I bought an air purifier (HEPA and charcoal filters) which also ionizes the air. This is supposed to further purify it, somehow? I’ve seen mineral lamps that supposedly ionize the air, too. It sounds like woo to me, but googling attempts are showing the actual benefits to be inconclusive.
Is this a made-up woo thing, or is there any real science behind it?
There is a bit of real science behind it, but it’s mostly woo.
If you remember back to the days of CRT style televisions, they always seemed to collect a lot of dust. This is because the charged screen tended to trap the dust through simple electrostatics.
An ionizing air filter does kinda the same thing. It charges up plates which attract dust and pull it out of the air.
The thing is, your TV never even got close to absorbing all of the dust out of your room. If it did, you would have had to clean it every few days or it would have been unwatchable due to the thick layer of dust on it. While a TV did get pretty dusty after several months, it clearly wasn’t happening at a rate which would dramatically (or even noticeably) decrease the amount of dust floating around in the room.
So ionizers do remove some particles out of the air, but not much.
Some ionizers have fans that blow air across the charged plates. Others just have charged plates and rely on air currents to move the dust past the plates. The ones with fans work very poorly. The ones without fans are significantly worse. Not worth the money in either case.
Agreed, the amount of dirt removed is not worth the effort. It’s just for show.
The real problem, though, is that these devices can add ozone to the air. Some used to actually brag about this effect. “That after-storm clean smell.” Ozone is bad. Over time, even ones that don’t produce too much ozone can start producing it as they age. You have no idea if your device does or will eventually produce ozone.
Avoid air ionizers in all forms completely.
I’ve worked at hotels for years and we use something that maintenance refers to as an ionizer for when people smoke in their room and we need to get the smell out. Are we talking about the same thing?
If so, I’d say it kinda works for the purposes we use it for but it takes a really long time and leaves the air in the room with an unpleasant kind of a quality.
This might be the effect I’ve noticed. I’d always described the after effects as a “metallic kind of smell” even though metallic doesn’t absolutely make sense as a description of a smell. People generally find it unpleasant.
This is why the fine for smoking in your room is equal to the cost of the room for one night. You’ve completely fucked the room for at least 24 hours, more like 48 really. If we’re facing another sold out night for the day you checked out, we have no choice but to put someone else in the room and they’ll probably end up demanding that we comp their room for the night.
So, yeah, you’re paying the damned smoking fine.
I recall studies going back to the 70s looking at some ionization level in air and how it affected people’s behavior and self assessments of their mental state. All seemed woo-ish, didn’t see any convincing results.
sounds to me like they are “ozoning” your smoked up hotel room. Ozone is or was commonly used to get smoke and other odors out of permeable objects. i wouldn’t want to sleep in that room either any less than at least 4 solid hours of thorough airing out after ozone treatment
Well, ozone can be good to clear out certain smells. Smoking is one, and the used bookstore i worked at had one, to get rid of that “musty” smell*. But you dont want to sleep or stay for long periods in a room with something that emits significant ozone.
Bah. Have they ever smelled ozone? (Well, Classically… ) It isn’t petrichor. It’s a lot more pungent, and most people don’t consider it pleasant.
I thought petrichor was the smell of dust before it rains…
Several years ago the Sharper Image was aggressively marketing an ionizing air cleaner, the Ionic Breeze, as its flagship product. It was criticized by Consumer Reports–they basically said it just didn’t work, along with other similar machines. Sharper Image lost a libel suit against CR. Sharper Image defended itself in the press noting that they have sold 2 million of the units (the “ten million flies can’t be wrong” argument).
And a big reason why you don’t see Sharper Image stores anymore.
There’s a difference between an “ionizer” which just supposedly ionize the air and contaminants and let them seek out and stick to surfaces in the home which naturally carry the opposite electrical charge, and an electrostatic precipitator, which is based on the same physical principles, but are a much more energetic version of it, with actively charged positive and negative plates.
Basically ionizers are worthless, while precipitators are pretty effective in terms of getting particulates out of the air.
For air purification, sure. But they’re often part of an electronics workstation for electrostatic discharge protection. They seem pretty effective at static control, particularly in non-conductive parts that don’t naturally discharge through contact with a grounded work surface (for instance).
But for overall room-volume air purification? Yeah, ineffective.
If you’re concerned about dust and pollen for allergy sufferers have an electrostatic filter installed in your HVAC system. These things will take a lot of particulates out of the air in your whole house and use only of small wattage. They ususally go in place of the standard filter but may be thicker requiring some sheet metal work.