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Clean-tech Review: Air Purifier with UV-C & HEPA

FEBRUARY 2021 UPDATE – in January Clean-tech was suspended from Kickstarter. However, no explicit reason was provided by Kickstarter. Clean Tech has moved to IndieGoGo and still plans to honor early bird pricing. They provided this detailed explanation about the suspension. Clean Tech says they are still moving forward with manufacturing with delivery starting in February, 2021.

2-Stage, HEPA and UV-C Light Purifier

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Clean-tech Air Purifier

The Clean-tech air purifier is a 2-stage system that combines traditional HEPA filtration with the power of a medical-grade UV-C light system. When contained, UV-C light can be used to destroy airborne bacteria in a way that is frequently used in medical settings or other sterile environments. This purifier can treat up to 200 sf and is simple to setup and use. In our tests, it was able to reduce PM2.5 0.8. In addition, the independent lab testing data shows virus and bacterial removal rates of 99.99%.Check Price

Pros

  • 2-stage system that uses a 360° HEPA filter and a large UV-C bulb
  • Reflective mirrored coating on the interior helps to enhance the power of the light
  • Smaller footprint for flexible use
  • Manufactured by Foxconn (same company who builds many Apple products)

Cons

  • Not many bells and whistles. No smartphone connectivity, no scheduling, no auto mode.
  • UV-C Bulb replacement isn’t easy (you’ll need to do it every 2 years)
  • Relatively small coverage area at 200 square feet

Clean-tech Design

The design of the Clean-tech air purifier takes a different approach to air purification. Instead of relying primarily on HEPA filtration, Clean-tech’s main strategy is actually UV-C light.

Clean-Tech air purifier design
Design of the Clean-tech air purifier

UV-C light is commonly used in medical environments and kills bacteria and allergens at a molecular level, instead of just capturing it inside of a filter.

Clean Tech assembly

What is UV-C light?

UV-C light falls in the light spectrum right before visible light.

UV-C ultraviolet light spectrum
Image Source: www.uvdi.com

It can be harmful to the naked eye or if overexposed, but if the light is contained, it can be useful to target and destroy harmful bacteria and viruses.

UV-C bulb housing on the Clean-Tech air purifier

What does it look like?

This air purifier has a similar body style to many other purifiers on the market. It has a matte white shell with simple controls, air intake on the bottom, and air outlet vents at the top.

RELATED: Best Air Purifiers of 2020

The Controls

The controls on the Clean-tech air purifier are incredibly simple. There is an on / off touch-activated button, which also controls the fan speeds.

Top of the Clean-Tech air purifier
Top of the Clean-tech air purifier

It’s one button and two lights:

  • One light = low power
  • Two lights = high power
  • No lights = off
Clean-tech air purifier; one light = low power
Clean-tech air purifier; one light = low power

Aside from adjusting the two fan speeds, there are no fancy modes or settings—no Auto Mode, Sleep Mode, Timers, or smartphone integration.

How does it work?

  • Step 1: Dirty air enters the system at the bottom, through the air intake vents.
  • Step 2: The air passes through a HEPA filter located at the bottom of the unit. This filter acts as the first line of defense from larger particulate that may enter the system.
  • Step 3: Ultra-fine particulates that make it pass the HEPA filter are sanitized by the UV-C light system at the core of the system.
  • Step 4: Clean air is pumped out of the top vent.

The Purification

Let’s talk a minute about the purification system. This purifier uses a 2-stage system: HEPA and UV-C. Here’s exactly how they work and why each stage is important.

#1: The HEPA Filter

As mentioned above, the HEPA filter is located at the bottom of the purifier and captures the larger particles that may enter the system right after the air is sucked in.

Clean-Tech HEPA filter  - air purifier
Clean-tech HEPA filter

Like traditional HEPA filters, it uses a fine folded paper material that is designed to trap debris and particulates. When the filter has exhausted its life, you just remove the filter, throw it away, and pop in a new one.

NOTE: The Clean-tech HEPA filter is not washable.

This filter is important because it captures the larger debris which would likely be too large for the UV-C light to fully destroy.

#2: The UV-C Bulb

The second stage of purification involves a UV-C light bulb, which is the core of the Clean-tech system.

