Would buying an air purifier be helpful for Home/Apt?

I've had some mold in my shower and even my car this past year (long story, but I HIGHLY suspect my car mechanic caused it, by leaving a nasty greasy residue on my fibers...).

I also have allergies and eczema. They causes itchy rashes (though usually very manageable by avoiding certain things and using topic Desonide cream). Had some bacterial infection too not too long ago (probably from me scratching my eczema too much and having it get infected).

Question: Would buying an air purifier be helpful?

1.) With germ-killing capacity (ultraviolet germicide)
2.) With "harmful particle"-killing capacity (i.e., anti-mold spore HEPA filters)

I'm mainly asking because:

a.) The "good ones" cost $100+ (which, for me, feels like "a lot"....at least, right now it is) b.) Wondering if there are any cons/negatives I don't know about, such as ...maybe the ultra-violet thing easily catches fire or something? ..Or some other crazy hazard. c.) Would you have to buy like a bunch of these to really be effective if you have lots of rooms to your house/apartment/condo, in which case that'd be hundreds of dollars. Anyone have experience with one of these air purifying machines? Worth it for you? Any risks/dangers? Thanks! ETA: Saw this Time article, which says to avoid the ionizing air purifiers, because they cause health problems. http://time.com/4773089/air-purifier/ Last edited: Answers and Replies Related General Discussion News on Phys.org phinds Science Advisor Gold Member 2019 Award I've had a good Honeywell for several years and it's good for taking dust out of the air. It has a "germ" mode and an "alergen" mode but I have no idea if they are effective. I don't think$100 is particularly high for a good one. In fact, it's really on the low end.

berkeman and russ_watters
Honeywell - Just came back from a late night Walmart shopping trip. Saw that they have Honey Wells, Thera-something, and an ionizing purifier.

They Honeywell machines cost $159 and$179 from what I saw. I haven't read online reviews to know if these are considered the "good ones," but they were the most expensive. I saw a $59 and$89 one too.

BUT, I read that what you want is the ones with a HEPA filter. I saw reload packets (2-pack bundle) of the filters, which cost something like $29.99. I've had a good Honeywell for several years and it's good for taking dust out of the air. It has a "germ" mode and an "alergen" mode but I have no idea if they are effective. I don't think$100 is particularly high for a good one. In fact, it's really on the low end.
Do you reload filters more than 2x a year, phinds?

I spent $40/tube (3x/year...for a total of$120) on Desonide cream last year for my allergy rashes, so that alone might cover the cost of the filters!!

Tom.G
Science Advisor
The thing about mold (and insects like silverfish, cockroaches, etc), is they all need a relatively high humidity, generally 60% or higher. A frequent recommendation is ideally below 50%. Many people are uncomfortable below 55%, and below that you may get static electricity sparks after walking on a carpet.

My wife and I live a few blocks from the Pacific Ocean with high humidity, especially at night. For decades we have used a portable Dehumidifier (about $160 at Home Depot) rated for 70 pints per day in 700 to 800 sq.ft. apartments. We typically run it on automatic for 8 to 10 hours during the day, maintaining around 52 - 55% Relative Humidity, and shut it off at night. The humidity in the morning is usually in the 65 - 75% range and the dehumidifier runs for a few hours and then starts cycling to maintain the set-point. The first week or two you have one it will likely run almost continuously to dry out the furniture, carpet, and clothing. Here in California with the high Electricity prices ($0.20 - $0.25 per kWH), it costs about$25 - $40 dollars a month to operate. In the Summer we have to run the air conditioner too because there is a lot of waste heat from the dehumidifier. There is also an exhaust fan in the bathroom that gets turned on when showering, other than that it isn't used much because it draws in the damp outside air. Since we don't use the kitchen stove much, we also partially sealed the range hood exhaust with Aluminium foil. If you have forced air heating/cooling be sure to change the filter every two or three months, and use a filter rated for pollen and allergen blocking. They cost about 10% more than the cheap ones (the local Walmart carries them here). A possible substitute for the Desonide if you are having a fungal problem is Boric Acid (Sodium Borate Decahydrate, it's sold as Ant and Roach powder in hardware stores). Be sure to get 99% or better purity without any other active ingredients, you don't want insecticide in it. You can sprinkle the powder in shoes, gloves, etc to keep the fungus under control; also in nooks and crannies in the bathroom to kill any mold. I use a concentrated solution in a spray bottle on my feet, and on my fingers as needed. Probably not a good idea to use it on large areas though. Mix some in warm water and shake until no more will dissolve then add water until it does dissolve. It tends to clog the spray nozzle so occassional maintenance is required. Just don't use it on broken skin, in your ears or eyes. Boric Acid is fairly safe, in weaker concentration it used to be the go-to solution for eyewash. (see: https://en.wikipedia.org/wiki/Borax) Cheers, Tom p.s. I just checked the log for the dehumidifier, 229 kWH over 1525 Hours, or 112kWH per month. This place is sealed pretty well though. My wife and I live a few blocks from the Pacific Ocean with high humidity, especially at night. For decades we have used a portable Dehumidifier (about$160 at Home Depot) rated for 70 pints per day in 700 to 800 sq.ft. apartments. We typically run it on automatic for 8 to 10 hours during the day, maintaining around 52 - 55% Relative Humidity, and shut it off at night. The humidity in the morning is usually in the 65 - 75% range and the dehumidifier runs for a few hours and then starts cycling to maintain the set-point. The first week or two you have one it will likely run almost continuously to dry out the furniture, carpet, and clothing. Here in California with the high Electricity prices ($0.20 -$0.25 per kWH), it costs about $25 -$40 dollars a month to operate. In the Summer we have to run the air conditioner too because there is a lot of waste heat from the dehumidifier. There is also an exhaust fan in the bathroom that gets turned on when showering, other than that it isn't used much because it draws in the damp outside air. Since we don't use the kitchen stove much, we also partially sealed the range hood exhaust with Aluminium foil.
Was that a Frigidaire dehumidifier? This Forbes (March 2018) article that rates the best ones lists a Frigidaire machine that removes up to 70 pints:

