CHRISTINE: This is a dirty secret. Should we even share it?. TIM: Yeah, sure. It’s not a dirty. I mean, it’s kind of cool. HEPA filters actually get more efficient, over time, like, the more air has passed through them, the more stuff they’ve captured, essentially, because as you’re adding dust and other material to the filter, you just creating, more sites for more dust and smoke to stick to it in the future.CHRISTINE: I’m Christine Cyr Clisset.CAIRA: I’m Caira Blackwell.ROSIE: I’m Rosie Guerin and you’re listening to The Wirecutter Show. CHRISTINE: Hey there, it’s Christine. In the very first episode of this podcast, we covered how to keep the air inside your home clean. At the time, there were wildfires across the Western US… and we gave advice on how and when to use air purifiers, and other steps to consider.This summer, there have been wildfires around the world that have put millions of people in the path of smoky, dangerous air. So we thought it’d be a good time to re-air this episode. It’s got tons of great advice and information for ways to make sure the indoor air you breathe is clean and safe.Also, since this episode originally aired, our reporter Tim Heffernan has made a few additions to his guides. For one, he’s added the Coway Airmega Mighty2 as our favorite air purifier… It’s basically an updated version of our original pick. He also now recommends an indoor air quality monitor. We’ll link to both of these along with Tim’s full guide in the show notes.Ok, on with the episode!ROSIE: Christine. Caira. I got to tell you guys, I feel like this entire summer, my phone has been blowing up. Specifically, the Weather Channel app. I’m not. It’s not like I’ve been getting tons of texts. This is I get these alerts. That is like the air quality. The air quality. The air quality. Don’t go outside. It’s it’s it’s alarming. And I’m not entirely sure what to do with them.CHRISTINE: Rosie, the first thing to do is to turn off your notifications. But the second thing is.CAIRA: They just want you to, to click to engage.CHRISTINE: No, but honestly, I do get what you’re saying. And I think, like, you know, it’s hard to know what, you know, if the air is okay to breathe sometimes if you’re if you’re like, if you have kids especially, it can be concerning. And You know, like the last few summers, the wildfire season has been really.CAIRA: Bad, and it feels like it’s only going to get worse or at least continue like this for the years to come, right? Yeah.ROSIE: I’m looking for some guidance on how the air outdoors impacts the air inside my home and what, if anything, I can do about it.CAIRA: Yeah, that’s why today I’m really excited because we’re going to bring in one of the country’s preeminent journalists reporting on air purifiers, a Wirecutter writer who knows a ridiculous amount about them and about how to keep your indoor air clean.CHRISTINE: That’s right. We’re talking with Tim Heffernan, our senior writer who’s focused on air and water quality. Tim is going to talk with us about how to determine the quality of your air, what might be making you sneeze inside, and what to do about everyday air pollution. And he’s also going to talk with us about what to do in emergency situations like wildfires. This is going to be a super informative episode, so you might want to take notes.ROSIE: I’m ready. Got my notepad. Let’s go.CHRISTINE: We’ll take a quick break and be back with Tim Heffernan, our air quality writer. See you in a second.CAIRA: Welcome back to The Wirecutter Show. Tim Heffernan is here. Tim is Wirecutter’s air and water quality reporter He’s been testing air purifiers for 9 years.CHRISTINE: Tim, welcome to the Wirecutter show. TIM: Thank you very much. CHRISTINE: Okay, Tim, before we get into asking all sorts of air quality questions, I know you go really deep on your reporting, and I heard you were, testing water filters. I heard you made rust water and drank it. Can you tell me? Yeah. Can you tell me? I’m sure I’m not getting the details right. TIM: No, you basically are. ROSIE: I hoped that she wasn’t getting the details right. No. TIM: Good. Right. So I was testing a filter made by Lifestraw. You know, they’re often used by, outdoors people, but they also make, pitchers and other things for the home. And Lifestraw filters work differently than most, and they’re sort of like a physical blockage rather than like a chemical reaction with what’s in your water. So in theory, they can also remove things like sediment. That might be in your pipes. Being in New York, I’m used to rust in my pipes, so I thought I should test this thing on rust. And an easy way to make rust, as I learned, is just take steel wool and, put it into some hydrogen peroxide. It just reacts very quickly, and you wind up with pure rust. So I made a bunch of rusty hydrogen peroxide water. I stirred that into about two gallons of tap water, and then just poured this through the filter to see if it actually worked. And it sure looked like it was working. You know, the water that was coming out was perfectly clear, but I thought, I really have to test this myself. So I just drank the water and it was great. You know. CHRISTINE: Like, there was no flavor. Like no off weird flavor or anything? TIM: No. None at. CHRISTINE: All. TIM: It was great. CAIRA: Tim is like our strongest soldier. I good heart, cause you could not catch me doing that. All right. I think