Today, I am reviewing a highly popular air purifier from Levoit that came on the market in 2021: the Levoit Core 400S.
This mid-sized air purifier sits between the Core 300S and the larger Core 600S, and it comes with the same cylindrical design and smart features such as the VeSync app.
The overall score for the Levoit Core 400S incorporates first-hand data results from our battery of tests, as well as our ratings for customer service, brand transparency and design & UX. Check out the full scorecard below to see the split of categories.
I have tested and compared the U.S. version with the European version in our YouTube channel, and learned that performance varies between the two. You can watch the video below:
As always, we bought both of our Core 400S devices with out own money so we could write an unbiased review, getting to experience the same customer journey you will if you decide to buy it. If you want to support the work we do at HouseFresh, please use the links in the buttons used throughout this page – we will earn a small commission at no extra charge to you.
The pros and cons of the Core 400S
A summary of our top-level findings after testing this air purifier following our methodology.
“A solid option to consider with medium-sized rooms and those who value smart features like app support, auto-mode, and a screen that displays air quality levels in real time.
That said, I still think most people would be better off with the slightly cheaper Vital 200S thanks to its removable pre-filter, but the Core 400S is worthy of consideration, especially if you prefer the cylindrical design”
HouseFresh Founder
& Lead Tester
Looking for some quick-fire facts on the 400S? Here are the key points from my full review.
CONS
PROS
| HouseFresh rating: | ★★★★☆ |
| Time to clean our 728 cubic feet test room (with the device running at top speed): | 22 minutes |
| Air purifier technology: | 3-Stage Filtration (Pre-filter for large particles, main filter for airborne particles, high-efficiency activated carbon filter for odors and gasses) |
| Recommended room size (4.8 air changes per hour): | 378 sq. ft. |
| Clean air delivery rate (CADR): | Dust: 247 CFM Smoke: 244 CFM Pollen: 269 CFM |
| Dimensions (in inches / in cm): | 10.8L x 10.8W x 20.5H inches (27.4L x 27.4W x 52H cm) |
| Weight (in pounds / in kg): | 11.2 lbs (5 kg) |
| Filter life: | 6 months |
| Noise level in decibels (as reported by manufacturer): | Lowest fan speed: 24 dB Highest fan speed: 52dB |
| Electricity consumption in watts (as reported by manufacturer): | Standby mode: 0 watts Highest fan speed: 38 watts |
| Estimated running cost (electricity consumption + official filter replacement): | $157.94 per year |
| Cost per CADR cfm (based on dust CFM as reported by AHAM): | $0.89 |
| Manufacturer’s warranty: | 2 years |
| Country of manufacture: | China |
Design and controls
The 400S might not set the world alight with its appearance but is well-designed with some useful smart functions.
Those who own any of the Levoit Core series will recognize the design of the Core 400S.
Similar to the 300S and the 600S, it uses a cylindrical design which means it is more compact and takes up less floor space than the rectangular designs we see with the Vital series.
While it’s much bigger than the Core 300S, it feels more manageable than the very large 600S, and as it’s less imposing. Personally, I prefer the design of the 400S over the larger 600S.
Like the other devices in the Core series, the filter in the 400S is bonded, so the particle filter and carbon are combined into one filter, with a layer of mesh pre-filter on top.
This means that cleaning the pre-filter will involve taking out the entire filter, which is more cumbersome and may lead you to clean the pre-filter less often.
The 400S comes with an optical air quality sensor that will need regular cleaning with a Q tip.
I much prefer laser particle sensors, as they don’t need cleaning. Plus, they are more accurate than optical sensors. But it is good for the 400S to come with a sensor as it unlocks smart functions.
You get an LED ring on the control panel that changes color depending on the air quality. But unlike the 300S, you also get the particle count on a little screen inside the ring.
On the panel you’ll get a button to adjust the fan speed, sleep mode, auto mode, a button to switch off the lights, a child lock, a timer and a filter replacement indicator.
App connectivity
Those with smart homes will appreciate that you can connect the Core 400S to your phone and your smart home hub.
