Turbo setting.

It is a quiet air air purifier at its lowest speeds. From 15cm away I measured the sound at 30.5dB on the bottom, Whisper setting. This rose to 41dB on pace 1. Issues began to get a lot noisier at pace 3, reaching 62dB, and 72dB in Turbo mode. From a metre away, sound ranged from a whisper-quiet 25dB as much as 54dB on Turbo.

Leitz has fitted the Z-3500H with a DC motor, which helps to elucidate its comparatively modest energy use. It consumed simply 8.3 Watts in Whisper mode, rising to solely 24W on pace 3. Turbo mode was comparatively power-hungry, although, demanding 58W. I took all of those measurements with the UV lamp on – turning it off diminished energy consumption by about 5W. The distant sensor makes use of a separate mains connection, however its energy consumption was beneath the 1W minimal of my meter.

In apply, you’ll most likely depart this air purifier in Auto mode, the place it robotically adjusts its pace to match the air high quality. Which means it’s prone to spend a lot of its time ticking over in one in all its lowest two speeds, besides once you’re cooking or cleansing. Whereas testing it I managed to burn toast, which despatched the particulate counts rocketing and prodded the fan pace up by a few ranges. Even once I was cooking meals extra rigorously, the Z-3500H would sniff it out and pace up barely.

Leitz TruSens Z-3500H topLeitz TruSens Z-3500H top
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This air air purifier excelled in my difficult smoke check. Shut in a small room with a burning smoke pellet, it stepped itself as much as Turbo mode inside seconds. After three minutes it had lowered the room’s PM2.5 rely from our meter’s most 999 all the way down to a (nonetheless harmful) 594. Inside six minutes, this studying had dropped into the reasonable vary – that’s about twice as quick because the Levoit Core 300S managed to wash up in the identical check. In simply one other minute air high quality fell beneath 50, rated ‘good’, and the fan pace started to cut back robotically.

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Do you have to purchase it?

You need glorious performance: This air air purifier reacts shortly to deteriorating air high quality and performs strongly throughout the board

You need higher sensible options: The app and connectivity listed below are disappointing.

Ultimate Ideas

It is a well-designed air air purifier appropriate for pretty massive household rooms. Supplied you don’t place the Z-3500H and its sensor too far aside, you possibly can set and overlook it whereas it really works away to maintain the air recent. Its UV lamp offers a welcome additional defence towards airborne diseases, too.

At this value, although, it’s fairly a disgrace that it couldn’t keep a secure Wi-Fi connection and that its app is somewhat primary. The Dyson Air purifier Sizzling+Cool Formaldehyde has extra options and a significantly better app, however it’s additionally considerably costlier.

How we check

Not like different websites, we check each air air purifier we evaluation totally over an prolonged time period. We use trade commonplace exams to check options correctly. We’ll at all times let you know what we discover. We by no means, ever, settle for cash to evaluation a product.

Discover out extra about how we check in our ethics coverage.

Used as our primary air air purifier for the evaluation interval

We check sensible purifiers with their apps and we check Amazon Alexa and Google Assistant compatibility.

We time how lengthy it takes every air purifier to take away smoke from a closed room.


How lengthy do TruSens filters final?

Leitz says the anticipated lifetime of the HEPA filter is 12-15 months, however the carbon filter solely lasts round 3-4 months. The UV lamp is replaceable, too, however it ought to final 1-3 years. Like all air purifiers, utilizing a filter for too lengthy will result in diminished performance. You may lengthen a filter’s efficient life by eradicating it and vacuuming home mud from the outer floor each month. The Z-3500H’s outer pre-filter layer could be rinsed below the faucet to assist restore its performance.

What number of years do air purifiers final?

Air purifiers are basically a fan with a filter, so we’d count on a easy mannequin to final for a number of years of standard use.

Does the Leitz TruSens Z-3500H Linked Sensible Air Air purifier actually work?

Air purifiers do scale back the degrees of pollution and allergens within the air. In addition they filter out mould spores, pollen, micro organism, and a few viruses. There’s anecdotal proof to recommend they might help with allergic reactions, and by lowering particulates within the air they might assist scale back the lung and circulatory harm related to some recognized pollution.

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Quiet Mark Accredited

Dimension (Dimensions)



Launch Date

First Reviewed Date

Mannequin Quantity

Voice Assistant

App Management

Filter sort

Filter life

Max room measurement

Smoke CADR

Variety of speeds

Auto mode

Filter substitute mild

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