I've ran an ozone generator in a house for multiple days, but I went into it with the expectation that it would be uninhabitable for a period of time afterward.

Ozone won't stick around for very long. It is extremely reactive. With windows / doors open and vent fans running it will be cleared out in maybe a few hours max. The first few minutes is definitely overpowering though. You need to have a plan to turn the machine off and ventilate the building that doesn't involve walking through it for longer than you can hold your breath.

For inhabited spaces there are ionizers available optimized to produce negligible amounts of ozone. They produce O2- and N2- ions instead, which are much safer, even beneficial. They help not only with VOCs but dust too unlike ozone which is a neutral molecule.

The confusion with ozone generators is understandable but very unfortunate here.

I chuckled at his indignance over how these things are legal and how easily you can buy them. Chinese will sell you anything to make a buck. It's just business. You can go on Amazon right now and buy a high power 1kW FM transmitter, drop shipped, and set up a flamethrower pirate radio station on a rooftop of your choosing. The cherry on top is they are likely super low quality with crazy spurious emissions.

Of course the FCC will probably be up your ass in half an hour if you tried it; the point is the equipment is readily available in a few clicks, no questions asked.

Don't get me started on the instantly-blind-yourself-and-everyone-else lasers you can buy on eBay (they'll sell you matching counterfeit laser goggles too).

Coincidentally, Technology Connextras (the low-effort side channel for Technology Connections) posted a video this week on ozone generators. He swears by them.

https://www.youtube.com/watch?v=RYKpKMFIdGQ

Sorry to break it to you, but your "recent" thread is 4 years old.

I have a cheap ozone generator I've used for cleaning cars and boxes of used books. Used at the right concentrations and durations, it's magical! Run it outside or in a sealed tote.

But yeah, they'll sell them to just anyone. Electricity and air go in, and ozone (a reactive, toxic chemical) comes out for as long as you leave it plugged in.

The proper way to get rid of smells from a smoker is to wash all of the paintable surfaces with trisodium phosphate, paint all of the walls and ceilings with Kilz primer, and then clean the floors, doors, and woodwork (and everything, windows, etc) with a solvent that removes the tar and resin (or paint them with Kilz too). If there is carpet, remove the carpet and pad and install new carpet. Might need to replace fixtures and furnishings depending on how bad it is.

So yeah, smoking in a house is insanely destructive and takes a long time to actually remove the odor forever.

Also, check all of the drains (including floor drains) to ensure there is water in the trap.

"I can't find any information on how to get rid of lingering ozone"

I'd feel embarrassed if I was their alma mater reading that.

> That reminds me of when I was living right by the BLM protests/CHOP [0] in Seattle and got tear gas in my condo. I had just bought some new coffee beans to try out and when I did the next morning, thought they tasted super "chemical-y" and immediately threw them aways.

This is by far the most Seattle thing I have ever read.

I'm a materials scientist/chemist and the word partition made sense in this context. The VOC/solute is preferentially on surfaces vs floating in the air. This finding doesn't seem super surprising to me given the large surface area of all the stuff in a home.

See https://en.wikipedia.org/wiki/Octanol-water_partition_coeffi... and https://en.wikipedia.org/wiki/Adsorption

In the UK a non-structural wall is called a partition wall -- they're usually plasterboard (I think that is called sheetrock in USA) over wooden studs whilst ordinarily walls are plaster on brick/stone.

I wonder which partitions more VOCs/SOCs, partition or structural walls.

In separation science a partitioning coefficient can be described for an undesirable contaminant, inbetween a solid adsorbent having a certain degree of retention, versus a solvent where it is soluble to its own certain degree, under static equilibrium conditions.

IOW the smoke will have different affinity for different types of furniture, carpets, and window coverings, and when it comes in contact with these they soak it up like a sponge. Because the adsorbent materials are physically like a sponge more often than not, whether on a macro, micro, or molecular level.

The solvent is plain air, but the "solubility" of the raw smoke in air is not a factor because the smoke is not actually dissolved in the solvent (air) at this point, or ever really. The smoke consists of a lot of solid particles that have been forcefully dispersed into the air at uneven concentrations. The smoke itself is not a chemical contaminant that dissolves in the air, it's just dispersed in the air not much differently than an unwanted chemical, for a least a good period of time.

But the solids will eventually settle if they are not purged beforehand. What you're left with after that is then chemical equilibrium.

