"Ionization" as an indoor air treatment

Delvo · 8th June 2009, 04:11 PM

What are ionizers in fans & such supposed to do, how are they supposed to do it, and do they really?

casebro · 8th June 2009, 05:36 PM

While there are industrial ionic filters, I doubt if the plug-me-in-at-home types actually accomplish anydamthing.

Lots of woo claims about advances in health though. Baloney.

G O R T · 9th June 2009, 05:31 AM

All ionizers generate ions that attach to particles in the air. The charged particles are then attracted to either the collector in a filter design, or the walls and floor in a cheaper ionizer. Cheap home ionizers do indeed work, but often they do not work very well. Ozone generated is sometimes touted as a clean and fresh smell but is actually harmful.

MRC_Hans · 9th June 2009, 06:56 AM

As GORT (Welcome to the forums GORT) says, one effect is to make dust particles stick somewhere instead of floating around. For this to be effective at all, a replaceable/cleanable filter unit and a fan system is required, because the amount of dust in a normal home is huge.

Another function is that it creates ionized air and ozone. Both are chemically aggressive and will attach to and dismantle certain large molecules and micro-organisms. Unfortunately, the amount of ionized air/ozone needed to do this effectively would be dangerous to your health.

If your ionizing filter does not collect amounts of dust comparable to those picked up by your vaccum-cleaner, it is worthless.

Hans

casebro · 9th June 2009, 08:16 AM

But gee, Hans, aren't you forgetting about all the woo things they are supposed to do for you? Why, having ions in your house will balance your Chakra, make your hair thicker, your cooking taste better, your children smarter, your car shinier, your love live better, detoxify your karma, make your prayer wheel spin faster...

the_smasher · 9th June 2009, 12:05 PM

Probably not what you had in mind, but we use this unit in the glovebox in the the lab.
http://documents.desco.com/PDF/TB-2095.pdf (technical bulletin PDF)
It really helps stop balance drift caused by static charge.

Uncayimmy · 9th June 2009, 12:24 PM

Originally Posted by MRC_Hans

If your ionizing filter does not collect amounts of dust comparable to those picked up by your vaccum-cleaner, it is worthless.

I don't follow.

roger · 9th June 2009, 12:58 PM

Originally Posted by UncaYimmy

I don't follow.

If it is doing less than the vacuum, why not just vacuum?

Ferguson · 9th June 2009, 01:23 PM

My mother bought me an ionic breeze about four years ago, and I've used it since, whenever I clean it (ETA: the 'filter' inside), it's covered with a thick carpet of gray and black dust, so it at least "works" in the sense of taking dust out of your home. Whether it's the most efficient way or lives up to commercial hype, I have no idea.

Ferguson · 9th June 2009, 01:27 PM

Originally Posted by roger

If it is doing less than the vacuum, why not just vacuum?

The ionizer can run 24/7. I don't think a direct comparison makes sense.

Professor Yaffle · 9th June 2009, 01:34 PM

I don't know about any other uses, but there is *some* evidence (ie not enough yet for me to go and buy one) that high output negative ionizers might be useful as a SAD treatment.

LibraryLady · 9th June 2009, 01:55 PM

Having just been diagnosed as allergic to the entire known universe and all the elements therein, my allergist/pulmonologist advised me to get an air purifier at least for my bedroom. He said specifically not to get an ionizer because they "don't do a damn thing." Get only a purifier with a HEPA filter.

I've had one for two nights now. Today I woke up feeling somewhat better.

Uncayimmy · 9th June 2009, 01:56 PM

Originally Posted by roger

If it is doing less than the vacuum, why not just vacuum?

Here's what I'm thinking. Please tell me what I'm missing (using the term "dust" loosely).

* Dust gets into the air in the home from outside (it's especially bad here in Phoenix).

* Dust will settle on surfaces including tables, shelves, TVs, couches as well as the floor.

* Dust is tracked in our shoes. For the most part it is tracked directly on to the floor, be it carpet or whatever.

* Dust comes off our bodies - pet dander comes to mind.

* Pets will transfer it directly to the floor as well as into the air.

* Humans will transfer it directly to furniture and bedding.

* Vibrations on the carpet, furniture and bedding due to ordinary use will kick up the dust into the air.