first we should really talk about outside air since it’s summer and it’s wildfire season. I want to know how to tell if the outside air quality is good or bad, and what you can do about it. TIM: Right? You know, I’ve looked into indoor air quality monitors, which are a product that’s available but ultimately settled on recommending for most people that they just use an outdoor air quality app. The one that we recommend is EPA’s Air Now. It’s free. EPA maintains testing stations all over the country, so there’s usually one near to you. CHRISTINE: Tim, can you tell me for the for that Air Now app? There’s something called AQI on that. Right. What does that stand for and what does that indicate for people. Yeah. TIM: So so AQI stands for Air Quality index. It’s just a measure of the overall quality of the air outside. And then right, AQI is a combined measure of a of a handful. I want to say it’s 5 or 6 different chemicals, basically compounds that may be in the air and it can be particulate matter and also things like nitrous oxide. But the EPA sets five levels and they’re color coded green yellow up to I think purple that indicate the the general overall quality of the outdoor air. Green and yellow. That tends to be good. Maybe you want to slightly limit your activity in yellow conditions, particularly if you have preexisting condition cardiopulmonary stuff. But as it gets higher, you should start taking precautions. ROSIE: So when do you want to think about wearing a respirator or a mask? Is that really kind of in the in the red zone, especially now what we’re thinking about wildfires, if there are wildfires near where you live? TIM: Yeah, I think once, once, it’s probably in like the orange, red, purple range. That’s that’s just generally good advice. I mean, you can wear them any time you want. Green. Maybe it’s not really doing much because there’s not much for it to be doing given that the air quality is good, but above that, you know, above orange, I would say if you can, if you can do it comfortably, you might as well obviously use a good one like an N95 mask or something. So if you have bad outdoor air quality such as wildfire smoke, it’s probably your best bet to assume that your indoor air quality has gone down and then take steps to, you know, to mitigate that problem. An air purifier is obviously one way to do it. CHRISTINE: So how does the outdoor air quality impact the indoor air quality? I mean, I can guess that it’s not good and that it will seep into your home, but but like, what are the how how is that happening? And what what do you need to think about. TIM: Right. Yeah. I mean, you know homes breathe. They sort of they’re designed to in some ways and certainly modern office buildings, exchanging the air with the outside is very necessary. And so if the air outside is bad. Yeah, that’s going to have some impact within your home as well, So if you have bad outdoor air quality such as wildfire smoke, it’s probably your best bet to assume that your indoor air quality has gone down. And then take steps to mitigate that problem. CHRISTINE: I remember the first place I lived in New York. I didn’t have an air purifier, and I lived near a major road, and the inside of my apartment often was just coated in this, like. Nasty dark grit …it was almost like sand. Right. Yeah. So gross. But I mean, I guess that’s sort of the same thing. If the outdoor air quality isn’t good, then you’re kind of getting a little bit of that stuff inside your home. And also, you know, if you live near a road, if you live near some kind of major source of pollution, this can be an issue. TIM: Yeah, yeah. And so things like that are going to be kind of chronic, right? My first apartment in New York was about 20 yards from the Brooklyn Queens Expressway. So I know that’s great. And well, I remember. ROSIE: Shout out to Bob Moses TIM: We would we would like wipe the windowsill because it would get dirty and it would just smear. It was like a layer of grease, not even grit. Yeah. So yeah, that’s why we basically recommend keeping an eye on what’s going on outside. ROSIE: Tim, does heat impact this? Because I feel like summertime, generally the air quality is worse.TIM: Yeah. I mean, it’s not simply as direct as hotter air is more polluted, but I think it’s more like an overall meteorological thing. When you have an extended heat wave, you know, sort of almost by definition, you have hot air that’s staying in one place for a long time. And so you’re not getting these kind of continuous winds that will clear out the air. And so the pollution that’s going into the air, you know, builds up, and gets worse. You can almost expect that the AQI, the air quality index is going to get worse until that heat wave breaks and a new mass of cleaner air moves in. CAIRA: Okay, so what about really extreme situations like wildfires? Like what can you do to keep your indoor air clean when you have outdoor air? That’s really bad. TIM: You know, we would obviously recommend running an air purifier during those times and especially run it on a higher setting than normal. Just run your air purifier on high for like an hour a day. Maybe when you first get up, the hour before you go to bed, that’ll do a really deep clean of your air. And then the rest of the time, a medium setting or just leaving it on auto will, will most likely keep your air quality actually very good