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Build a do-it-yourself home air purifier for about $25

uofmhealth.org

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Re: Build a do-it-yourself home air purifier for about $25

#231

Post by TeMPOraL »

thewhitetulip wrote: post #209
TeMPOraL wrote: post #187

Earlier quoted context omitted.

I think the key term here is sealed room . And this does not invalidate the study, only helps evaluate the results in context of applying at home or office. I.e. it's still gonna help, but unless you restrict your airflow, not as much as you'd like. Though the same caveat probably applies to all air purifiers too.

>Though the same caveat probably applies to all air purifiers too. So whatever reservations you have against plants as air purifiers apply verbatim to commercial air purifiers. Then why the bias against plants? Funny how you contradicted yourself, not to mention those downvoting me for speaking about plants and yet being enthusiastic about air filters!!

I didn't downvote you and I didn't contradict myself, I only posted a link that urges precise understanding of what the study does and does not show, and to what extent. I have no bias against plants or in favor of commercial air purifiers.

Re: Build a do-it-yourself home air purifier for about $25

#232

Post by zimpenfish »

roel_v wrote: post #190
fyfy18 wrote: post #157

Earlier quoted context omitted.

The CDC has some recommendations on it (yes you can have mold tested to see if it's dangerous): https://www.cdc.gov/mold/stachy.htm I'm not really sure about keeping the humidity below 50% though. The UK and most of Northern Europe has rather high humidity in the winter. It commonly reaches 80-90 RH outside, so you'd have to heat your house to 25c/77F to bring the humidity below 50%.

"The UK and most of Northern Europe has rather high humidity in the winter." Indoors? No, not at all. In the winter the temperature in my house/office is 21-22C and 17 at the lowest at night, and I have to run a humidifier 24/7 to keep the humidity over 30% (otherwise the wooding floors shrink too much).

(anecdata but...)

Currently in the bedroom (thanks Netatmo) it's 17.8° and 69% humidity (with one of the three windows open about 0.5"). That compares to 14.0° and 78% on the balcony. Looking at the graphs, 50% is the lowest indoor humidity over the last month.

Re: Build a do-it-yourself home air purifier for about $25

#233

Post by Moru »

fyfy18 wrote: post #157
electic wrote: post #110

Earlier quoted context omitted.

Woah, this is pretty scary. Thank you for sharing. How did you know it was mold that was in the air? Is there some sort of test kit that you can buy to test for this. Mold is pretty hard to detect because you can't really see it because it typically hides between the walls. Any advice appreciated.

The CDC has some recommendations on it (yes you can have mold tested to see if it's dangerous): https://www.cdc.gov/mold/stachy.htm I'm not really sure about keeping the humidity below 50% though. The UK and most of Northern Europe has rather high humidity in the winter. It commonly reaches 80-90 RH outside, so you'd have to heat your house to 25c/77F to bring the humidity below 50%.

We do have cold winters but that does not mean we have high humidity indoors. Relative humidity means the water contents of the air at 0 degrees is very very low. The higher temperature, the more moisture the air can hold. So when you heat up the air the same amount of water shares a much lower percentage of what the air can hold. In winter the hygrometer is showing 100% moisture outdoors (because ours can't measure below zero degrees C). When that air is heated up indoors, it holds about 20% of what it can hold [0], most likely thanks to warm water taps, us breathing and other moisture sources. This is why many people run their humidifiers so they can at least have 30-40% in winter. Less dry, cracked skin and nose bleed.

[0] https://en.wikipedia.org/wiki/File:Relative_Humidity.png

Re: Build a do-it-yourself home air purifier for about $25

#235

Post by arendtio »

tomohawk wrote: post #214
benbojangles wrote: post #85

I built my own air purifier in 2016, living in London, I was living in a basement and was having breathing problems due to mould. My landlady was gaslighting me at the time, so I built the air purifier. It worked for a while but mould spores cling to the paper filter and eventually grow into the filter material. I think Dyson uses glass fiber filter to stop this problem. My filter helped a lot, but eventually I had s…

In order to take care of mold, you need to clean up what you can using hydrogen peroxide. It will foam up when it contacts mold. Keep applying until this is no foam up. Incidentally, peroxide in a spray bottle is great for cleaning showers and places that get mildew. Always use fresh peroxide. For an air purifier, you need one with a UV light.