* Running the vacuum will kick dust up into the air, with the alleged exception of those expensive Orek vacuums.

* Sweeping kicks dust up into the air.

So, assuming an air filter device actually works, why wouldn't I want to use it? Conceivably it could reduce the amount of dust in the air at any given time by catching it before it settles somewhere. It could reduce the amount of dusting required for hard surfaces. It could reduce the amount that settles on softer surfaces, which in turn means less gets kicked up during ordinary use.

Ysidro · 9th June 2009, 01:58 PM

I used to work at a place that sold these damn things. They don't work. HEPA filters are good, but LibraryLady's allergist is correct. The ionizers don't do a damn thing.

The whole marketing scheme is basically "it's natural!" with occasional mentionings of "bonding with unhealthy particles". Mostly it just makes things smell ozone-y. Probably because they're making ozone, even when they say they're not.

Mojo · 9th June 2009, 02:05 PM

Originally Posted by Ysidro

I used to work at a place that sold these damn things. They don't work. HEPA filters are good, but LibraryLady's allergist is correct. The ionizers don't do a damn thing.

Don't they at least give you a slight chance of indoor lightning?

Uncayimmy · 9th June 2009, 02:21 PM

Originally Posted by Mojo

Don't they at least give you a slight chance of indoor lightning?

When I was a kid we had a vacuum that could do that. I was four years old when I learned the meaning of shocking.

jasonpatterson · 9th June 2009, 10:46 PM

If you look at the latest versions of the Ionic Breeze filters, they actually include a UV lamp that breaks down the ozone they make. They advertise the thing as producing 'pure oxygen' as a product... Bah.

Ionizing filters certainly work, if they aren't fraudulent. That is, if the air is moved through filters with a strong electric field, any electrically charged dust will tend to move toward one side or the other, depending on its charge. Most dust is charged, by chance, so it can stick (the same reason it sticks to other electronic devices.) In my last house, my HVAC system had an electrostatic charger on the filter. I got bored and tested it as I figured it didn't do anything at all. I alternated running for a month with the charger on and for a month with the charger off over a six month period and there was a difference between the two.

Cuddles · 10th June 2009, 04:22 AM

Originally Posted by Ferguson

whenever I clean it, it's covered with a thick carpet of gray and black dust, so it at least "works" in the sense of taking dust out of your home.

I could make the same argument about my bookshelves.

Marquis de Carabas · 10th June 2009, 04:31 AM

Originally Posted by Cuddles

I could make the same argument about my bookshelves.

...and then sell them for at least twice their value. You're a genius.

G O R T · 10th June 2009, 05:07 AM

Originally Posted by jasonpatterson

If you look at the latest versions of the Ionic Breeze filters, they actually include a UV lamp that breaks down the ozone they make. They advertise the thing as producing 'pure oxygen' as a product... Bah.

Ionizing filters certainly work, if they aren't fraudulent. That is, if the air is moved through filters with a strong electric field, any electrically charged dust will tend to move toward one side or the other, depending on its charge. Most dust is charged, by chance, so it can stick (the same reason it sticks to other electronic devices.) In my last house, my HVAC system had an electrostatic charger on the filter. I got bored and tested it as I figured it didn't do anything at all. I alternated running for a month with the charger on and for a month with the charger off over a six month period and there was a difference between the two.

The UV lamp is to kill/sterilize microbes, UV lamps actually generate ozone as in a spa ozone generator. Short-path electrostatic systems are also less effective.

There is a huge disparity in central air electrostatic air filter designs. Most are cheap and way too short. The ideal design uses a standard pre-filter for large dust and has some two feet between the emitter and collector. The collector can be parallel plates (bulky and hard to clean) or one or more expanded aluminum filters. This design works quite well and if the fan is left on will remove impressive amounts of fine organic dust that is kicked up into the air.

I have no doubt that HEPA filters do what they say, but their low air flow at typical static pressures mitigates their usefulness by reducing draw and turnover. The cost of replacing them frequently for years also makes them the most expensive option.

Uncayimmy · 10th June 2009, 12:26 PM

Originally Posted by Cuddles

I could make the same argument about my bookshelves.

