Clean-tech: Air Purifier With UV-C and HEPA – Review

It kickstarted as an innovative air purifier featuring the largest UV-C light on the market. But does it live up to the hype?

Our Verdict





Operating cost


Value for money


Ease of use




I tested the Clean-tech air purifier back in 2021, and since then, I have only used it a few times to recheck some features and reconsider the conclusions I pointed out in this review.

It’s still an innovative air purifier, and the concept of a large UV-C light as the main filtration stage is great. However, it delivered poor results in my performance tests and is slightly louder than competing air purifiers. Also, the hype around it has drastically reduced since its launch.

Frankly, if you ask me, I would prefer a classic HEPA air purifier. Yes, I’m aware that the Clean-tech also includes a HEPA filter, but it’s an H11, which isn’t efficient enough. We have reviewed many excellent air purifiers here at Air Purifier First that are much more affordable and outperform the Clean-tech in almost every aspect.

If you have questions about the Clean-tech air purifier, please feel free to ask in the comment section below.

What we really like?

  • The Clean-tech has an incredible 24W UV-C light, which is ten times more powerful than the UV-C light on some traditional air purifiers.

  • The UV-C light actually kills bacteria and viruses, which is great, but some studies say that there isn’t enough time for a UV-C light located in an air purifier to kill a significant amount of bacteria and viruses.

  • You don’t need to replace the UV-C light that often; it lasts about two years.

  • It covers rooms of 200 sq. ft. (18.5 m²), which is the size of small rooms such as bedrooms, kids rooms, and similar.

What could be better?

  • It uses a low-quality HEPA H11 filter that performs well under the many competitive air purifiers.

  • The Clean-tech is a bit too pricey for what you get.

  • In performance tests, it didn’t show outstanding results and didn’t justify the name and the hype around it.

  • It lacks features, has only two fan speeds, and uses too much power, considering the UV-C light is only 24W.


Dimensions (inches / cm)7.87 x 7.87 x 16.5 inches (19.9 x 19.9 x 41.9 cm)
Weight (pounds / kg)8.25 lb (3,7 kg)
Clean Air Delivery Rate (CADR)-
Filtration TechnologyUV-C Light and H11 HEPA Filter
Filter Replacement IndicatorYes
Filter Life6-12 months
Number of Fan Speeds2 – Speed MIN, and Speed MAX
Air Quality Sensor No
Air Quality IndicatorNo
Auto Mode No
Smart App No
Voice Control No
Other FeaturesUV-C Light
Coverage (4.8 ACH) 200 sq. ft. (18.5 m²)
Performance Ratings
Power Consumption 36W
Operating Costs Ratings
Noise Level (low – high)53.6 – 60.7 dBA
Noise Ratings
Best Suited For
Small Spaces

Full Review

CleanTech is one of the newly formed companies dedicated to the production of air purifiers. Their earliest invention is the Clean-Tech Medical Grade UVC Air Purifier that uses two-stage filtration, an H11 HEPA filter, and UV-C light. While the main focus of this device is on filtering the air with UV-C, the main idea of the Clean-tech is to disinfect the air around you while you are there.

UV is a technology used in healthcare, medicine, and similar fields where bacteria’s practical and fast killing is needed. Clean-tech has been successfully funded on Indiegogo, with thousands of users backing the project and purchasing the product.

Clean-tech - Air Purifier Review
The Clean-tech air purifier is placed on a small desk. Photo: / Milan Antonic

Though it lacks advanced and optional features and has only two fan speed options, it is a pretty straightforward device for use. Besides, the Clean-tech is designed for spaces up to 200 sq. ft., and the independent lab tests show a 99.99% virus and bacteria removal rate (P.S. it showed much lower performance in my tests).

They started their campaign on the Indiegogo site. In order to support them and help as many people as possible who would buy this product, I decided to test it, so below you can see how the innovative Clean-Tech Medical Grade UVC Air Purifier proved in the tests I subjected it to, and whether it successfully passed.

How We Tested the Clean-tech?

1. For the filter efficiency testing, we used the Temtop LKC-1000S laser particle meter, which measures PM2.5 (µg/m3), PM10 (µg/m3), Particles (per/L), and HCHO (mg/m3) in the air, and also calculates the AQI.

2. We placed the Clean-tech in two separate performance tests, one in a 194 sq. ft. (18 m²) room and the other in a 320 sq. ft. (30 m²) room. Then, we recorded the initial air quality values using the Temtop laser particle meter and let the Clean-tech run at maximum speed.

