Air purifiers?

[less4success]

Does anyone have an informed opinion on in-home air scrubbers purifiers? In our case, one of us has mild asthma, we both have seasonal allergies, we have no pets, and we live in a temperate climate with lots of rain in the winter.

I suspect that they do in fact remove pollutants from the air, but I'm not sure I'd be able to tell (assuming I don't live underwater or on a space station). I'm curious if anyone noticed an impact on allergies or asthma (or anything else) after installing one of these. I'm also wondering how much it actually costs to run one of these (since there are consumable parts, as I understand it).

Given that the web (as viewed through search engines) is a vast sea of useless SEO garbage, I haven't been able to find reputable information on air scrubbers. At this point, I'm fairly skeptical, but I was hoping someone here might have already done similar research.

[Syonyk]

Build your own.  I built a "box of filters" style one, and according to my air quality meters, it does a great job of pulling stuff out of the air.  I'm not sure that it helps a ton with seasonal allergies, but my air quality sensors argue that it's removing an awful lot of crap from the air.  And they're not that expensive to build, either.

At the bottom of https://www.sevarg.net/2021/08/28/temtop-air-quality-sensors/

The filter elements are no longer the same white as the surrounding cardboard - they're grey.  So it's very clearly pulling something out of the air, in addition to what the sensors say.

[SquarePeg]

When I decided to get an air purifier (maybe another term to search with in addition to "scrubber"), I read the NYT Wirecutter article and went with their recommendation. It seemed based on real experience, criteria that I agreed with, and over a decent period of time (a few years).

https://www.nytimes.com/wirecutter/reviews/best-air-purifier/

I considered the "box of filters" type (also known as a Corsi–Rosenthal Box, see here for more info: https://en.wikipedia.org/wiki/Corsi%E2%80%93Rosenthal_Box). But I found the filters aren't all that cheap, and by the time you buy 5 of them, a fan, and the tape you need, you've spent a decent chunk. Also the "store bought" options are smaller and I thought they would be quieter. Finally, looking ahead, I realized that if you want to replace the filters on the box-style filter, you basically have to disassemble and rebuild the whole thing, which seemed like a hassle to me.

(I'm not saying that the box type is bad, or you shouldn't go that route, rather just relating my decision-making and passing along some info.)

[SunnyDays]

There was an episode on Marketplace (a Canadian Consumer's Reports type show) a while back.  Their research and experiments showed that Blue Air Blue Pure 211+ was the most effective for a reasonable price.  I don't know if it translates to real world reduction of allergy symptoms though, but for the price, maybe worth a try.

[ChpBstrd]

I assume you don't have a central heat and air conditioning system, or the obvious solution would be to simply purchase the better-quality filters and change them more often.

[reeshau]

My mother-in-law has some pretty strong seasonal allergies:  like, she loses her voice.  She uses Honeywell air purifiers, and has several running in her house.

We also have them in our house, when she visits.  I also run them overnight in my room and DS's room, as we have some mild symptoms as we get used to Houston's environment.  We find they do make a difference.

A whole-house filter is a good idea too.  But our AC is under-sized, with a single return.  So our AC guy actually recommended us to downgrade our filters, in order to have comfortable levels of humidity.  When it comes time to replace the AC, we will fix that problem, and put in something for the whole house.

[BlueMR2]

A whole-house filter is a good idea too.  But our AC is under-sized, with a single return.  So our AC guy actually recommended us to downgrade our filters, in order to have comfortable levels of humidity.  When it comes time to replace the AC, we will fix that problem, and put in something for the whole house.

That's what I did.  When my A/C failed and the Heating manufacturer was running a crazy good deal I just went ahead and replaced the entire stack and went with full time operation system.  I was a little hesitant because I grew up saving money by opening windows and using a whole house fan.  Not only does this "run like a sealed system" setup help with allergies, but my power bills are even slightly lower than with the whole house fan in conjunction with the old system.  I don't know the SEER on the old system, but it was a 92% efficiency furnace, so not a cheap setup for back then.  This time I went for 96% furnace and the entry level SEER (stepping that up would cost WAY more than I expect to spend on electricity in its lifetime).