indoors. CHRISTINE: And we’ll talk more about air purifiers in just a second. TIM: Yeah. I mean other things like sealing your windows, and maybe even going so far as to if it’s truly smoky outside, maybe change your clothes, take off your shoes when you come in. Just to reduce the amount of smoke that you’re actually bringing into. CAIRA: Oh, do you put your clothes in, like, a bag or something? Or you can just change them and throw them. TIM: So I think some people will just sort of designate like the, the area inside the front door. Or maybe they come in through the garage and you can just strip them off. I mean, you know, you don’t have to go overboard. I don’t think you need to also immediately hose off. But you just, you know, simple, straightforward things that just limit the amount of stuff you’re actually bringing into the home. And if you have central air, turn it on to where it’s recirculating the indoor air. You’re not drawing an extra fresh air through through the central air system. ROSIE: Yeah. Tim, can I just ask what is even in the air in the case of a wildfire? What? What are the particles? TIM: Right. I mean, it’s a combination of things, but the particles themselves, it’s basically soot, right? It’s whatever has burned. So particles of carbon and other combustion byproducts that are in a physical form, it’s it’s a very fine sort of dust like thing. So that’s the, the component of smoke that you can see. There’s also a huge range of volatile organic compounds basically evaporated chemicals that come from the burning. The good news is, at least according to the EPA, short term exposure to what’s in smoke like that, including these volatile organic compounds, is unlikely to have long term health impacts. Nonetheless, you know, again, take steps to avoid breathing it as much as you can. CAIRA: So what do you do if you don’t have an air purifier like beyond just keeping the windows close and wiping away grit? TIM: Sure. I mean, if you have central air, you can install what are called medium Merv filters in your returns. You know, most return filters, if you look at them, they just kind of look like a loose mesh of somewhat coarse string. A Merv rated filter will look more like typically white felt, but will be opaque to your eyes. And they’re just much more effective at capturing fine particles. The key, of course, is to keep your system running so that you’re pulling the air through these filters kind of continuously, because it’s an iterative process. You know, air is cleaned multiple times. CAIRA: Is this like a DIY air purifier? Is this like when you put the filters on either side of a fan and you run it in type situation? TIM: It’s not. But but those are also they’re effective. And and if that’s what you have, if you happen to have some filters on hand and a box fan that they will fit to, you can make these these box fan filters and they are reasonably effective long term. They’re they’re just large and they’re not particularly beautiful things. But they do work. CAIRA: Got it. ROSIE: And is there ever a time that you would want to wear a mask inside? TIM: I guess I would say if you aren’t able to take other steps or if you know your home is leaky and that outdoor air is is pretty much just coming into your home, then yeah, you know, a mask is an effective way. It’s not the most comfortable thing, but it’s far better than nothing. CHRISTINE: Okay. So if I’m hearing correctly, if you are stuck in the path of wildfire smoke, the first thing you want to do is make sure your home is as sealed up as it can be. If you have an air purifier, definitely run that. I think you had mentioned keeping things very clean and taking off. Smoky clothing, smoky clothes, smoky shoes, just basically cleanliness. Not tracking things inside. TIM: Yeah. I think that doing all those things, you’ve basically you’ve done what you can. CAIRA: Thank you. We’re going to take a quick break. But when we come back we’ll talk about air purifiers, how Tim test them, what he looks for and what you can skip adding to your cart. Be right back. CAIRA: Welcome back to the Wirecutter show. We’re talking with Wirecutter staff writer Tim Heffernan, who covers all things air quality. Before the break, we learned about how to monitor outdoor air quality and how that impacts the air inside. CHRISTINE: And now we’re going to talk more about Inside Air. So, Tim, what are the things inside your home that might be making your inside air dirty? TIM: You yourself are one. Humans and your pets. You know, we we said all kinds of things. So. So we are actually a source. But, you know, we’re talking about things like smoke from candles, smoke from your stove. If you’re, you know, if you’ve burned dinner, the outdoor air has a huge impact, like we discussed. So if it’s pollen season outside, you’re going to have pollen inside, dust in general that’s in the air. And you’re also bringing it in when you come in from the outside, that will be in the air. A lot of it will settle on surfaces, but then you kick it up when you’re walking around, and then things like certain home projects. I’ve been doing a lot of drywall recently. You don’t have to study air purifiers to realize that you’re putting a huge amount of dust in the air when you’re doing that. So, yeah, I mean, those are those are some of the common things. And they’re what? Air purifiers are really very good