You can operate the 400S from your phone through the Vesync app, which is the same app that is used across all Levoit smart appliances. Once the app is set up, you can also use Amazon Alexa or Google home to control/access the air purifier.
Through the app, you can do the usual stuff like scheduling routines but you can also change the settings of the auto mode. This is something I wish more air purifiers would allow so you get to decide whether you want auto mode to hit the top fan speed or not.
Usually auto modes don’t hit the top fan speed to reduce noise and energy consumption, but this leads to the air not being cleaned as fast and effectively as it could be.
One thing that is worth noting is that Levoit has been busy rolling out new features for its app that will work across all models.
The tracking history of indoor air quality data is much better than it used to be, with regular intervals graphed out, including what mode the Core 400S was on at the time. I hope to see Levoit continue to improve the app support through regular updates.
All in all, the VeSync app is one of my favorite air purifier apps, but I do find the constant ads annoying. When I go on it, I do it to manage my Levoit devices so I don’t really want to see adverts for other Levoit products. I much prefer a cleaner design that just gives me the tools I need without it turning into a sales pitch to sell me more products.
Filtration technology
For those looking for an air purifier to tackle odors, the 400S is a better choice than the larger 600S due to the option of a Smoke Remover filter with 450 grams of carbon.
Before I take you through what you get with the filter, we first need to talk about the change in marketing Levoit made after Dyson made a complaint to the BBB. When we bought our Core 400S, the filter was labelled as HEPA H13, but in late 2023 Levoit changed their marketing to remove all mentions of HEPA H13 after Dyson complained about the filters not being HEPA H13 certified.
However, after having tested over 100 air purifiers, I can confidently say that you don’t need a HEPA filter to get excellent air cleaning performance, as shown by what we saw when testing the Luggable XL-7 from CleanAirKits with its MERV 13 filters. This can be explained by the fact that high-grade HEPA filters will restrict the air passing through them, which in turn leads to lower airflow compared to low-grade particle filters that can benefit from the air passing through the filter multiple times.
Having said that, I still don’t think it’s okay for Levoit to say one thing publicly across their marketing and then take it all away quietly without any explanation of what happened or any sort of clarification on the grade of their filters.
Anyway, let me tell you about the filter…
The Levoit Core 400S has a cylindrical bonded filter that is larger than what you get with the Core 300S but smaller than the filter in the Core 600S.
As we’ve come to expect from Levoit, you will find that there are multiple options for filters, each with different amounts of carbon.
The Original filter has 240g of carbon. The Pet Allergy and Toxin Absorber filter have 400g of carbon. Finally, the Smoke Remover filter comes with 450g of carbon.
The Levoit Core 400S with the Smoke Remover filter has the highest amount of carbon in the entire Levoit range.
Be aware that even though more activated carbon will be better for dealing with odors and gases, it will also reduce particle removal performance as carbon restricts airflow. So, if you don’t need the extra carbon, you are better off sticking with the original filters as they will save you money and offer higher CADR for removing particles.
It’s super simple to install and replace these filters. All you have to do is twist the body of the purifier, slot in the cylindrical filter with the tabs facing up, and reassemble the unit. Check out our short video below to see just how easy it is.
All new filters come inside a plastic wrapper. Be sure to remove this before installing the filter into the unit.
Air cleaning performance
Our American Core 400S cleared our test room in 24 minutes, whereas our European version needed 30 minutes.
According to our PurpleAir Zen sensor, the U.S. version of the Core 400S needed 24 minutes to achieve PM1 zero in our 728 cubic ft. test room — we estimate a PM1 CADR of 213 cfm.
We were surprised to see that the European version of the 400S was slower, needing 30 minutes so we estimate a PM1 CADR of 198 cfm.
You can see the results of both tests in the chart below:
As you can see from the table, the U.S. Core 400S performs as well as the best devices we have tested when running at top speed.
When comparing against other units in the Levoit range, it becomes clear that the mid-sized Core 400S offers good value for your money:
I reached out to Levoit’s customer support team to confirm whether the two devices were supposed to be the same as I noticed that the same CADR figure was used in the marketing material in Europe and in the U.S.