https://www.forbes.com/sites/forbes-finds/2018/03/05/the-best-dehumidifier/#17a12cf49aea
A possible substitute for the Desonide if you are having a fungal problem is Boric Acid (Sodium Borate Decahydrate, it's sold as Ant and Roach powder in hardware stores). Be sure to get 99% or better purity without any other active ingredients, you don't want insecticide in it. You can sprinkle the powder in shoes, gloves, etc to keep the fungus under control; also in nooks and crannies in the bathroom to kill any mold. I use a concentrated solution in a spray bottle on my feet, and on my fingers as needed. Probably not a good idea to use it on large areas though. Mix some in warm water and shake until no more will dissolve then add water until it does dissolve. It tends to clog the spray nozzle so occassional maintenance is required. Just don't use it on broken skin, in your ears or eyes. Boric Acid is fairly safe, in weaker concentration it used to be the go-to solution for eyewash. (see: https://en.wikipedia.org/wiki/Borax)

Cheers,
Tom
p.s. I just checked the log for the dehumidifier, 229 kWH over 1525 Hours, or 112kWH per month. This place is sealed pretty well though.
In case it wasn't clear, the Desonide cream was for eczema, Tom. Not fungus.

I'll look into Broic Acid, but not sure it sounds like something I'd want to ever use if it's potentially dangerous! lol Appreciate the responses, though!

I realize a dehumidifier + an air purifier will run $300-$400 bucks (not including the replaceable filters and electricity costs). I wish I wasn't so poor! It's not too bad, though, since I'll be starting a summer internship job with pay in two weeks. -Cheers back at you!

phinds
Science Advisor
Gold Member
2019 Award
Do you reload filters more than 2x a year, phinds?
I replaced the main (HEPA) filter the first time the "replace main filter" light came on. Brand new filter and yet the light didn't go off. Haven't replaced it since but I take it out a couple of times a year to see if it's dirty. The pre-filter takes out pretty much all of the dust and dust is the only think I care about. I clean and or replace the pre-filter a couple of times each winter. I don't use the device in the summer because we keep the windows open. You can buy rolls of pre-filter material cheap and cut to size but of course if allergens are your concern that doesn't help much.

I bought a nice model when I moved into a new house that didn't have central air. I ended up stopping use because I couldn't notice any difference and when I had a window open I felt like I was just filtering the outside world.

I bought a nice model when I moved into a new house that didn't have central air. I ended up stopping use because I couldn't notice any difference and when I had a window open I felt like I was just filtering the outside world.
I think w/ houses, you might need two or three machines, Greg. Even if you move the machine around from room-to-room, the constant opening up of doors and/or windows might be too much for them if the area is very large.

I've heard certain house plants can be very good for removing air toxins naturally, as they absorb them. But, they also increase humidity in a home and then that can be a cause for mold. So, it's a catch 22.

I replaced the main (HEPA) filter the first time the "replace main filter" light came on. Brand new filter and yet the light didn't go off. Haven't replaced it since but I take it out a couple of times a year to see if it's dirty. The pre-filter takes out pretty much all of the dust and dust is the only think I care about. I clean and or replace the pre-filter a couple of times each winter. I don't use the device in the summer because we keep the windows open. You can buy rolls of pre-filter material cheap and cut to size but of course if allergens are your concern that doesn't help much.
Aw, I'd have taken the machine back for a refund! The big box stores, such as a Home Depot, Walmart , etc. are pretty good about it. Although, if you caught it 3+ months later, their policy may not allow it. But, if the light was broken, I might wonder if something else was wrong with the machine. Hmmmm.