at, addressing. ROSIE: So how do you know if your indoor air is dirty to the point where it’s going to affect you? TIM: That’s a really tricky question, because the stuff we’re talking about here is basically airborne particles. And they’re so fine that you can’t actually see them. Right. You may be aware, like during pollen season. Right. You’ll you’ll actually be able to see kind of that yellowish dust on things. And that’s like an obvious sign that this pollen is getting into your house. But a lot of times you don’t know. You may have some symptoms, your eyes may get itchy. If you have allergies, they may worsen. Those are all signs. But it it’s one of the tricky things about air quality is a lot of it. It can be bad and you really don’t have an indication that that’s the case, CHRISTINE: right? So it’s kind of like kind of like a just silent, like annoying. Why do I not feel super great inside my home? It could be partially due to the air quality. I know that, you know, my when you you mentioned dust mites and, that’s something I had never even considered before. And then my youngest kid ended up testing positive for a severe dust mite allergy. And we’ll talk about air purifiers in a bit, but. But I have to say that I got an air purifier, and that really, really helped because she was breathing in. Really, a lot of what you’re breathing is in is dust mite poop. And so, you know, I think like what we noticed with her was that her allergy, it presented as really severe eczema. And so I think like that can also be potentially a sign that, you know, if you have some kind of allergy, it can it can actually present maybe in a different way. It might not just be like a sneeze or something. It could be something that’s like manifesting in your skin or, you know, if you have something that. TIM: Yeah, I mean, I think that’s absolutely true, you know. You have something, you know. You know, that seems to be chronic. And there’s not some other obvious cause. It’s worth looking into it, you know, with a with an allergist or something to see if maybe that’s the root cause of this issue. CAIRA: And why you’re trying to dig into that. What tools would you suggest people utilize more, especially if they don’t even have an air purifier? What can they do in their home to alleviate the symptoms? TIM: Yeah, I mean, I think probably the first one is vacuuming using a dust mop. I have I have hard floors in my apartment, and a dust mop is way faster than a vacuum for for getting things like pet hair, general dust, pollen, all this stuff up and off the floor. If you get it up on off the floor and get it out of your house, you know, rinse it down the drain or, you know, shake your mop off into the garbage you’ll eliminate or anyway improve like one potential source right of your indoor air pollution. Slightly more involved, but something that’s worth doing anyway. If your windows are older and they’re not well sealed, you can just put the ceiling, strips around your windows. That’ll reduce the amount of air that’s coming in from the outside and kind of keep if it’s a problem outside, it’ll it’ll reduce the impact on your indoor air. CHRISTINE: So I do have a question about cleaning. It’s about vacuums like I had back in that old apartment. That first apartment I had a vacuum and it wasn’t a very good vacuum. And I don’t think it did a very good job of sort of, you know, every time I would use it, I it felt like there was just dust everywhere in the air. And now I have a Miele, which is not it’s not a HEPA. It doesn’t have a HEPA filter, but it has like a very sealed, like system. So nothing gets out of it. And I’ve noticed that that helps so much more. Like there’s a lot less dust in my home. Is that something that you recommend? Like getting either like a HEPA vacuum or some kind of vacuum that has a really sealed container that it’s not going to let dust out? TIM: Yeah. No, definitely. I also have a Miele I’ve never known. CHRISTINE: I don’t know, I always feel very self-conscious. TIM: But yeah, they’re fantastic, it’s true. I don’t think they’re necessarily true HEPA but that has a very dense, sort of filter material used as the dust bag. And I do think that people will benefit from that. CAIRA: Okay, Tim. So you’ve thrown around this term HEPA I think that we should really just dig into it right now about air purifiers. Like, can you tell us more about how long you’ve been testing them and how exactly do they work? TIM: Right. So, you know, with HEPA filtration, just to start with, HEPA stands for high efficiency particulate air. And it just means the high efficiency means that these are filters that let air pass through very easily. And the particulate air means, really, that they capture all the particles that are in that air down to an extremely small scale nanoscale particles. And I’ve been testing purifiers for Wirecutter for about nine years now. This it’s actually the first guide that I picked up, when I came on board. And it’s been a really interesting journey, if I can use that word. You know, I think a lot of people listening will will also have become sort of more conscious of air quality, you know, over that same nine year span, really beginning in 2017 or 2018, when the wildfires out west suddenly got much more extreme. And then, of course, with the Covid pandemic, you know, indoor air quality suddenly became of paramount