3. After 60 minutes, we measured the new values using the Temtop laser particle meter and saved the data.

4. Next, we placed the Clean-tech in a glass box, which we then filled with smoke. Then, we measured how much time was needed for the air purifier to remove all the smoke from the box.

5. Using a special noise measurement tool, we tested the air purifier’s noise level at all speeds. We measured the noise level on the dBA scale.

Clean-tech - Noise Measuring
I tested the sound produced by this air purifier using a special noise measurement tool. Photo: / Milan Antonic

6. Finally, we measured the power usage at all speeds using an energy meter, after which we calculated how much it would cost to use the device at a particular fan speed for one month. For reference, we used an energy price of $0.12 per kWh.


Performance – Particle Removal Tests

Clean-tech is an air purifier designed for rooms up to 200 sq. ft. (18.5 m²). Accordingly, we have tested the device in two similar rooms.

The tests were identical to other air purifiers we have tested so far, mainly to better and more accurately compare the performance of the different devices and suggest the best air purifier to buy.

Clean-tech’s demonstration website contains information on third-party tests that guarantee the outstanding performance of this device. However, the results of the tests we have taken are somewhat different and not as impressive as they claim. The third-party tests confirm that Clean-tech successfully kills the H1N1 virus, as well as Staphylococcus albus and E. coli.

An important difference is that the Clean-tech kills bacteria and viruses (using UV-C light), which is much slower than trapping particles in the HEPA or similar filters.

Testing in a 194 sq. ft. (18 m²) Room

I tested the Clean-tech in a 194 sq. ft. (18 m²) room. The unit was running at maximum speed all the time.

Firstly, I put it in the room, measured the current air quality, and left it running for a while. After 60 minutes of operation, I measured the air quality again and found that the Clean-tech improved the air quality by about 76%.

Particle Removal Test Room - Comparison

Comparison between the Clean-tech and its competitors in particle removal tests in a 194 sq. ft. (18 m²) room.

If compared to some other air purifiers on the market, this results in the air cleaning performance being much lower than the average. For example, the much smaller Levoit Core 300S improved the air quality by an incredible 94% in the same room size. Even the small Aroeve MK01 made better results, with an air quality improvement of 82%.

# Starting Baseline After 60min
PM 2.5 92.1 µg/m³ 22.5 µg/m³
PM 10 129 µg/m³ 31.6 µg/m³
Particles 133659 per/L 32747 per/L
AQI 121 29

Given that the room is slightly smaller than the recommended dimensions, according to the Clean-tech website’s information, I’m a little disappointed with this result. However, it should be borne in mind that the Clean-tech kills bacteria, viruses, and other germs from the air.

Testing in a 320 sq. ft. (30 m²) Room

In another room measuring 320 sq. ft. (30 m²), which is much larger than the recommended dimensions, we tested the Clean-tech following the same principle. 

After 60 minutes of operation, the device improved the air quality by only 45% at maximum speed. I was further disappointed by this inferior result, so I left the Clean-tech running for another 60 minutes. 

After that, the device improved the air quality further. In 120 minutes, the air quality improvement had risen to a much better 67%.

# Starting Baseline After 60min
PM 2.5 78.9 µg/m³ 43.1 µg/m³
PM 10 110.5 µg/m³ 60.4 µg/m³
Particles 114463 per/L 62616 per/L
AQI 104 57

The bottom line is that Clean-tech could do very well, but it takes a lot of time, and this UV-C light technology is good but “slow.”

I think a better, higher-quality HEPA filter would make this air purifier much more efficient.

Performance – Smoke Removal Test

In the smoke test, the Clean-tech showed one of the worst performances among all the air purifiers we tested.

It needed 231 seconds to remove all the smoke from the box, which is more than 11 times slower than the Levoit Core 300S.

Smoke Box Test - Comparison

In this chart, you can see how quickly the Clean-tech removes smoke from a glass box compared to its competitors.

Even the old and bulky GermGuardian AC4825 produced a better result, removing all the smoke from the box in just 38 seconds.

Overall, the Clean-tech is one of the worst performers we have tested.


Noise Levels Test

As far as the noise level produced by Clean-tech is concerned, I don’t have much to say. The Clean-tech only uses two fan speeds, meaning you don’t have much choice but to get used to the sound of one speed or the other.