Or you could give the person the benefit of the doubt and assume that he's smart enough to compare his bookshelves to the device.

roger · 10th June 2009, 12:56 PM

Originally Posted by UncaYimmy

So, assuming an air filter device actually works, why wouldn't I want to use it? Conceivably it could reduce the amount of dust in the air at any given time by catching it before it settles somewhere. It could reduce the amount of dusting required for hard surfaces. It could reduce the amount that settles on softer surfaces, which in turn means less gets kicked up during ordinary use.

It was a bit of a throwaway comment, wasn't it? The idea is if it isn't collecting very much dust, it isn't worth very much. Comparing to a vacuum is just a useful measure, as over time your vaccum is going to tell you approximately how much dust you have in your environment. It doesn't make sense to buy and pay for a device that is only collecting a fraction of that amount.

I have a air system for my wood shop to pull the fines out of the air. It completely filters all of the air in a large room several times an hour. It's so loud you can't hear yourself think. That thing will make a difference in the amount of dust in the air, and reduce vacuuming needs. It is also completely intolerable for a living arrangement.

shadron · 10th June 2009, 01:12 PM

Originally Posted by Ysidro

I used to work at a place that sold these damn things. They don't work. HEPA filters are good, but LibraryLady's allergist is correct. The ionizers don't do a damn thing.

The whole marketing scheme is basically "it's natural!" with occasional mentionings of "bonding with unhealthy particles". Mostly it just makes things smell ozone-y. Probably because they're making ozone, even when they say they're not.

I'll tell you another. I worked for a super-computer manufacturer (oh, maybe 30 years ago) who used bleeding edge very high impedance MOSFET circuitry on their boards. Someone talked one of our production managers into installing an ionization system on the production and test floor to defeat static charges which were believed to be destroying circuitry; Colorado is known for having a very dry, staticy climate. It was there for two months, and during that time production had an large number of component failures. While theions perhaps did siphon off static charge, the mechanism caused an electroststic field such that merely tipping the circuit boards from horizontal to vertical induced a multi-kilovolt differential across the circuitry with currents far to low to actually see a spark, but which ruined the MOSFET chips in droves. Very sad time for the company.

G O R T · 11th June 2009, 03:26 AM

Originally Posted by shadron

Someone talked one of our production managers into installing an ionization system on the production and test floor to defeat static charges which were believed to be destroying circuitry

I had an ionizer 30 years ago, still have it actually.

Since an ionizer charges the air (by definition), it would be really dumb to think it would drain/defeat an existing unknown charge.

Oh well.

AndyD · 11th June 2009, 04:25 AM

I wondered the same thing when one was advertised on Australian TV last year. Then I realised the guy (professor) they had promoting it was the same guy who promoted the Moletech (mtech) Fuel Saver on Today Tonight (I think he wrote a report on it). That fuel saver product has since been banned in WA.

The same professor also insists sunscreen is bad - it contains chemicals apparently - and is also associated with a naturopathic "wellness" clinic. Rightly or wrongly, this was enough information for me to make up my mind about the usefulness of the ioniser in the ad.

shadron · 11th June 2009, 03:28 PM

Originally Posted by G O R T

I had an ionizer 30 years ago, still have it actually.

Since an ionizer charges the air (by definition), it would be really dumb to think it would drain/defeat an existing unknown charge.

Oh well.

I have no complaints about your ionizer, but it is not "really dumb to think it would drain/defeat an existing unknown charge". Perhaps I didn't explain all the setup properly.

Ions in the air make air at least somewhat more conductive than when there are none, theoretically, just as water molecules do. That should drain off static charges, allowing then to neutralize. The method used in this case was to attach wires in the ceiling to a high voltage power supply, and dangle down prods with sharp points (which have the effect of "spraying" the ions around the area. The ground was the metal floor and grid false floor system that computer rooms commonly have. The ions drained off the static charges, but the field created by the ionizer did the job on the electronics. Had it used an ion-gun technology (like your personal ionizer probably does), it likely would not have been a problem.

In hindsight, it was a dumb idea; when someone discovered the field strength with a really sensitive voltmeter setup, everyone else had multiple facepalm experiences. However, this was 30 years ago; even the EE doctorates around the place didn't see it coming.