importance to people. Yeah. And air purifiers, these HEPA air purifiers that I’ve been reporting on are extremely good at addressing things like smoke and airborne pathogens. CAIRA: So how did you even come up with your testing method? TIM: The test method is actually one that sort of replicates the standard that’s used, to to certify a filter as HEPA. So I use the smoke from matches. If you burn a match or two, you’ll actually produce millions and millions of very, very fine particles that are right around this 0.3 micron, standard that’s used for, for HEPA certification. And it’s used because that’s the most difficult size of particle to capture. So if a filter captures smoke very well, it’s going to capture everything else. Larger stuff like pollen and bacteria all the way down to smaller stuff, including like individual viruses, although they don’t actually typically exist in the air as individual viruses are be. ROSIE: Tim, can you paint me picture here? I know you live in New York. Are you lighting matches all day long in your apartment? Like what’s your match budget? What are we talking about here? And like, is is standing next to the air purifiers and like, what’s the weird. CHRISTINE: Yeah, that’s like, you should outsource that work. That’s like, just like a match lighter. TIM: It’s like, why? No, no, it’s good. I no longer test at home. I did, during the pandemic of necessity, but no, I burned my matches in the office so that everybody gets to enjoy this. TIM: But no. So I test in one of the offices we have there. We can seal it off reasonably well, although we’ve never actually really aimed to have a completely airtight room because homes are not airtight. And we wanted something that kind of reasonably represents real world living conditions. And I do not stay in the room. I burn the matches, and then I quietly exit, and I just let the purifier work and then go back. CHRISTINE: So like you’re burning. How many matches? Like two matches. Three matches. A whole book of matches. TIM: I do five at a time. Okay. I’ve gotten very good at, maximizing the burn. You know. CHRISTINE: That’s really, like, all the way to your finger. Oh, yeah. Yeah. Okay, great. And. And how long does it take an air purifier like these rooms are? They’re in our conference rooms. Right? So it’s like. What? I don’t know, what does that square footage, like 200ft² or something like that? TIM: Yeah, about 200.CHRISTINE: And how long does it take to clear the air? TIM: So, like an initial load of smoke particles in the air can be like a million per cubic foot and in half an hour, you know, a decent purifier can drop that down to just a few thousand. CAIRA: Wow. CHRISTINE: I think it’s something I was always surprised, like at first when I first heard about an air purifier, I thought it was kind of like something magical, like it was just the air went into this box and then it came out clean and but actually an air purifier is essentially just a fan with a filter, right? It’s just a fan with a filter on the front and it’s sucking in air. The fan is sucking in air and pushing it through the filter. TIM: Yeah, yeah. No, I mean, it’s it’s wonderfully simple, right? It’s just a thing that works. You know, there’s essentially nothing to break on it. The filters don’t they don’t run out, you know, the way that, like, something can run out of battery, or run out of gasoline or something. That filter will always be working as long as the air is moving through it. CAIRA: So how often do you really have to change your filter then? If it never runs out, you’re just. TIM: So. CHRISTINE: This is a dirty secret. Should we even share it?. TIM: Yeah, sure. It’s not a dirty. I mean, it’s kind of cool. HEPA filters actually get more efficient, over time, like, the more air has passed through them, the more stuff they’ve captured, essentially, because as you’re adding dust and other material to the filter, you just creating, more sites for more dust and smoke to stick to it in the future. So you don’t typically a purifier will recommend the manufacturer will recommend changing the filter every. Usually eight months or more, typically a year. And you should probably do that because you can get a slight decrease in the air flow as a filter clogs up. But we’ve tested purifiers on filters that ran 24 seven for two years, so twice their lifespan. And there was really no measurable difference in their performance. CAIRA: Every time you describe a HEPA filter, all I can imagine is like Spider-Man’s web. CHRISTINE: Hmhm. CAIRA: And like he just keeps building more webs, the more stuff that’s caught in it. I love that, that’s awesome. ROSIE: I have a question about in terms of, you know, Tim, you’re nine years go by and presumably you’re testing all kinds of different air purifiers is the difference between ones that are recommended and Wirecutter that you’ve written about versus ones you don’t necessarily recommend is a difference. One does the job and one doesn’t. Or what? What’s the nuance there? TIM: Initially when I started, you know, working on this category, we really, really focused on the testing kind of most of all. But. As I did this again and again. You know, we were realizing that really any decent purifier is going to do very, very well because again, it’s it’s very simple physical process. Right? If you move air through that filter, that purifier is going to work. And