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UV Devices Could Keep Indoor Air Free of Viruses

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Re: UV Devices Could Keep Indoor Air Free of Viruses

#51

Post by nerdawson »

DoingIsLearning wrote: post #34
a1371 wrote: post #4

When you talk to Indoor Air Quality (IAQ) most are uncomfortable with UV. Reason being that while you can get rid of viruses, you can also create volatile compounds. Our homes' air is like a soup of natural and synthetic chemicals. From your flooring wear to your decor off-gassing to cooking, there are elements in your air that may be safe as they are, but they can completely change when they hit something volatile l…

When you mention decor off-gasing, is this the whole thing about off-gasing fire retardant chemical treatments? Or did you mean another source in household stuff?

I think pressed / laminated sheet materials like particleboard are one of the biggest sources of offgassing in many homes.

Re: UV Devices Could Keep Indoor Air Free of Viruses

#52

Post by DoingIsLearning »

nerdawson wrote: post #51
DoingIsLearning wrote: post #34

Earlier quoted context omitted.

When you mention decor off-gasing, is this the whole thing about off-gasing fire retardant chemical treatments? Or did you mean another source in household stuff?

I think pressed / laminated sheet materials like particleboard are one of the biggest sources of offgassing in many homes.

So it's mostly volatile stuff coming out of the glues in particleboard?

Re: UV Devices Could Keep Indoor Air Free of Viruses

#53

Post by highwaylights »

raverbashing wrote: post #29
clumsysmurf wrote: post #16

Earlier quoted context omitted.

Interesting, does this also apply to far-UVC (222nm)? Its not surprising that UV would be a catalyst in some undesirable scenario. I'm thinking about toxic residues left by cigarette smoking reacting with household surfaces. Research suggests that rooms facing the sun (with blinds open) have less bacteria and viruses because it is a disinfectant. I would have to imagine in many homes, UV is somewhat pervasive anyhow.…

Yeah While glass blocks some of UV light I'm not sure it would be a big problem. Especially if it's constrained to a tube, for example Couple it with an activated carbon filter and it should be good (also a HEPA filter of course)

You can buy HEPA units that have a strip of UV diodes internally after the filter. They’re not overly expensive units. The idea being that the air will pass through:

Charcoal (activated carbon) -> HEPA media -> UV light.

There are some arguments that the UV stage might lower air quality by causing particulates to adhere to room surfaces due to electrostatic charge (i.e. particulate counts would drop rapidly due to particles sticking to walls and furniture, but would then drop off as the charge dissipates and return to room air after the filter is off). I’m not sure how relevant this is - as the filter would catch the particles on the next cycle so I guess it would depend on if the unit is running 24/7 or only some of the time.

Mine failed under warranty and wasn’t replaced with a UV unit due to concerns about Ozone.

Re: UV Devices Could Keep Indoor Air Free of Viruses

#54

Post by highwaylights »

slimsag wrote: post #15
wesapien wrote: post #9

Earlier quoted context omitted.

My uncle has ozone generators in his home. One of them is industrial strength and he only runs it when he is leaving his house for awhile. Does ozone produce by products? I vaguely recall hospitals used ozone to clean n95 masks.

Ozone is very dangerous. The EPA concluded it poses serious health risks back in 2013 (causes asthma and respiratory harm, short and long term exposure is linked to likely early death, and even linked to cardiovascular problems.) Cleaning air is simple; you don't need to look to obscure Ozone/UV devices. For gasses/VOCs, you need a carbon filter. The larger the filter and more air that moves past it, the better. You…

This.

Ventilation is critical, lest you get other issues such as mould which is a whole other set of problems in itself.

IKEA do some very good value devices. The Fornuftigs are nice, but quite weak. The Starkvind smart purifiers are better. They’re explicitly not HEPA and aim for less dense media / higher cycles, and they produce generally similar results at lower costs.

(There are some poorly informed reviews online that give a bad review because they’re not marketed as true HEPA filters, but this misses the point of cleaning the air you breathe rather than the air inside the unit. There was a post that corrected these reviews on HN some time back, will try to dig out and update).