GreyICE · 11th June 2009, 03:40 PM

Ionizing cleaners work by ionizing the air in an ionization section, then passing it through charged plates. Ionized dust is attracted to the plates, and immediately collects on it. Used with a prefilter, they're pretty damn good at getting dust out of the air. They have great efficiencies and minimal pressure drop.

Downside is they're expensive and big.

Home ones are... nothing.

MRC_Hans · 15th June 2009, 04:13 AM

Originally Posted by UncaYimmy

I don't follow.

Well, obviously: If the dust in the air is not picked up by your ion-filter, it will eventually settle to the floor and be picked up by your vacuum cleaner. So if the filter is to reduce the amount of dust in the air, a considerable part of the total amount of dust must be shifted from the vacuum cleaner to the filter, otherwise we must conclude that the filter makes little or no difference.

Hans

MRC_Hans · 15th June 2009, 04:15 AM

Originally Posted by GreyICE

Ionizing cleaners work by ionizing the air in an ionization section, then passing it through charged plates. Ionized dust is attracted to the plates, and immediately collects on it. Used with a prefilter, they're pretty damn good at getting dust out of the air. They have great efficiencies and minimal pressure drop.

Downside is they're expensive and big.

Home ones are... nothing.

Totally agree. Professional ion filters work and are very effective. They are also the size of a small fridge, and much more expensive. And you have to cleean the collected dust out of them on a regular schedule.

Hans

8th June 2009, 04:11 PM	#1
Delvo Illuminator Join Date: Jul 2008 Location: Harrisburg, Pennsylvania Posts: 3,891	"Ionization" as an indoor air treatment What are ionizers in fans & such supposed to do, how are they supposed to do it, and do they really?

8th June 2009, 05:36 PM	#2
casebro Philosopher Join Date: Jun 2005 Posts: 6,800	While there are industrial ionic filters, I doubt if the plug-me-in-at-home types actually accomplish anydamthing. Lots of woo claims about advances in health though. Baloney.
casebro Philosopher Join Date: Jun 2005 Posts: 6,800	__________________ Please pardon me for having ideas, not facts. Some have called me cynical, but I don't believe them. It's not how many breaths you take. It's how many times you have been breathless that counts.

9th June 2009, 05:31 AM	#3
G O R T Student Join Date: Sep 2008 Posts: 33	All ionizers generate ions that attach to particles in the air. The charged particles are then attracted to either the collector in a filter design, or the walls and floor in a cheaper ionizer. Cheap home ionizers do indeed work, but often they do not work very well. Ozone generated is sometimes touted as a clean and fresh smell but is actually harmful.
G O R T Student Join Date: Sep 2008 Posts: 33

9th June 2009, 06:56 AM	#4
MRC_Hans Penultimate Amazing Join Date: Aug 2002 Location: Whithin earshot of the North Sea Posts: 16,602	As GORT (Welcome to the forums GORT) says, one effect is to make dust particles stick somewhere instead of floating around. For this to be effective at all, a replaceable/cleanable filter unit and a fan system is required, because the amount of dust in a normal home is huge. Another function is that it creates ionized air and ozone. Both are chemically aggressive and will attach to and dismantle certain large molecules and micro-organisms. Unfortunately, the amount of ionized air/ozone needed to do this effectively would be dangerous to your health. If your ionizing filter does not collect amounts of dust comparable to those picked up by your vaccum-cleaner, it is worthless. Hans
	__________________ Don't. Just don't.

9th June 2009, 08:16 AM	#5
casebro Philosopher Join Date: Jun 2005 Posts: 6,800	But gee, Hans, aren't you forgetting about all the woo things they are supposed to do for you? Why, having ions in your house will balance your Chakra, make your hair thicker, your cooking taste better, your children smarter, your car shinier, your love live better, detoxify your karma, make your prayer wheel spin faster...
casebro Philosopher Join Date: Jun 2005 Posts: 6,800	__________________ Please pardon me for having ideas, not facts. Some have called me cynical, but I don't believe them. It's not how many breaths you take. It's how many times you have been breathless that counts.