Different people suggesting different means against mold here, but in the end, you have to find the root of the problem and eliminate it. Otherwise, you are fighting symptoms.

1. Air filters might reduce the airborne spores, but if you have mold already growing behind some wardrobe you are wasting time.

2. Hydrogen peroxide, chloride, and isopropyl alcohol are all good tools to fight it when you find a place where it grows, but ultimately you have to solve the problem at a deeper level as mold has excellent survival skills (you might clean the wall but the spores in the air infect it again right afterward).

3. In order to eliminate mold, you have to change the environmental conditions. As most living organisms mold requires food and water. The water comes either from inside the wall (that is something only your landlord can fix) or from the air. So try to maintain a low humidity level within your apartment (three times a day. Mold nourishes itself from organic material. Very often that means fabric, wood or wallpapers (yes removing your wallpaper might be a good idea). Since water condenses in cold spots first, those are the place you want to keep looking for (walls next to windows, corners of a room).

Three years ago I had a mold problem in my apartment. Following the above advice, the mold didn't come back (except for a few spots in the shower, but that is kinda difficult to keep dry).

Re: Build a do-it-yourself home air purifier for about $25

#236

Post by pokemongoaway »

thewhitetulip wrote: post #163

Edit: plants do nothing to particle matter in air they can soak up co2, benzene, formaldehyde etc but do ample resesrch before placing plants in your bedroom. Typically snake plants are fine in bedroom as they don't give out CO2 at night. There is no need for an air purifier if you have ample light in your room. Just plant a few indoor plants Peace lily Rubber plant Snake plant Spider plant Aloe vera Money plant Orch…

Not sure why people are claiming your advice is dangerous... I do think plants do something for participate matter too. Just go to Mexico City. Much of the air is terrible and disgusting. Go a couple blocks into the park areas and it seems as good as normal. Sure, this is experiential. But so is the particulate matter you get coated with in the nasty areas of Mexico City (and many Asian cities too for example).

Re: Build a do-it-yourself home air purifier for about $25

#237

Post by morganvachon »

gocartStatue wrote: post #230
mtgx wrote: post #218

Earlier quoted context omitted.

Or a cleaning solution with chloride.

I've heard that vinegar is better for mould, as it leaves the surface rather more "acidy" than aseptic, as chloride does.

In my experience a one-two punch with chloride to kill the mold quickly, followed by a dousing with distilled white vinegar, results in a good short and long term solution for surface mold.

Re: Build a do-it-yourself home air purifier for about $25

#238

Post by 7000skeletons »

lmilcin wrote: post #174
clumsysmurf wrote: post #162

Earlier quoted context omitted.

I was talking to a buddy that does construction work in a pretty wealthy area (Scottsdale, AZ). They are just finishing up a large luxury apartment. Apparently, the contractor let the drywall get soaked while sitting on palettes during monsoon season, and since the roofing wasn't done there were inches of standing water that resulted in black mold. They just drywalled right over it. In the US. In 2018. In a luxury co…

Wow. I am pretty sure they can not only get sued for this but it may be criminal offence.

I'd imagine that's true on both counts, but with these things it's notoriously difficult to prove. You'd have to prove that the contractor knew about the damage, didn't do anything to mitigate it and then knowingly attempted to hide it. All of that is pretty tricky to pull off, given that a home damaged in this way might not show signs of the damage for a good while.

It's why bad actors (such as the ones described above) keep getting away with what they do.

Re: Build a do-it-yourself home air purifier for about $25

#239

Post by sokoloff »

Cthulhu_ wrote: post #203
a012 wrote: post #180

Earlier quoted context omitted.

Dehumidifiers are expensive in power consumption, I don't know which model is more effectively. I'm living in SEA, and get humidity level to 50% 24/7 in my studio equally to double my monthly electricity bill.

I don't know if these are effective, but in my country we have passive dehumidifiers which are basically containers with a load of salt or something like that which draws the moisture out of the air. Good enough to keep caravans in storage mold free. Probably not good enough for e.g. living rooms or actually moist locations, but maybe it scales up. Of course, you'd then need a lot of salt or whatever the stuff is.

Likely anhydrous calcium chloride.

The problem is, once the calcium chloride has absorbed the moisture from the air and is saturated, you have to take it out and dry it to make it effective again. That might be cheaper (in terms of energy) than refrigerant phase-change dehumidification, but it's a lot more labor intensive.

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