Clean tech bulb

This bulb is a powerful 254 nm, 12.5″ long quartz light tube. The bulb is further intensified by a mirrored surface on the interior of the purifier.

UV-C light bulb on the Clean-Tech air purifier
UV-C light bulb on the Clean-Tech air purifier

The UV-C light reflects off of the mirrored surface and is able to sanitize even more bacteria and viruses from the air.

How effective is the UV-C bulb?

In addition to the mirrored surface, the length of the UV-C bulb is another impressive feature. At 320 mm, the bulb is over 75% the height of the purifier and over 3X the length of a traditional UV-C bulb on the market (at a similar price range).

RELATED: Want more UV-C technology? Check out our review of the Lume sanitizer. It’s a box you can put stuff in and then sanitize it.

This system is important because it is able to sanitize particulates instead of capturing it.

Clean-tech Performance

To assess the performance of the Clean-tech UV-C air purifier, we put it through the standard Modern Castle test that all of our air purifiers go through.

Here’s the process:

  1. Use an air quality meter to determine current air quality (prior to testing).
  2. Run the air purifier for 1 hour.
  3. Use the same quality meter to remeasure the quality.
Air Quality Testing meter
Electronic testing meter we use to measure particulates and air quality

Baseline

  • PM2.5: 1.5
  • PM10: 2.8
  • Particles: 209
  • AQI: 6

After 1 Hour

  • PM2.5: 0.8
  • PM10: 1.4
  • Particles: 119
  • AQI: 3

Within 1 hour, the Clean-tech only removed about 46% of air particulates from the medium-sized room we tested in (approx. 12’x12′). This unit improved PM 2.5 air quality by 43%.

Why are the numbers not as good?

Our primary air purification performance test is really designed to look at particulate removal, which isn’t the main function of the Clean-tech. So from that perspective, it’s not surprising the particulate removal wasn’t as good as many other purifiers we’ve tested (though it’s far from bad).

The goal of a UV-C sanitizer is not to remove particulate, but to make said particulate sanitized by destroying bacteria and viruses that may be airborne on that particulate.

The lab test results below (paid for by Clean-tech, but tested at an independent lab) show performance for both bacteria and virus removal.

Click below to read more about the Clean-tech bacteria and H1N1 performance tests:

Bacteria Tests

Click for full report

Virus Tests

Click for full report

Don’t feel like reading the details? In short, here is the outline and results of each test:

  • Bacteria test: a 120-minute test that looks for the presence of staphylococcus albus and E. coli, two relatively common bacteria families. (6 tests total)
  • H1N1 test: a 90-minute test that looks for the presence of H1N1 in the air (3 tests total)

The results of the bacteria tests, as well as the H1N1 tests, were 99.9% removal of all bacteria & viruses tested for during the duration of all tests.

Clean-tech Size & Dimensions

The Clean-tech purifier is on the smaller size. It is only 17″ tall and 8″ on each size. It’s small enough to sit comfortably on a tabletop or counter. Though it could could also sit on the floor.

Size of the Clean-tech air purifier
Size of the Clean-tech air purifier

The exact dimensions are as follows:

  • 17″ high
  • 8″ wide
  • 8″ deep

Given the small form factor, the Clean-tech has a relatively small coverage area. This purifier can treat up to 200 sf of area.

Clean-tech sizing
Clean-tech sizing

What’s in the box?

The Clean-tech purifier comes with a simple set of parts and it’s basically just the bare necessities of what you need to get working.

Clean-tech air purifier - parts disassembled
Clean-tech air purifier – parts disassembled

Here’s what’s included:

  • Clean-tech shell with UV-C housing
  • Plastic base
  • HEPA filter
  • 4-leveler feet for final setup

FAQ: What is a HEPA filter?

Usability

In terms of usability, the Clean-tech is simple. To get going, you can simply follow the steps below:

  1. Unbox the purifier and remove all packaging.
  2. Make sure the HEPA filter is installed and packaging removed (UV-C bulb should already be installed)
  3. Plug the unit in.
  4. Press the power button and select a fan speed (speed 1 or 2, which is low and high, respectively)

After you setup the Clean-tech, you can also adjust the feet on the base to ensure that the purifier sits level. They simply screw into the base using long threaded rods and black plastic feet.