9th June 2009, 12:05 PM	#6
the_smasher Scholar Join Date: Jan 2008 Posts: 73	Probably not what you had in mind, but we use this unit in the glovebox in the the lab. http://documents.desco.com/PDF/TB-2095.pdf (technical bulletin PDF) It really helps stop balance drift caused by static charge.
the_smasher Scholar Join Date: Jan 2008 Posts: 73	Last edited by the_smasher; 9th June 2009 at 12:07 PM.

9th June 2009, 12:24 PM	#7
Uncayimmy Banned Join Date: Oct 2008 Posts: 7,485	Originally Posted by MRC_Hans If your ionizing filter does not collect amounts of dust comparable to those picked up by your vaccum-cleaner, it is worthless. I don't follow.
Uncayimmy Banned Join Date: Oct 2008 Posts: 7,485

9th June 2009, 12:58 PM	#8
roger Penultimate Amazing Join Date: May 2002 Location: Mountain View, CA Posts: 11,021	Originally Posted by UncaYimmy I don't follow. If it is doing less than the vacuum, why not just vacuum?
	__________________ May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view. May your mountains rise into and above the clouds. - Edward Abbey Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you, and the storms their energy, while cares will drop off like autumn leaves. - John Muir

9th June 2009, 01:23 PM	#9
Ferguson Muse Join Date: May 2009 Location: Lansing, MI Posts: 837	My mother bought me an ionic breeze about four years ago, and I've used it since, whenever I clean it (ETA: the 'filter' inside), it's covered with a thick carpet of gray and black dust, so it at least "works" in the sense of taking dust out of your home. Whether it's the most efficient way or lives up to commercial hype, I have no idea.

9th June 2009, 01:27 PM	#10
Ferguson Muse Join Date: May 2009 Location: Lansing, MI Posts: 837	Originally Posted by roger If it is doing less than the vacuum, why not just vacuum? The ionizer can run 24/7. I don't think a direct comparison makes sense.

9th June 2009, 01:34 PM	#11
Professor Yaffle Butterbeans and Breadcrumbs Join Date: Jan 2007 Location: Emily's shop Posts: 15,359	I don't know about any other uses, but there is some evidence (ie not enough yet for me to go and buy one) that high output negative ionizers might be useful as a SAD treatment.
	__________________ I think you'll find it's a little bit more complicated than that. My blog "Well I think I've made it abundantly clear in this thread I have no idea what I'm talking about..." - truethat

9th June 2009, 01:55 PM	#12
LibraryLady ...but not JUST a LibraryLady Join Date: Sep 2004 Location: Building a house in the common ground Posts: 13,081	Having just been diagnosed as allergic to the entire known universe and all the elements therein, my allergist/pulmonologist advised me to get an air purifier at least for my bedroom. He said specifically not to get an ionizer because they "don't do a damn thing." Get only a purifier with a HEPA filter. I've had one for two nights now. Today I woke up feeling somewhat better.
	__________________ What would Hüsker Dü? I am still not a political person, but I am proud that Richard’s and my name is on a court case that can help reinforce the love, the commitment, the fairness, and the family that so many people, black or white, young or old, gay or straight, seek in life. I support the freedom to marry for all. That’s what Loving, and loving, are all about. Mildred Loving Last edited by LibraryLady; 9th June 2009 at 01:57 PM.

9th June 2009, 01:56 PM	#13
Uncayimmy Banned Join Date: Oct 2008 Posts: 7,485	Originally Posted by roger If it is doing less than the vacuum, why not just vacuum? Here's what I'm thinking. Please tell me what I'm missing (using the term "dust" loosely). * Dust gets into the air in the home from outside (it's especially bad here in Phoenix). * Dust will settle on surfaces including tables, shelves, TVs, couches as well as the floor. * Dust is tracked in our shoes. For the most part it is tracked directly on to the floor, be it carpet or whatever. * Dust comes off our bodies - pet dander comes to mind. * Pets will transfer it directly to the floor as well as into the air. * Humans will transfer it directly to furniture and bedding. * Vibrations on the carpet, furniture and bedding due to ordinary use will kick up the dust into the air. * Running the vacuum will kick dust up into the air, with the alleged exception of those expensive Orek vacuums. * Sweeping kicks dust up into the air. So, assuming an air filter device actually works, why wouldn't I want to use it? Conceivably it could reduce the amount of dust in the air at any given time by catching it before it settles somewhere. It could reduce the amount of dusting required for hard surfaces. It could reduce the amount that settles on softer surfaces, which in turn means less gets kicked up during ordinary use.
Uncayimmy Banned Join Date: Oct 2008 Posts: 7,485

