I believe it was in the AHAM directory when I first reviewed it (about 3 years ago). Otherwise, I wouldn’t have included that information in the review.

However, it’s Energy Star rated and tested for CADR, which matches what I mentioned in the review: 140 CFM (around 237 m³/h).

I suggest keeping the air purifier on as much as possible, ideally 24/7. This will ensure that the air quality in your rooms is always clean.

I would only turn it off when I’m not at home for a while.

As the manual says, you shouldn’t use it in specific situations.

Hi, you don’t have to be worried, just fully close it on the next cleaning cycle.

I don’t think you made any damage.

The Core 300s has a slightly louder level 1 than Blueair 411, but probably because the Core 300S is meant for slightly larger rooms so it would normally have a larger or more capable fan. At the end of the day the sound is similar to a split indoor AC unit. But overall the noise of the Core 300S (even at level 2 or 3) sounds slightly more pleasant than the Blueair 411. The 411 has a jarring whirl noise, but the Core 300s sounds a little “smoother”. I don’t know if if it’s because the Core 300S fan has a larger diameter or it’s Levoit’s “KeepQuiet” technology.

As for AirSight Plus, so far it seems to report 5–7 for the air quality if the unit is off (even if all day) and then goes down to 1 when it’s on. I would be happy if the reporting is a pretty accurate representation since the particulate sensor is on the back of the purifier. I don’t know if that affects the accuracy since others say it’s better to have it on the side or front of the purifier especially since my Core 300S is situated near the middle of the room, but it’s about 15″ (40cm) away from the wall. It’s now sitting on the floor, but since the Core 300S is “shorter” than the 411 do you think it would be better to elevate the Core 300S by placing it on a desk or similar in a room that is 8ft in height?

Levoit offers setting the sensitivity of the auto mode through the VeSync app. That means if you don’t like how the auto mode works you can modify it through the app by setting it to normal mode, quiet mode, or efficient auto mode (a fully editable mode).

Hi, unfortunately, I haven’t tested the Core 300S yet, but recently, I tested the Core 400S. It uses AirSight Plus technology as well as the Core 300S, and it’s not as 100% accurate, but it is pretty good.

I don’t think there is any difference in performance for Core 300 and Core 300S.

I have a question in particular to the particulate sensor of the Core 300S: Do you think it’s accurate? I noticed that you use a separate particulate tester and I was wondering if you ever put it near the Core 300S and see if both show the same results? I’m thinking a sensor that’s built onto a purifier may not be the best tool since the air surrounding it will be cleaner than the rest of the room which is why I was thinking if maybe you’ve at least tested side-by-side. That way your dedicated particulate tester will be in a level playing field. If the Levoit is at least accurate being where it is, then I will be content.

I ask because air purifiers seems to be notorious for having ‘cheap’ particulate sensors in them and since Levoit advertises this feature (“AirSight Plus”) like it’s supposed to be good, I can’t help but be curious if it lives up to that at least.