In a confined enclosure, static equilibrium will eventually be reached between the amount of chemical contaminants dissolved in the air at that temperature, versus the amount adsorbed onto available surfaces. After which no more odor can be released from the furniture once the air is saturated. To really get rid of the smell you're going to have to replace the saturated air with fresh air and one compete air exchange is not usually enough. Also the more efficient air exchange the better, and the fresher the better. If one person smoked one time, or you burned some popcorn and did not let out the smoke right away, that's not much contamination and it's not constant, but it's also not unusual to still smell it a week later when you first walk in from a fresh outdoor air environment. But just don't open the windows when something like a diesel truck is idling outside, new odor could then be coming in in greater quantities than the old odor can escape, one roomful at a time.

You may have grams of "odor" soaked into the carpet along with 100 grams of dirt & dust. But what if the chemical causing the odor only "evaporates" into the air a few milligrams at a time? Because the heavier the liquid, the slower the evaporation and the resulting partitioning coefficient using air as a solvent is such a low number. And it's not too unintuitive to figure that things which are semi-solid like tars or true solids like some pesticides hardly evaporate at all, but can really stink when there's only a few milligrams in the air.

Stuff like that is not going away without a solvent much stronger than air, and also a more concentrated solvent than a gaseous fluid can make contact by the gram much faster than a gram of fresh air can eventually flow by the unwanted material to be removed.

Plain water may not be any better as a solvent at dissolving cooking oils and tars than air is a solvent, but you sure can get a lot more grams into contact with a surface or macro adsorbent quicker compared to air as a gas.

Plain steam dissolves things so much better just from the added heat of the liquid turning it into a stronger solvent, plus so much of the water evaporates so fast at that temperature there is also a purging effect.

Then there's the carpet-cleaning liquids that can improve the partitioning coefficient of water so it will dissolve otherwise insoluble materials without nearly as much heat as steam. Like grams of detergent added to volumes of water to clean a certain area of carpet, or hundreds of grams of water-soluble organic solvent over the same area instead. Or both, simultaneously, or sequentially. Then when you do the math you see how much more effective sequentially is.

Now without doing any carpet cleaning, when you enhance the air exchange rate to do as good a job removing odors as that can accomplish, you are then trying to establish a dynamic equilibrium so odors are being purged outward at an enhanced rate due to increased fresh solvent (air) flow. Kind of like sequential carpet cleaning. One window fan blowing in and one blowing out at opposite ends of the structure can sometimes be more effective than all windows open whether or not using the same fans.

>I wonder what a chemist would have to say about it.

I wouldn't be surprised if people are still wondering :)

Edit: Hopefully they're wondering even more about a lot of things where they didn't know there were equations, actually ;)

As pointed out in another comment HEPA filters don't work well for VOCs (Volatile Organic Compounds), which are gaseous in nature. They're intended to filter particulate matter.

For VOCs you need activated charcoal/carbon filters usually and replace them from time to time.

This kinda makes sense. Water vapor diffuses out through the building materials so why wouldn't VOCs diffuse into those materials?

What you're looking for are not HEPA filters but organic vapor filtering. If you were shopping for a respirator it would be easy but organic vapor extractors I think are a lot more expensive than HEPA filters. I looked in to it when I was doing a couple of oil based coatings for a home renovation project.

> HEPA filters

They won't do anything against VOCs, you need activated charcoal filters

If you are in a temperate climate, just make a habit of keeping a couple if windows open through the day

Thats why ecological buildings use lime and clay for plastering indoor walls. They can absorb a lot of things (water, fumes) and thereby regulate air quality and humidity.

Yes, it probably is. Have you ever heard of the spherical cow?*

Simplifying the surface makes it possible to model the system with equations that can be solved analytically--which gives theorists something to work on. Modeling more complex systems (which often happens, eventually) typically requires lots of computing power and results in a model that doesn't generalize well.

* https://www.sphericalcowblog.com/spherical-cows

They usually do it for avoiding condensation, hence mold. New german buildings are very well insulated (sometimes too much) so you gotta move that condensation humidity.

No it does not need that.

Replication and peer review are required to be very careful about believing small effect sizes that are inconsistent across populations which are so common with papers in biology and medicine measuring the effect of X on Y when it's entirely believable that the study might just be statistical error or cherry picking.

This study is measuring something pretty obvious and it's more akin to you demanding replication and peer review to your bathroom scale. There might be room for some additional studies but the conclusions here "surface areas for VOCs to stick to are much bigger than this simplified model" don't really need to be doubted all that much.