so over time, actually prioritizing what I call livability factors has become much more important. These things often live in a bedroom or in an office. They might be in the room where you watch TV. So things like how much noise did they make? Most of them have, LED lights on them. Can you turn them off, or at least dim them so that it doesn’t disturb your sleep or your TV watching? Those things have gotten much more important in my eyes, along with obviously really good performance. And so that those are things that I look at much of the time. CHRISTINE: There’s also energy efficiency, right? TIM: Yeah. So energy efficiency is a big one. You know, a purifier can last for a very long time. You know, five years, ten years. There’s very little that can break on it. But they do consume energy. So energy efficiency is really a big one. And also the replacement cost of filters, you know, upkeep cost. We look for purifiers that do a great job. They’re easy to live with and they’re not going to cost you, you know, hundreds of dollars a year to keep them running. CHRISTINE: Oh, I was going to say the I have three air purifiers, the ones that you recommend. And yesterday I actually cleaned them. You can vacuum out there’s like two filters. Right. Or there’s actually three filters. There’s like a front filter that just catches like big hairballs from your cat in my home and dust. And you can vacuum that clean. And then behind that is like this, this black mesh, is it carbon. What is it like? It’s a carbon filter. And then there’s the HEPA filter which looks like fancy like folded paper basically. So we’ve talked about what the HEPA filter is doing. But what is the carbon that middle carbon filter doing. TIM: So you can sort of divide air pollution into two categories particulate stuff. And then broadly speaking, VOCs. These are gases. You know, anything really that you can smell in the air is going to be a volatile organic compound, a VOC. Again those are gases. And a HEPA filter won’t capture them. The black filter you’re talking about. Yeah it’s probably like a nylon or, you know, polypropylene mesh with activated charcoal embedded in it. Those are there to capture these VOCs. And they do do it. The problem is that, unlike the HEPA filter, as you sort of as the carbon filter captures stuff, it does stop work and it’s kind of sacrificial. So it doesn’t last forever the way a HEPA filter does. And also there’s so little of this activated charcoal and most of those filters that in terms of addressing like a serious problem, you know, you’ve just, I don’t know, painted your walls with oil paints, you know, so that it’s you’ve got all these, you know, petroleum chemicals in your air. It’s quickly going to become all used up and really stop doing anything. CHRISTINE: Oh, I totally I’m glad you told me that because I actually thought I was like, saving myself some money and I didn’t replace the the charcoal, the activated charcoal one. When I got new filters last year, and I actually just put the new ones in yesterday thinking like, oh, yes. But they, the old ones were probably doing nothing. TIM: Yeah, I don’t bother with them. I basically pay no attention. CAIRA: So I feel like I’ve seen some air purifiers that advertise different technology than HEPA filtration. CHRISTINE: Ooh, is this time for the m-word? TIM: It is time. We can talk about molekule. CAIRA: Okay, so what is that? TIM: So, Molekule, it’s an air purifier manufacturer. And they had a very successful, you know, very sophisticated and kind of, social media campaign. And it got a lot of interest. ROSIE: I got suckered, they did away. I didn’t buy one, but it ended up in my cart many, many times. CHRISTINE: I mean, like MoMA had it in their shop too. They might still. ROSIE: It’s like very. CHRISTINE: Yeah. Yeah, it’s a very pretty air purifier that is. TIM: We went through a lot of back and forth with them. Initially when I approached them, they were eager to have us tested, and then they got very, very kind of hinky about our testing and then ultimately said, well, you can come to our facilities and we’ll, like, run it in front of you and you can use that testing, which of course we said, no, that’s not going to work. So we just went out and bought, their original purifier and tested it. And as we discovered, it’s the worst air purifier that we have ever tested. ROSIE: Dang drama. TIM: Yeah. You know, essentially what it comes down to, unlike a mechanical level, is it just doesn’t move enough air. And then it has this. At that point, it relied on this, system that they call Peco. It uses ultraviolet light, interacting with titanium dioxide. That’s what’s in white paint. It’s nothing scary. To basically sort of chemically clean the air and neutralize and destroy particles in it. But it’s not a fast process. And again, there just wasn’t enough air moving through the machine. CHRISTINE: Okay, Tim, but I think it’s also important to just state how expensive the molecule is, right? I mean, right now the depending on the model, it’s between like for the small one it’s like 400. But like there are some that are close to a thousand. And you know, the air purifiers we recommend on the site, like the top one, the coal, what you can get that for like 150, right. TIM: Yeah. Yeah. I mean that was one of the things, you know, when we talk about something being the worst that we’ve ever