LINK: https://news.ycombinator.com/item?id=31812259

Re: UV Devices Could Keep Indoor Air Free of Viruses

#55

Post by notafraudster »

ciconia wrote: post #39

I find the obsession with having a sterile environment ridiculous. Our bodies themselves are teeming with microbes and viruses, actually our bodies contain more of them than our own human cells. They play an important role in our digestive system, as well as our metabolism and also keeping our immune system on its guard. What needs to be done is not to eliminate those actors, but rather to make our bodies resilient t…

From a cost-benefit perspective, it feels like most of the things we did to get sterile environments paid off with massive, dramatic drops in mortality and morbidity at every age group and the costs have been a bit of regulatory burden for business and maybe increases in childhood allergies which are likely to be nonfatal and low morbidity? That's a pretty good tradeoff. Even if you think obesity is a phenomenon entirely caused by gut biome and not food, it's still going to be a huge economic positive.

Re: UV Devices Could Keep Indoor Air Free of Viruses

#56

Post by refurb »

goodpoint wrote: post #50
ciconia wrote: post #39

I find the obsession with having a sterile environment ridiculous. Our bodies themselves are teeming with microbes and viruses, actually our bodies contain more of them than our own human cells. They play an important role in our digestive system, as well as our metabolism and also keeping our immune system on its guard. What needs to be done is not to eliminate those actors, but rather to make our bodies resilient t…

> make our bodies resilient to potentiel pathogens How? Magic?

Immune system? Some might call it magic.

Re: UV Devices Could Keep Indoor Air Free of Viruses

#57

Post by parkingrift »

ciconia wrote: post #39

I find the obsession with having a sterile environment ridiculous. Our bodies themselves are teeming with microbes and viruses, actually our bodies contain more of them than our own human cells. They play an important role in our digestive system, as well as our metabolism and also keeping our immune system on its guard. What needs to be done is not to eliminate those actors, but rather to make our bodies resilient t…

> What needs to be done is not to eliminate those actors, but rather to make our bodies resilient to potentiel pathogens.

If we expose ourselves to these pathogens and wait a few thousand years we might naturally evolve to be resilient.

…otherwise I have no idea what you’re proposing here. You can’t just decide to be resilient. Pathogens kill people. They don’t die because they lacked willpower.

Re: UV Devices Could Keep Indoor Air Free of Viruses

#58

Post by jansan »

a1371 wrote: post #4

When you talk to Indoor Air Quality (IAQ) most are uncomfortable with UV. Reason being that while you can get rid of viruses, you can also create volatile compounds. Our homes' air is like a soup of natural and synthetic chemicals. From your flooring wear to your decor off-gassing to cooking, there are elements in your air that may be safe as they are, but they can completely change when they hit something volatile l…

I have a cheap UV-C lamp that I purchased from ebay. Aside from the danger to your skin and eyes, after running for a few minutes there will be a distinct ozone smell in the room. Once I keept it on for a few hours in a small room (windows and door closed, no people inside). The ozone smell was still there after one week. So at least the lamp that I own would not be suitable for killing virii in indoor environments, unless there is an easy way to convert the ozone back to O2.

Re: UV Devices Could Keep Indoor Air Free of Viruses

#59

Post by dtgriscom »

sberder wrote: post #35

I haven't seen one of the main arguments against UV efficiency in the context of an HVAC system. Most common UV solutions simply cannot clean at the speed the air goes through the systems in most buildings. When you have to maintain 6 air changes per hour, the UV solutions are simply not manageable. There are other limitations but that's the main issue as far as I can tell talking to facility managers.

A room, its occupants and its HVAC is a steady state system, with people emitting virus particles and the HVAC system removing it. The goal is to have the HVAC system remove virus particles quickly enough so that the average particle density is low. You don't need the air coming out of the vent to be completely aseptic; you just need to remove a significant amount of the virus on each pass.

Re: UV Devices Could Keep Indoor Air Free of Viruses

#60

Post by [deleted] »

Fomite wrote: post #37
abdullahkhalids wrote: post #10

If this is used inside homes and offices, how does one train their immune system, which requires constant low level exposure to foreign entities?

Your immune system is challenged thousands upon thousands of times a day. Clean air won't leave you compromised.

[deleted]
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