But, yeah, I think a main filter replacement even 3x each year isn't too bad. It's probably a total of about $50 or so for a lot of machines I've seen. I also care about dust, in addition to air toxins. It's both for me. phinds Science Advisor Gold Member 2019 Award Aw, I'd have taken the machine back for a refund! The big box stores, such as a Home Depot, Walmart , etc. are pretty good about it. Although, if you caught it 3+ months later, their policy may not allow it. But, if the light was broken, I might wonder if something else was wrong with the machine. Hmmmm. But, yeah, I think a main filter replacement even 3x each year isn't too bad. It's probably a total of about$50 or so for a lot of machines I've seen.

I also care about dust, in addition to air toxins. It's both for me.
Well, again, it does a great job taking the dust out so I don't care about the rest. Also it was more like a year before the light went on.

kyphysics
Tom.G
Science Advisor
Was that a Frigidaire dehumidifier?
Yes. Model FAD704DWDA. It's quieter than many others but all electronic controls. Don't count on accuracy of the humidity setting or display, it reads low. For accuracy, I bought a wet-bulb hygrometer from Amazon (less than $15) as the three electronic hygrometers all read differently and the mechanical one is REAL slow to respond. kyphysics I've heard certain house plants can be very good for removing air toxins naturally, as they absorb them. But, they also increase humidity in a home and then that can be a cause for mold. I have a plant in every room. Humidity won't be a problem unless you have a dozen in every room. kyphysics Dr Transport Science Advisor Gold Member$100 for an air purifier, I just paid almost $1000 for a cold-plasma purifier for my house to ensure that all the little critters are killed off (my kid almost died from c-diff earlier this year, so we have justified the expense as a medical necessity).$100 for an air purifier, I just paid almost $1000 for a cold-plasma purifier for my house to ensure that all the little critters are killed off (my kid almost died from c-diff earlier this year, so we have justified the expense as a medical necessity). I've never heard of those things you mention above, but I do hope you're family is better and safe now! And, yes,$1,000 is not that much in that context!!

Yes. Model FAD704DWDA. It's quieter than many others but all electronic controls. Don't count on accuracy of the humidity setting or display, it reads low. For accuracy, I bought a wet-bulb hygrometer from Amazon (less than $15) as the three electronic hygrometers all read differently and the mechanical one is REAL slow to respond. Ha! Inaccurate purifier humidity detector and an inaccurate replacement light. Wish these companies would get their products right! Appreciate the "wet-bulb hygrometer" tip. I'll look into that too. There's also an "old fashioned feel test." You can Google your city's temp and humidity level that day (assuming Weather.com's humidity ratings are correct). Then see how it "feels" on your skin to be outside vs. inside your home. ...Although, humidity and temperatures change throughout the day. I'd have to double-check to see if the major weather websites are accurate within the hour or not. CWatters Science Advisor Homework Helper Gold Member Tip.. instead of buying mould killer sprays for the shower at several £ per bottle we buy cheap unbranded bleach, diluted 50:50 with water in a plant sprayer. Spray regularly even if you don't see any. Ideally just before going to bed so it works over night. Tom.G Science Advisor Tip.. instead of buying mould killer sprays for the shower at several £ per bottle we buy cheap unbranded bleach, diluted 50:50 with water in a plant sprayer. Spray regularly even if you don't see any. Ideally just before going to bed so it works over night. Works fine on tile, grout, glass but attacks most organic materials, like wood, some countertops, paint, etc. I've found a dose of rubbing alcohol kills mold (so does vinegar), and Boric Acid after the alcohol dries keeps mold away. kyphysics Tip.. instead of buying mould killer sprays for the shower at several £ per bottle we buy cheap unbranded bleach, diluted 50:50 with water in a plant sprayer. Spray regularly even if you don't see any. Ideally just before going to bed so it works over night. I've heard that bleach being able to kill mold is a myth (at least, a partial one). I initially used a lot of bleach too, but it didn't seem to work. I heard a mold specialist on YouTube talk about how it only kills the surface mold. You need something that goes deeper. White distilled vinegar (which had acid) will actually break it down and kill it totally from what I've read. Not sure if even that is true, but I've seen this "tip" over and over and also mentions of the bleach-mold-myth enough that my go-to now is distilled white vinegar. Feel free to chime in with corrections as anyone sees fit. I want to learn about this subject for long-term knowledge! (amazing demonstration) Has anyone heard of or used these non-battery, non-cord, and "all natural" dehumidifiers? These are cheap, mini dehumidifiers that work naturally. No electricity needed until you fill up the beads. Then you have to plug it in for natural air re-release. But it can be used over and over again the same way without running on electricity and can last up to 10 years. Amazon: https://www.amazon.com/dp/B000H0XFCS/?tag=pfamazon01-20 The company is Eva Dry. Pretty good reviews. I could see this being a good investment over a$200 dehumidifier. These are only $15. Granted, I might need to buy 5 of them or so, but they are an interesting alternative! No need to throw away the waste into a landfill either. It's all renewable technology. I might need to buy 5 of them or so You are severely underestimating that amount. This stuff actually nothing more than a big bag of desiccant. Not really comparable to any real dehumidifier. Price- and efficiency-wise you would be better of with buying desiccant in bulk and packing them in socks. I've heard that bleach being able to kill mold is a myth Well, most official mold-killers are bleach-based (but at quadruple price, at least), and that's no myth. Indeed, it is killing only on the surface, and if the reason behind that mold is not addressed then it will grow anew. But that is the same for all mold-killers. Last edited: StoneTemplePython and russ_watters You are severely underestimating that amount. This stuff actually nothing more than a big bag of desiccant. Not really comparable to any real dehumidifier. Price- and efficiency-wise you would be better of with buying desiccant in bulk and packing them in socks. Well, most official mold-killers are bleach-based (but at quadruple price, at least), and that's no myth. Indeed, it is killing only on the surface, and if the reason behind that mold is not addressed then it will grow anew. But that is the same for all mold-killers. I was partially thinking the Eva Dry minis might be too small after I posted that message. But, I can see them having some usefulness too, in combination with a compressor dehumidifier. I might look into buying both. Having the Eva Dry mini can be helpful for an isolated "trouble spot" like a bathroom. A regular$200 70-pint type of dehumidifier would be weird to place in a bathroom or even near it. You could also use the mini in a car, an attic, etc. I'm thinking.