[getsorted]

My kid has severe allergies to dust mites as well as asthma. What's helped most for us, in our location, is having a dehumidifier. Dust mites proliferate when it's humid but less so when humidity is kept low. Ours does have an air filter on it as well.

Posting mostly to follow along for recommendations. In the fall, even this isn't really enough. He's on two daily allergy medicines year-round and still needs a daily nasal rinse when we get the one-two punch of ragweed and leaf mold.

[Freedomin5]

There was an episode on Marketplace (a Canadian Consumer's Reports type show) a while back.  Their research and experiments showed that Blue Air Blue Pure 211+ was the most effective for a reasonable price.  I don't know if it translates to real world reduction of allergy symptoms though, but for the price, maybe worth a try.

+1. Give the high level of pollution in China, most expats here in China own multiple Blueair air purifiers (about 1 purifier per room). The filters are HEPA filters.  It cuts the particles in the air by half, according to our air quality monitor. The filters are the most expensive part of the machine, but you don’t have to replace them often, maybe once or twice a year.

And I’ve never heard them referred to as scrubbers. They’re called air purifiers in my circle.

[ysette9]

There was an episode on Marketplace (a Canadian Consumer's Reports type show) a while back.  Their research and experiments showed that Blue Air Blue Pure 211+ was the most effective for a reasonable price.  I don't know if it translates to real world reduction of allergy symptoms though, but for the price, maybe worth a try.

+1. Give the high level of pollution in China, most expats here in China own multiple Blueair air purifiers (about 1 purifier per room). The filters are HEPA filters.  It cuts the particles in the air by half, according to our air quality monitor. The filters are the most expensive part of the machine, but you don’t have to replace them often, maybe once or twice a year.

And I’ve never heard them referred to as scrubbers. They’re called air purifiers in my circle.

I’m glad to see you responding here. As soon as I started reading this thread your name popped into my kind as someone who would likely have experience on the subject.

My observation is that “filter” and “purifier” show up in residential applications and I see “scrubber” in more industrial settings, like factories.

[Syonyk]

But I found the filters aren't all that cheap, and by the time you buy 5 of them, a fan, and the tape you need, you've spent a decent chunk. Also the "store bought" options are smaller and I thought they would be quieter. Finally, looking ahead, I realized that if you want to replace the filters on the box-style filter, you basically have to disassemble and rebuild the whole thing, which seemed like a hassle to me.

... right, those are all the benefits of it! :D  You get to build it, you get a huge filter area, and get to build it again later!

Though as far as noise, a big, slow turning fan does a solid job and isn't that loud for the airflow - or you can get more airflow for the noise.  I'm in my second year on the filters and while they're getting grey, they're clearly still flowing and air coming out is clean per my meters, so I don't see a reason to rebuild it yet.  But it's far more filter media than you'd get with a small cleaner, so I'm not sure the cost difference really matters.  Replace a lot of filters every few years, or a smaller filter every few months.

My office has a small Honeywell filter for a small room, and it does a decent job, I just have to replace the filters every six months or after smoke season.  I wish I had power to run it overnight in conditions like this, though.  It's vile in and out for the first hour. :(

I assume you don't have a central heat and air conditioning system, or the obvious solution would be to simply purchase the better-quality filters and change them more often.

You're limited on most systems in how aggressive a filter you can put in and still get good airflow.  Separate, high-efficiency units are a good option, though I'm seriously considering building a box filter for my furnace, too.  I have the room to do it, and I could put a bunch of MERV 13 filters in to give me better filtering and still enough airflow.

[less4success]

And I’ve never heard them referred to as scrubbers. They’re called air purifiers in my circle.

Updated the thread title since purifiers definitely seems to be the most common term, thanks.

[less4success]

I assume you don't have a central heat and air conditioning system, or the obvious solution would be to simply purchase the better-quality filters and change them more often.

Someone else already addressed this, but our central system can only handle so fine of a filter before it stops working optimally. I change the filters regularly, and they seem only mildly dirty each time.