9th June 2009, 01:58 PM	#14
Ysidro I'm watching you Join Date: Oct 2006 Posts: 5,334	I used to work at a place that sold these damn things. They don't work. HEPA filters are good, but LibraryLady's allergist is correct. The ionizers don't do a damn thing. The whole marketing scheme is basically "it's natural!" with occasional mentionings of "bonding with unhealthy particles". Mostly it just makes things smell ozone-y. Probably because they're making ozone, even when they say they're not.
Ysidro I'm watching you Join Date: Oct 2006 Posts: 5,334	__________________ This is a sig file. Does anyone even read this stuff?

9th June 2009, 02:05 PM	#15
Mojo Mostly harmless Join Date: Jul 2004 Location: Nor Flanden Posts: 22,102	Originally Posted by Ysidro I used to work at a place that sold these damn things. They don't work. HEPA filters are good, but LibraryLady's allergist is correct. The ionizers don't do a damn thing. Don't they at least give you a slight chance of indoor lightning?
	__________________ "You got to use your brain." - McKinley Morganfield "The poor mystic homeopaths feel like petted house-cats thrown at high flood on the breaking ice." - Leon Trotsky

9th June 2009, 02:21 PM	#16
Uncayimmy Banned Join Date: Oct 2008 Posts: 7,485	Originally Posted by Mojo Don't they at least give you a slight chance of indoor lightning? When I was a kid we had a vacuum that could do that. I was four years old when I learned the meaning of shocking.
Uncayimmy Banned Join Date: Oct 2008 Posts: 7,485

9th June 2009, 10:46 PM	#17
jasonpatterson Philanthropic Misanthrope Join Date: Apr 2009 Location: Space, The Final Frontier Posts: 2,185	If you look at the latest versions of the Ionic Breeze filters, they actually include a UV lamp that breaks down the ozone they make. They advertise the thing as producing 'pure oxygen' as a product... Bah. Ionizing filters certainly work, if they aren't fraudulent. That is, if the air is moved through filters with a strong electric field, any electrically charged dust will tend to move toward one side or the other, depending on its charge. Most dust is charged, by chance, so it can stick (the same reason it sticks to other electronic devices.) In my last house, my HVAC system had an electrostatic charger on the filter. I got bored and tested it as I figured it didn't do anything at all. I alternated running for a month with the charger on and for a month with the charger off over a six month period and there was a difference between the two.
	__________________ Sandra's seen a leprechaun, Eddie touched a troll, Laurie danced with witches once, Charlie found some goblins' gold. Donald heard a mermaid sing, Susie spied an elf, But all the magic I have known I've had to make myself. - Shel Silverstein

10th June 2009, 04:22 AM	#18
Cuddles Decoy Moderator Join Date: Jul 2006 Location: A magical land full of pink fluffy sheeps and bunnies Posts: 16,597	Originally Posted by Ferguson whenever I clean it, it's covered with a thick carpet of gray and black dust, so it at least "works" in the sense of taking dust out of your home. I could make the same argument about my bookshelves.
	__________________ I am not a little teapot.

10th June 2009, 04:31 AM	#19
Marquis de Carabas Penultimate Amazing Join Date: Dec 2002 Location: vuori Posts: 27,106	Originally Posted by Cuddles I could make the same argument about my bookshelves. ...and then sell them for at least twice their value. You're a genius.
	__________________ Jesus ... wasn't he the bloke who turned fish into wine and made the lepers multiply? -KateHL Violence is more acceptable than incest. I have been told to keep this in mind.