***NOTE*** I saw online that silica gel is cancer-causing and there was a warning (thanks to California's Prop 65) on some Eva Dry products (not all) for cancer risks.

re: bleach mold myth

I'll have to look it up again, but from what I recall (I could be wrong), it was only helpful on the top layer of mold. To get all the way "into" it and kill it all off (though not the spores), you can use vinegar, as the acid over time (if left on it) will eat it away. Bleach doesn't seem to get "deep" enough into mold and only kills the top "layer." ...But I'll double-check.

People can Google: "bleach + mold + myth" for more info.

I'll have to look it up again, but from what I recall (I could be wrong), it was only helpful on the top layer of mold.
Just as any other liquid stuff. Borax is a kind of exception since it remains on the surface after drying and so it'll give you a kind of permanent protection, but the price for that is that the surface will be contaminated by that mild poison, of course...
Vinegar - well, we tried that too. Apart from the ineffectiveness the permanent stink was the most noticeable feature...

Again: most official mold-killers are bleach-based (but at quadruple price, at least), and that's no myth.

Tom.G
Science Advisor
If you decide to use bleach, add a drop or so of liquid dishwashing detergent to it. That reduces the surface tension of the liquid and allows more intimate contact with the mold.

Rive
CWatters
Science Advisor
Homework Helper
Gold Member
http://blacktoxicmolds.com/bleach-kill-mold.php

Does Bleach Kill Mold
Bleach kills bacteria and viruses and sanitizes the surfaces it's used on. Bleach also kills mold if it comes into contact with it. The spores and allergens from mold are neutralized as well.

Bleach will kill mold growing on non-porous surfaces like glass, tiles, bathtubs and counter tops. However bleach cannot completely kill mold growing in non-porous materials like drywall and wood. Bleach does not penetrate into these non-porous substances and so only the mold growing above the surface is killed.
Explains why it seems to work fine on everything in my shower (stone, sealant and grout which was sealed with stone sealer).

Wouldn't vinegar attack many stone tiles (eg Travertine which I think is limestone like).

CWatters
Science Advisor
Homework Helper
Gold Member
Not sure this is any help to the OP but...

Here in the UK we tends to build well insulated, badly ventilated houses and wonder why they are stuffy. However increasing ventilation can lead to large heating bills in winter. When we built our current house we decided to fit a MHRV (Mechanical Heat-Recovery Ventilation) system. This provides increased levels of ventilation without greatly increased heating bills. It extracts warm humid air from wet rooms like the kitchen and bathroom and expels it via a heat exchanger. Cold air is drawn in from outside and passed through the heat exchanger, which warms it, then it's ducted into bedrooms and living rooms.

We've been impressed by how much healthier our house feels than previous houses we have lived in. In addition we opted for wood, stone and tile floorings rather than carpet. This and the MHRV system seems to help keep dust levels down. We hardly ever have to dust shelves for example.

I have mild asthma and hay fever and both have been much better since moving into this house. If I was ever to build another house I would put this kind of system high up on the wish list.

The down side is that such systems aren't cheap or easy to retrofit to an existing house but it's not impossible.