[less4success]

Thanks, folks! After reading these helpful responses and doing some more research, I think what I really should be focusing on is trying to determine whether or not my house has poor air quality to begin with.

I'm fortunate to live in an area that has good air quality for probably 95% of the year. As for allergens, I'll just make sure to shower and change clothes after e.g. mowing.

It seems clear that an air purifier helps if there are known harmful particulates (e.g. smoke or other air pollution), but it's not clear to me that there is any benefit otherwise (although I certainly wouldn't rule it out!).

[bryan995]

Blueair seems to be the top brand.
We have a blueair 205 in each bedroom. 

High quality white-noise + super build quality + clean air.

[ChpBstrd]

I assume you don't have a central heat and air conditioning system, or the obvious solution would be to simply purchase the better-quality filters and change them more often.

Someone else already addressed this, but our central system can only handle so fine of a filter before it stops working optimally. I change the filters regularly, and they seem only mildly dirty each time.

I had the same problem. My HVAC unit had a built-in slot for a filter on one end of it. Obviously, a high-efficiency filter would stop a lot of airflow if placed right in front of the coils, so instead I reworked a box in my ceiling so that I now have TWO filters which are each BIGGER than the OEM size and now I can use the higher efficiency type without choking everything down.

[getsorted]

I assume you don't have a central heat and air conditioning system, or the obvious solution would be to simply purchase the better-quality filters and change them more often.

Someone else already addressed this, but our central system can only handle so fine of a filter before it stops working optimally. I change the filters regularly, and they seem only mildly dirty each time.

I had the same problem. My HVAC unit had a built-in slot for a filter on one end of it. Obviously, a high-efficiency filter would stop a lot of airflow if placed right in front of the coils, so instead I reworked a box in my ceiling so that I now have TWO filters which are each BIGGER than the OEM size and now I can use the higher efficiency type without choking everything down.

Picture? I'm interested in replicating this.

[BlueMR2]

Make sure that if you do get a new system that they do a good quality thick sealing filter setup.  So many places slap in these things that take the cheap 1" filters you see at all the local stores.  Those filters not only need to be replaced monthly, but do very poor filtering.  You want one of the 5" thick (and more expensive setups).  They last 6 months and have greatly improved filtering.  Be careful when replacing them though, some big box stores have filters that they claim fit, but they are usually 4" and don't properly seal.  Really best to get filters from an actual professional HVAC shop if you want quality.

[lhamo]

A plug for one of my former Fulbright grantees who was dismayed at the cost of Blue Air and other commercial options in China and did testing/R&D on a simple DIY option that produced similar results:

https://smartairfilters.com/en/blog/how-to-make-diy-air-purifier/

We had already bought Alen brand purifiers before they did this hack, but I totally would have gone with their approach if we hadn't.

[FireLane]

I have a Coway HEPA air filter like this one, and I'm generally pleased with it:

https://www.amazon.com/Coway-AP-1512HH-Mighty-Purifier-White/dp/B01728NLRG/

My wife has pretty bad pollen allergies, and she was miserable for a few weeks in early spring and early fall. Putting the air purifier in the room with her does seem to help. On low power it's almost completely silent, on high power it's about as loud as a box fan.

The HEPA filter needs to be replaced every so often, but I've had mine for eighteen months and I haven't had to replace it yet (it has an indicator light that tells you when).

[Psychstache]

I have a Coway HEPA air filter like this one, and I'm generally pleased with it:

https://www.amazon.com/Coway-AP-1512HH-Mighty-Purifier-White/dp/B01728NLRG/

My wife has pretty bad pollen allergies, and she was miserable for a few weeks in early spring and early fall. Putting the air purifier in the room with her does seem to help. On low power it's almost completely silent, on high power it's about as loud as a box fan.

The HEPA filter needs to be replaced every so often, but I've had mine for eighteen months and I haven't had to replace it yet (it has an indicator light that tells you when).

Yeah we have those in our bedrooms. Seems to help.

[lifeisshort123]

We too have the Coway.  I have been told not to waste your money with Dyson.