I think the noise in MIN mode could be a little quieter, especially when compared to other competing devices. At this speed, the Clean-tech produces a sound of 53.6 dBA. This problem could be easily solved if the device had a sleep mode with lower noise production.

Noise Levels Test - Comparison

This chart compares the noise levels at the minimum and maximum speeds of the Clean-tech air purifier with those of its competitors.

For example, the Levoit Core 300S produces a sound of just 41.4 dBA at the lowest speed, and the TruSens Z-1000 is also much quieter, with a noise level of 43.8 dBA.

In MAX mode, the noise produced is higher than at first speed. The Clean-tech produces a sound of 60.7 dBA in this mode.

Fan Speed Clean-tech (dBA)
Speed 1 (Min)53.6 dBA
Speed 2 (Max)60.7 dBA

Overall, I believe this air purifier is a bit too loud and that engineers from Clean-tech could do a better job in optimizing the motor for noise.


Operating Costs – Power Usage Test & Filter Price

Clean-tech is a 36W air purifier. However, the UV-C light alone is 24W, meaning that this air purifier uses a low-power fan.

Clean-tech Air Purifier - Inside the Unit
The Clean-tech air purifier motor. Photo: / Milan Antonic

I have never seen an air purifier with such powerful UV-C light; even one of the most popular air purifiers on the market, the GermGuardian AC4825, uses a UV-C light that’s less than 5W.

What I think about the Clean-tech is that a slightly more powerful motor would contribute to better performance and higher CADR. The ability to run at more speeds would also be a great addition.

Monthly Power Cost – Comparison

Comparison of the monthly power cost at maximum speed between the Clean-tech and some of its competitors.

If you were to leave the Clean-tech running at maximum speed for one month, 24 hours a day, your electricity bill would increase by approximately $3.65. However, this scenario is almost impossible, as you can’t leave Clean-tech running at maximum speed for 24 hours a day.

The device switches off in this mode after only 2 hours and switches to standby mode.

Fan Speed Clean-tech (W + $/month)
Standby0.8W ($0.07)
Speed 1 (Min)37.6W ($3.3)
Speed 2 (Max)41.6W ($3.65)

As Clean-tech still doesn’t offer a replacement filter and UV-C light, I can’t say for sure what the maintenance costs are and whether or not the Clean-tech is affordable to maintain.

Filtration Technology

The most significant difference between Clean-tech and other air purifiers on the market is the difference in the filtration process. The Clean-tech air purifier uses two-stage filtration, consisting of H11 HEPA filters and UV-C light. Clean-tech focuses on UV-C filtration as the primary filtration stage. 

The UV-C light is a medical-grade light installed in the unit, just above the H11 HEPA filter. Also unique to Clean-tech is the idea that the device kills bacteria and viruses instead of trapping them in the HEPA filter, as many other air purifiers do.

H11 HEPA filter

The first stage of filtration in the Clean-tech air purifier is the H11 HEPA filter. Basically, its primary purpose is to make the job of UV-C light easier by capturing larger particles and transferring only the smaller ones to UV-C light.

Clean-tech Air Purifier - HEPA Filter
A HEPA filter. Photo: / Milan Antonic

The H11 HEPA filter is several times less efficient than the True HEPA filters we see in many air purifier brands. The HEPA filter is not washable; it should be replaced when it gets dirty. The filter replacement period is on average 6-12 months. It all depends on the air quality in the room where you use the air purifier and how well you maintain the filter.

If you want to know the difference between various HEPA filters, I strongly recommend reading my detailed explanation of what an HEPA filter is.

Clean-tech Air Purifier - HEPA Filter Cover
A bottom cover. Photo: / Milan Antonic

Do not be alarmed if the plastic on the inside of the HEPA filter turns yellow over time; this is purely due to exposure to a large amount of UV-C light and does not affect the filtration in any way.

Currently, I have not found a place where you can buy a replacement HEPA filter for the Clean-tech, so it is essential to consider this before purchasing the device.

UV-C light

As I mentioned earlier, UV-C filtering makes Clean-tech innovative and different from most other air purifiers on the market. UV-C light falls in the light spectrum just before visible light. UV-C light is commonly used in medical environments and kills bacteria and allergens on a molecular level instead of trapping them in the filter.

Clean-tech Air Purifier - Disassembled
UV-C light. Photo: / Milan Antonic

Clean-tech uses a 24W 254nm UV-C germicidal lamp that is mounted inside the device. The UV-C lamp occupies about 75% of the surface of the device; the rest is the HEPA filter and motor.