Clean-tech leveler feet on the base
Clean-tech leveler feet on the base

Maintenance

Maintenance on this unit is similar to most other air purifiers. The list of maintenance items is short and really only includes 2 things.

  1. Use a dry cloth to wipe down the air intake and outlet vents.
  2. Replace the HEPA filter as needed.
  3. Replace the UV-C bulb as needed.

To change out the HEPA filter, remove the base and slide out the filter.

Removing or installing the Clean-tech air purifier HEPA filter
Removing or installing the Clean-tech air purifier HEPA filter

Changing the bulb is more complex. The manufacturer has stated they will be releasing a guide on how users can change the bulb in the future.

The UV-C bulb is rated to last 18,000 hours or about 2 years of continuous use.

The first design iteration of the Clean-tech is more complex to replace the bulb. The manufacturer has stated that they plan to develop a more modular design in the future so bulb replacement is easier.

Is the Clean-tech a good value?

The value of the Clean-tech unit is pretty good and we’re not the only ones that tend to think so.

What Others Say…

This product originally launched on Kickstarter at the end of October 2020 and was fully funded within the first 2 hours of the campaign launching.

Rewards in their campaign varied, but mostly included a Clean-tech purifier and various perks and bonuses.

Clean-tech air purifier - crowd funding goal

What We Say…

Aside from having widespread community support, this purifier also reviewed pretty well in our private testing.

While the particulate count wasn’t drastically different, this unit was easy to use, had a notably large UV-C bulb installed, and an intuitive nice user-interface.

What’s Good

  • Larger UV-C bulb
  • Intuitive user-interface
  • Smaller footprint

What’s Not So Good

  • Doesn’t remove particulates as well as others
  • Pretty basic design; Limited bells and whistles
  • Small coverage area of 200 square feet

Despite the shortcomings, I still consider this is a good value, especially for UV-C purification.

Should you buy the Clean-tech purifier?

I would recommend the Clean-tech if you’re looking for the following in a purifier:

  • UV-C technology: If you’re specifically looking for safe and effective UV-C technology, the Clean-tech has you covered. It uses a bulb 3X larger than conventional UV-C bulbs in other units on the market. The larger bulb tends to yield greater results since there’s more air space and time for the system to treat pollutants before redistributing back into the air.
  • Crowd-funded support: For a different type of product that has gotten it’s start through support within the community, the Clean-tech is also a great option. The support for this purifier was quick and continues to grow as the campaign comes to a close at Kickstarter.com
  • Smaller footprint: If you’ve got a smaller space and don’t need a huge unit, you may prefer the smaller footprint of the Clean-tech purifier. It’s easily small enough to sit on a table or countertop, but could also be fine on the floor. In addition, it’s only able to purify spaces up to 200 square feet.

Click here to learn more to check the price on the Clean-tech air purifier.

Updates

  • February 1, 2021 – Added an notice at the top of the page about the Kickstarter suspension.
  • December 10, 2020 – Clean-tech corrected themselves and asked us to re-state that the coverage area is 200 square feet.
  • December 8, 2020 – Corrected an error where we incorrectly listed the coverage area as 200 square feet, when it is actually 1,200.
  • December 8, 2020 – Initial version of the page was published.
UV-C Air Sanitizing
  • 96%
    Design - 96%
  • 94%
    Performance - 94%
  • 96%
    Quality - 96%
  • 97%
    Usability - 97%
  • 96%
    Value - 96%
96%

Summary

The Clean-tech air purifier is a 2-stage system that relies on HEPA filtration combined with UV-C light sanitization. UV-C light has been tested to be effective at removing bacteria and viruses without the costs of disposable filters. While the Clean-tech still uses a small HEPA filter, the large UV-C bulb is the majority of the air purification on this unit. It’s designed to treat areas up to 200 sf. and has a small footprint, only 8x8x17″H. Overall, I was impressed with the Clean-tech purifier and its ability to clean and sanitize the air.

About Derek Hales

Derek HalesDerek Hales is the Founder and Editor-in-Chief of ModernCastle.com. He has been featured in Fast Company, Reader's Digest, Business Insider, Realtor.com, She Knows, and other major publications. Derek has a Bachelor's Degree in Business Administration from Kansas State University. Hales has been testing and reviewing products for the home since 2014.

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