tested, performance per cost comes into it. And on top of not working very well, just like on the face of it, the molecule machines back then and to this day are incredibly expensive relative to extremely high performing HEPA purifiers. CHRISTINE: Okay. All right. So Tim, I, I’m thinking back to my childhood and I do not remember having an air purifier when I was a kid. And now, like with Covid and with so many wildfires happening all the time, I feel like it’s pretty common, like a lot of people have them. When were air purifiers created? Like, is this something that just happened in the in the 80s or 90s, or is this something is this a product that’s been around for a long time. TIM: In terms of like an air purifier in your home? I don’t know exactly when those became a thing. I know they used to sell really bad ones in The Sharper Image. So since the 80s, I guess. ROSIE: I loved the Sharper Image. Also it’s So it’s so it’s so 80s, right? It is. TIM: But HEPA filtration itself, at least in North America, apparently was born in the Manhattan Project. They were searching for a way to remove radiation from the air in the factories. And it doesn’t do that. ROSIE: Spoiler alert it didn’t work. TIM: But they realized, you know, hey, we have invented this high efficiency way of removing particles from the air. And in the postwar years, it’s all applications in industrial settings, in, in medical settings. And, you know, it just seemed like a natural thing, just essentially stick one of those filters on what amounts to a sealed box fan. And now you can purify the air in your home. CAIRA: When it comes to having air purifiers in general, I feel like, I mean, I never knew how to use mine. I feel like I put it in the wrong place. I was never like vacuuming the exterior. I was turning it off to like, save energy and money. How are you supposed to properly use your air purifier? TIM: So in terms of placement, I don’t know. You can sort of think of it the way you might put like a speaker in a room. You want it to sort of maximize the coverage. So, you know, if you can get your purifier roughly towards the middle of one of your walls, keep it a little bit away from the wall. You need that air to be able to, to enter it. Quite. Freely and do not. And I’ve seen this happen a lot. Do not put it under a table or anything like that. That’s kind of like restrict its air flow of coming in and maybe more importantly, going out. You know, you want that cleaned air to be spread around the room. ROSIE: When my air purifiers on high in my room, I and I recognize it because it sounds like the vents that are blowing on you on an airplane like it. It suddenly gets really intense and really loud. And I was thinking about that recently because I think I had heard that airplanes are actually a safe place to be during Covid, to a certain extent because of the HEPA filtration on planes. But how does that work? Does it work in the same way that your unit does at home? TIM: Yeah, I mean, more or less it does. And it’s true, I the last I checked and it has been a while, but this was sort of initial post pandemic. There was a report that said there was not a single known case of a transmission on an airplane. So an airplanes, you know, commercial airlines, they’ve used HEPA filtration, you know, for years and years and years during the pandemic, they increased the air changes per hour, or basically they made the fans cycle the air more frequently. The little vent that you can turn on or off when you sit in a plane that’s blowing the filtered air onto you. So whenever I go on a plane, I just aim it right at my face, like First thing. CHRISTINE: but essentially, though you spoke to this a little bit before, but if you, you know, somebody is sick in your house, somebody has a virus like it will clean the viruses out of your home too, right? So like if you are, you know, you’ve got somebody with a cold and you’re trying not to spread it. Will it help to kind of put the air purifier close to that person who’s sick. CAIRA: Like a barrier? TIM: Yeah. I mean, yes, like at least in terms of will it remove, you know, the viruses or the particles, you know, contain a virus from there? Yeah, it really will. It’ll certainly reduce the load of viruses in the air. Right. Which is, I think sort of more key to transmission. How much virus is there and then how much time you are you exposed to it. So if you have purifiers running it will keep, you know, viruses and bacteria and mold spores and stuff like that at a at a very low level. Of course, if you’re sitting right next to somebody at home and they sneeze, that’s going to get on you or get to you before it gets to the purifier. So in a case like that, it’s not in a sense, doing anything, ROSIE: So you got to just walk around holding it like you’re John Cusack. Boombox. Yeah, yeah, yeah. If you really want. TIM: It to be. No. If you if you think too hard about this stuff, you can make yourself paranoid. ROSIE: And then what do I say to my obstinate friends who refuse to heed your expert advice and don’t want to get an air purifier because they, oh, I don’t know, have a lot of plants? TIM: Plants get talked about quite a bit. I think most of this goes back to a NASA study done in the 80s, where they were looking for ways to keep the air on, like a space station or like a mars mission clean and kind of like a self-sustaining way. It