10th June 2009, 05:07 AM	#20
G O R T Student Join Date: Sep 2008 Posts: 33	Originally Posted by jasonpatterson If you look at the latest versions of the Ionic Breeze filters, they actually include a UV lamp that breaks down the ozone they make. They advertise the thing as producing 'pure oxygen' as a product... Bah. Ionizing filters certainly work, if they aren't fraudulent. That is, if the air is moved through filters with a strong electric field, any electrically charged dust will tend to move toward one side or the other, depending on its charge. Most dust is charged, by chance, so it can stick (the same reason it sticks to other electronic devices.) In my last house, my HVAC system had an electrostatic charger on the filter. I got bored and tested it as I figured it didn't do anything at all. I alternated running for a month with the charger on and for a month with the charger off over a six month period and there was a difference between the two. The UV lamp is to kill/sterilize microbes, UV lamps actually generate ozone as in a spa ozone generator. Short-path electrostatic systems are also less effective. There is a huge disparity in central air electrostatic air filter designs. Most are cheap and way too short. The ideal design uses a standard pre-filter for large dust and has some two feet between the emitter and collector. The collector can be parallel plates (bulky and hard to clean) or one or more expanded aluminum filters. This design works quite well and if the fan is left on will remove impressive amounts of fine organic dust that is kicked up into the air. I have no doubt that HEPA filters do what they say, but their low air flow at typical static pressures mitigates their usefulness by reducing draw and turnover. The cost of replacing them frequently for years also makes them the most expensive option.
G O R T Student Join Date: Sep 2008 Posts: 33

10th June 2009, 12:26 PM	#21
Uncayimmy Banned Join Date: Oct 2008 Posts: 7,485	Originally Posted by Cuddles I could make the same argument about my bookshelves. Or you could give the person the benefit of the doubt and assume that he's smart enough to compare his bookshelves to the device.
Uncayimmy Banned Join Date: Oct 2008 Posts: 7,485

10th June 2009, 12:56 PM	#22
roger Penultimate Amazing Join Date: May 2002 Location: Mountain View, CA Posts: 11,021	Originally Posted by UncaYimmy So, assuming an air filter device actually works, why wouldn't I want to use it? Conceivably it could reduce the amount of dust in the air at any given time by catching it before it settles somewhere. It could reduce the amount of dusting required for hard surfaces. It could reduce the amount that settles on softer surfaces, which in turn means less gets kicked up during ordinary use. It was a bit of a throwaway comment, wasn't it? The idea is if it isn't collecting very much dust, it isn't worth very much. Comparing to a vacuum is just a useful measure, as over time your vaccum is going to tell you approximately how much dust you have in your environment. It doesn't make sense to buy and pay for a device that is only collecting a fraction of that amount. I have a air system for my wood shop to pull the fines out of the air. It completely filters all of the air in a large room several times an hour. It's so loud you can't hear yourself think. That thing will make a difference in the amount of dust in the air, and reduce vacuuming needs. It is also completely intolerable for a living arrangement.
	__________________ May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view. May your mountains rise into and above the clouds. - Edward Abbey Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you, and the storms their energy, while cares will drop off like autumn leaves. - John Muir

10th June 2009, 01:12 PM	#23
shadron Philosopher Join Date: Sep 2005 Location: Colorado Posts: 5,719	Originally Posted by Ysidro I used to work at a place that sold these damn things. They don't work. HEPA filters are good, but LibraryLady's allergist is correct. The ionizers don't do a damn thing. The whole marketing scheme is basically "it's natural!" with occasional mentionings of "bonding with unhealthy particles". Mostly it just makes things smell ozone-y. Probably because they're making ozone, even when they say they're not. I'll tell you another. I worked for a super-computer manufacturer (oh, maybe 30 years ago) who used bleeding edge very high impedance MOSFET circuitry on their boards. Someone talked one of our production managers into installing an ionization system on the production and test floor to defeat static charges which were believed to be destroying circuitry; Colorado is known for having a very dry, staticy climate. It was there for two months, and during that time production had an large number of component failures. While theions perhaps did siphon off static charge, the mechanism caused an electroststic field such that merely tipping the circuit boards from horizontal to vertical induced a multi-kilovolt differential across the circuitry with currents far to low to actually see a spark, but which ruined the MOSFET chips in droves. Very sad time for the company.
	Last edited by shadron; 10th June 2009 at 01:17 PM.