“The European Core 400S model has been optimized with a focus on noise reduction. Extensive user research revealed that noise levels are a significant consideration for European customers. By optimizing the wattage, we are able to deliver a quieter experience without compromising essential air purification capabilities, ensuring a product that aligns with local expectations for comfort and usability.”
Levoit Customer Support
So it seems that the European version has been designed to be quieter which neatly brings us to the next part of our testing…
Sound levels
In our testing, the sound levels of the U.S. Core 400S ranged from 35.5 dBA to 60.3 dBA, and the European version ranged from 35.5 dBA to 55.9 dBA.
If an air purifier is too loud, you will turn it off eventually. That is why we always measure how much sound each air purifier generates from three (3) feet away.
Be aware our background noise is 35 dBA, so the 400S running at sleep and speed 1 is likely to generate less sound if you could measure it in a silent room.
Sound levels at low fan speeds are very similar but the U.S. version runs louder top speed. Compared to some of the best HEPA retail devices we have tested, the European Core 400S is quietest at top speed, but as expected, it can’t compare with a PC fan air purifier like the Luggable XL-7.
However, you are unlikely to want to run your device at top speed all the time, so we found a fan speed at which the Core 400S generates less than 45 dBA of noise, which is the limit we have set for our quiet performance tests.
Running at speed 2 the European model hits 44.4 dBA and the American version hits 43.2 dBA, so we repeated the particle removal test with both devices running at that sub-45 dBA speed.
The U.S. version running at speed 2 is much closer to other mid-sized devices like the Vital 200S and Winix 5500-2 but can’t compete with much larger CADR devices like the Levoit EverestAir.
But as with most HEPA retail design it can’t compete with PC fan-powered devices like the Luggable XL and AirFanta 3Pro.
Long-term running costs
Running a Core 400S will cost you $144.41 per year, combining energy consumption costs and filter replacement prices.
As always, we used our energy meter to measure how much electricity the 400S uses when running at each fan speed and also while on standby.
As with sound, the difference in energy usage only shows at the top fan speed. If you had to leave your European Core 400S running 24/7, it would cost $26.07 in energy costs for a year and for the U.S. Core 400S it would cost $44.43
Considering you need to replace the filter every six months and that the replacement costs $49.99, you can expect to also spend $99.98 per year on filters.
When combining energy and filter costs, you can expect to pay $126.06 if you buy the European version and $144.41 if you get the U.S. version, due to the slightly higher energy consumption.
There are many generic filters available, starting at $34.99 per filter. We will run performance tests with a range of generic filters for our Patreon supporters.
Bottom line: Is the Levoit Core 400S worth it?
It really depends on the version you get, as the European version and U.S. version are not the same.
The European Core 400S will cost less to run at top speed on a yearly basis, but the U.S. version offers better air cleaning performance at more usable speeds under 45 dBA.
Its size is much easier to live with compared to the Core 600S and Levoit EverestAir, and it requires less floor space than the Vital 200S.
While it lacks the Vital 200S removable pre-filter, the Core 400S still has all the smart functionality and features of the latest series, and I was pleased to see that Levoit has been adding new features to the app.
The OEM filters are fairly priced and thanks to the efficient fan motor, it doesn’t consume as much energy as other mid-sized air purifiers.
Another pro is that its Smoke Remover filter comes packed with the highest amount of pelleted activated carbon in the Levoit Core range, including the much pricier Levoit EverestAir, which has 400 grams of carbon.
For those wanting a cheap air purifier with a good amount of carbon to help remove odors, the Core 400S with the Smoke Remover filter is the best option available under $250. In fact, you will usually find it online at around $180.
This review is a great example of how important first-hand testing is, as the AHAM report available on the EnergyStar website shows one CADR figure for the Levoit Core 400S but our testing shows that there are CADR differences between the U.S. version of this device and the model sold across Europe.
If you appreciate the lengths we go to with our air purifier reviews, be sure to use the links in the buttons. We will get a small affiliate commission at no extra cost to you, and it will help support the work we do here at HouseFresh.
Have you got any questions about the Core 400S that I didn’t answer in my review? Please, drop them in the comments below and I’ll reply as soon as I can.