is true that plants in general, in some species in particular, they studied a bunch, are a bit better at removing VOCs. You know, these odors, other gases from the air, but they do it so slowly that to to keep up with. Just like the typical ventilation in a building, apparently you would need to have between 10 and 1000 plants per square meter in your home. So that’s. ROSIE: Like per square meter, one. TIM: Per square foot on the low end. Cool. CHRISTINE: I mean, I like my plant babies, but I can’t have that many of them. Like that’s too many. That’s too many plants inside. CAIRA: Just go live outside at that point. Yeah, forge your kids get plants. TIM: But no, in seriousness, I’ve seen that question come up like, during like wildfire events. And no, absolutely not. I mean, they are simply not capable of keeping up with any kind of like, a critical situation, right? CHRISTINE: I mean, I think you can even see, like, if you haven’t dusted your plants or, you know, you can see that buildup that happens on your plants where it’s just like. ROSIE: They’re not swallowing that grit. CHRISTINE: They’re like, yeah, they’re not they’re not shiny. ROSIE: we’re asking We’re Too much of our plant. CAIRA: So, Tim, before we go, we ask all of our guests one question. What’s something that you bought recently that you really love? TIM: Yeah. You know, I’m doing some home renovations, and I’ve been doing a lot of, like, demolition, pulling down, old walls and moving them. And this place have been put together, just like on the theory that more fasteners and was better. And so there were just hundreds of nails that I had to pull. And I got myself, nail puller from, Knipex. I think it’s called. It’s the Knipex, carpenters and cutting pliers. But basically they’re used as, as nail pullers and you can just take them grab even just like the head of a nail of just the head is barely sticking out. You can just grab it and very easily lever that nail out. And it’s so fast and so much easier than with a hammer. I sort of wanted one of these for a long time, but I was like, do I really need this? But I suddenly did. And yeah, it was it was worth every penny. CHRISTINE: This feels like it should be in a gift guide. I was going to be super sexist and say a Father’s Day guide, but I want it in the Mother’s Day guide because I also have to take nails out all the time. TIM: Oh yeah, it’s super satisfying. And you can. It’s a great wire. I really didn’t mean to bring that up, but it is. It’s a great Wirecutter as well. Like you can use it for methods that. ROSIE: All right. You said the buzz word. Yeah. CAIRA: I love that. CHRISTINE: I love it too. Tim, it’s been great to have you on the show. We want to have you back sometime soon. We want to talk about water and all sorts of other things that you might want to keep clean. CAIRA: Doomsday prepping maybe? TIM: Sounds good. CHRISTINE: And go bags. But seriously, it’s been great having you. And, I feel like I’m going to take some of this and make my air cleaner at home. TIM: Excellent. ROSIE: Thanks for helping us breathe, Tim. CAIRA: Thank you, Tim.TIM: Thank you all. CHRISTINE: Okay. That was a great conversation with him. I feel like I am pretty clear on what I need to do to keep the indoor air quality high. One of my biggest takeaways is that keeping things really clean is a great way to keep your indoor air quality clean. And that means obviously like vacuuming and dusting. And if you’re going to dust, like use something kind of damp because that will keep the dust from or the particles from just kind of going back into the air. CAIRA: Yeah. I really liked how he mentioned that. You have to be mindful about how the outdoor air quality will affect your indoor air quality, to the point where, like, yeah, you should be maybe taking off your clothes from outside as soon as you get in. So you’re not just bringing in the pollution. I really like that. ROSIE: It makes a lot of sense. And actually both of those kind of go hand in hand thinking about all the stuff that you’re bringing in, and then once it’s inside, you’re kicking it out and then you’re breathing it in. For me, the takeaway was about the air purifiers themselves and basically how you kind of have to keep them running. I had been putting them on a few minutes here, a few minutes there, and I think I haven’t been maybe maximizing their efficiency. So that was that was really helpful. CHRISTINE: And now that, you know, you can use your your filter longer, you can just go to town. Just let it. ROSIE: Go. The more you know, you feel me. That’s it from us. Thanks, guys. If you want to find out more about wirecutters coverage on air purifiers, or check out our recommended products yourself, go to nytimes.com, backslash Wirecutter. Or you can find the link in the show notes. CAIRA: Amazing. Thanks. ROSIE: Bye. The Wirecutter Show is executive produced by me, Rosie Guerin, and produced by Abigail Keel. Engineering support from Maddy Masiello and Nick Pittman. Today’s episode was mixed by Katherine Anderson. Original music by Dan Powell, Marion Lozano, Elisheba Ittoop, Rowan Niemisto, Katherine Anderson, and Diane Wong. Cliff Levy is Wirecutter’s deputy publisher and general manager. Ben Frumin is Wirecutter’s editor in chief.CHRISTINE: I’m Christine Cyr Clisset.CAIRA: I’m Caira Blackwell.ROSIE: And I’m Rosie Guerin. Thank you for listening.
Source link