11th June 2009, 03:26 AM	#24
G O R T Student Join Date: Sep 2008 Posts: 33	Originally Posted by shadron Someone talked one of our production managers into installing an ionization system on the production and test floor to defeat static charges which were believed to be destroying circuitry I had an ionizer 30 years ago, still have it actually. Since an ionizer charges the air (by definition), it would be really dumb to think it would drain/defeat an existing unknown charge. Oh well.
G O R T Student Join Date: Sep 2008 Posts: 33

11th June 2009, 04:25 AM	#25
AndyD Muse Join Date: Apr 2008 Posts: 527	I wondered the same thing when one was advertised on Australian TV last year. Then I realised the guy (professor) they had promoting it was the same guy who promoted the Moletech (mtech) Fuel Saver on Today Tonight (I think he wrote a report on it). That fuel saver product has since been banned in WA. The same professor also insists sunscreen is bad - it contains chemicals apparently - and is also associated with a naturopathic "wellness" clinic. Rightly or wrongly, this was enough information for me to make up my mind about the usefulness of the ioniser in the ad.
AndyD Muse Join Date: Apr 2008 Posts: 527	__________________ Australian Vaccination Network (AVN) Perth homeopaths

11th June 2009, 03:28 PM	#26
shadron Philosopher Join Date: Sep 2005 Location: Colorado Posts: 5,719	Originally Posted by G O R T I had an ionizer 30 years ago, still have it actually. Since an ionizer charges the air (by definition), it would be really dumb to think it would drain/defeat an existing unknown charge. Oh well. I have no complaints about your ionizer, but it is not "really dumb to think it would drain/defeat an existing unknown charge". Perhaps I didn't explain all the setup properly. Ions in the air make air at least somewhat more conductive than when there are none, theoretically, just as water molecules do. That should drain off static charges, allowing then to neutralize. The method used in this case was to attach wires in the ceiling to a high voltage power supply, and dangle down prods with sharp points (which have the effect of "spraying" the ions around the area. The ground was the metal floor and grid false floor system that computer rooms commonly have. The ions drained off the static charges, but the field created by the ionizer did the job on the electronics. Had it used an ion-gun technology (like your personal ionizer probably does), it likely would not have been a problem. In hindsight, it was a dumb idea; when someone discovered the field strength with a really sensitive voltmeter setup, everyone else had multiple facepalm experiences. However, this was 30 years ago; even the EE doctorates around the place didn't see it coming.
	Last edited by shadron; 11th June 2009 at 03:34 PM.

11th June 2009, 03:40 PM	#27
GreyICE Guest Join Date: Mar 2008 Posts: 7,173	Ionizing cleaners work by ionizing the air in an ionization section, then passing it through charged plates. Ionized dust is attracted to the plates, and immediately collects on it. Used with a prefilter, they're pretty damn good at getting dust out of the air. They have great efficiencies and minimal pressure drop. Downside is they're expensive and big. Home ones are... nothing.
GreyICE Guest Join Date: Mar 2008 Posts: 7,173	Last edited by GreyICE; 11th June 2009 at 03:41 PM.

15th June 2009, 04:13 AM	#28
MRC_Hans Penultimate Amazing Join Date: Aug 2002 Location: Whithin earshot of the North Sea Posts: 16,602	Originally Posted by UncaYimmy I don't follow. Well, obviously: If the dust in the air is not picked up by your ion-filter, it will eventually settle to the floor and be picked up by your vacuum cleaner. So if the filter is to reduce the amount of dust in the air, a considerable part of the total amount of dust must be shifted from the vacuum cleaner to the filter, otherwise we must conclude that the filter makes little or no difference. Hans
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15th June 2009, 04:15 AM	#29
MRC_Hans Penultimate Amazing Join Date: Aug 2002 Location: Whithin earshot of the North Sea Posts: 16,602	Originally Posted by GreyICE Ionizing cleaners work by ionizing the air in an ionization section, then passing it through charged plates. Ionized dust is attracted to the plates, and immediately collects on it. Used with a prefilter, they're pretty damn good at getting dust out of the air. They have great efficiencies and minimal pressure drop. Downside is they're expensive and big. Home ones are... nothing. Totally agree. Professional ion filters work and are very effective. They are also the size of a small fridge, and much more expensive. And you have to cleean the collected dust out of them on a regular schedule. Hans
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