The UV-C light reflects off the mirror surface and can sanitize even more bacteria and viruses from the air. For every compliment, the UV-C (24W) light intensity is several times greater than that of competing air purifiers

In addition to the Clean-tech, I had the opportunity to test the GermGuardian AC4825, which uses incomparably weaker UV-C light with an output of only 5W.

Clean-tech Air Purifier - Bottom
Screws for the cover on the bottom of the device. Photo: / Milan Antonic

The UV-C light is challenging to change and requires a particular procedure, but the good thing is that this light lasts on average 2 years (18,000 hours), meaning it does not need to be changed very often.

UV-C light reflects on the floor of the device, but according to Clean-tech, it is not harmful and can in no way harm you.


Clean-tech is similar to many other air purifiers on the market. There is nothing that stands out when it comes to aesthetics. It is entirely painted white, with air inlets and an H11 filter on the underside all the way down.

In terms of size, in general, the device is very small, mobile, and easy to carry. However, it would be good to have handles or slots for carrying.

Clean-tech Air Purifier - Positioned on the Desk
The Clean-tech air purifier is on the office desk. Photo: / Milan Antonic

There is a HEPA filter cover at the bottom, but the difference with other similar devices is that this cover is screwed on, requiring a slightly more complicated procedure to remove it.

I don’t like the Clean-tech build quality; I think a device in this price range should be much better and of higher quality. The plastic is not top quality. The device’s interior is fragile; after some time, something has broken off in the device, and I hear the knocking when I pick it up and try to move it.

Device Control

Clean-tech does not have an advanced option, which makes controlling the device altogether easier. The device is controlled by a button on the top. The button is used to switch the device on or off and to switch fan speed.

The button responds to pressure (it does not seem like a touch button). Sometimes it does not respond correctly, so I suggest pressing it harder. To the left and right of the button are indicators to show which fan speed is currently active.

Clean-tech Air Purifier - Control Buttons
A control button. Photo: / Milan Antonic

When you switch on MAX mode, the machine will run at maximum speed for 2 hours and then automatically switch to standby mode. I do not like the fact that the device cannot be left at full speed all the time. However, if the mode is in MIN mode, the air purifier will run until you turn it off. The difference is that MIN mode is 50% weaker than MAX mode.

It’s a pity that Clean-tech doesn’t have advanced options such as auto mode, smart sensors, or a timer, which would greatly help.


Clean-tech is designed so that air enters through the vents on the underside. The air is then filtered through an H11 HEPA filter and a UV-C filtration process. Finally, clean, filtered air exits through the grilles at the top of the unit.

Size and Dimensions

The air purifier weighs 9 lb. The dimensions of the device are 7.87 x 7.87 x 16.5 inches.

What’s in the box?

When you buy the device, you get an air purifier with Clean technology, a power cord, a pre-installed UV-C lamp, an H11 HEPA filter, and a user manual.

The Clean-tech requires no special preparation; the device is ready to go. All you need to do is place it in the desired location, at least 20 cm away from other objects, plug it in, and switch it on.

However, as the Clean-tech draws air from below, it is essential to place the device on a hard surface and never on a carpet or other similar material.

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Customer Support and Warranty

Suppose you have been following the Clean-tech campaign on Indiegogo. In that case, you might have noticed a lot of dissatisfied users and criticism on the Clean-tech customer support page. That’s also why I always test customer support, so I did it again this time. I contacted the Clean-tech team several times by email, and I can confirm the slowness in response, which took 10 days to respond to a message.

Clean-tech Air Purifier - UV-C Light At The Bottom
Front view. Photo: / Milan Antonic

Clean-tech has a 12-month warranty, and you can return the product within 7 days, but only if you buy it directly from the Clean-tech website or via Indiegogo. If you buy the product on Amazon, Amazon’s return policy applies. Therefore, if you decide to buy a Clean-tech air purifier, my strong recommendation is to do it on Amazon.

FAQ on Clean-tech Air Purifier

Is the HEPA filter in the Clean-tech air purifier washable?

No, the HEPA filter should be replaced between 6 and 12 months on average.

How often should the UV-C light be replaced?

On average, the UV-C light should be replaced every two years.

What is the Clean-tech warranty?

Clean-tech has a 12-month warranty.

Does Clean-tech produce ozone?

Clean-tech uses a UV-C light that does not produce ozone, which means there is no ozone production.

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