6 ms·

Build an Ioniser in Under $10

124 points by sthottingal 7y ago

joecool1029 7y ago
http://web.archive.org/web/20191229051555/http://amaldev.blog/build-ioniser-in-under-10-dollars/ http://web.archive.org/web/20191229051555/http://amaldev.blo...
userbinator 7y ago
The article mentions BigClive, and his YouTube channel does have a lot of stuff about ionisers, but his site has an article about them too: http://www.bigclive.com/ioniser.htm http://www.bigclive.com/ioniser.htm
Someone1234 7y ago
Just be cautious, while correctly working Air Ionisers are safe, poorly working or designed ones can produce Ozone which is unsafe (particularly over prolonged periods or high exposures). This article has more information (in particular citation 10 used in Adverse health effects): https://en.wikipedia.org/wiki/Air_ioniser#Adverse_health_effects https://en.wikipedia.org/wiki/Air_ioniser#Adverse_health_eff... Personally I don't see the benefit over a HEPA filter on a standard electrical fan, or a commercial unit with a similar design. Yes, replacing filters is annoying/has a cost, but there's no health downsides to the design and it is effective at removing air particulate. Building one requires an off the shelf HEPA filter, an off the shelf fan, and a couple of rubber bands. It isn't "sexy" or technically sophisticated, but it works. Want it improve effectiveness? Increase the surface area/make it bigger/increase the airflow. Let's also consider what both devices (when working correctly) do. An Ioniser gives particulate a charge causing it to be attracted to and stick on surfaces. A HEPA traps particulate within a filter membrane. Or to phase that differently an Ioniser causes the particulate to dust onto every surface within range, causing dirt buildup/stains, dust blooms when disturbs, and people may still contact the air contaminants (since they still exist, now on surface rather than in the air). HEPA allows you to simply remove the particulate from the environment, Ionisers just move it from one location (air) to another (surface).
- seltzered_ 7y ago
  Veritasium had a good video showing the test of ozone being produced by air ionisers: https://youtu.be/ZQ--scjcAZ4?t=663 https://youtu.be/ZQ--scjcAZ4?t=663 (time-linking since the ioniser part was sortof hidden within a video debunking himalayan salt lamps)
  - pergadad 7y ago
    Thank you, really enlightening video. I'm happy I bought a HEPA filter now, rather than an ioniser.
- NickBusey 7y ago
  This is especially ironic in this case, because the entire premise of the article was: "I have always had the issue of dust settling in every week on everything if I open the windows. Cleaning that up every week is a pain." They then proceed to build a device that will, if anything, exacerbate this exact issue.
  - arghwhat 7y ago
    The issue was "I have always had the issue of dust settling in every week on everything if I open the windows." If the dust is airborne, it will naturally spread everywhere before it eventually settles. Making the dust settle early minimizes spread.
- raverbashing 7y ago
  Another way of improving the homemade air purifier is adding an activated carbon filter (read: kitchen extractor hood filter)
- amelius 7y ago
  Can't you collect the dust at a particular location by using an opposite charge?
- AstralStorm 7y ago
  Ozone is actually a useful disinfectant, just make sure to ventilate the room well after treatment. Obviously not the outcome anyone building an ioniser is after.
ncmncm 7y ago
He talks about carbon-fiber stuff to get lots of ionization points, but steel wool works great. You will be able to smell if you are producing ozone, which you don't want unless you like permanent lung damage. The smell is sharp. like around electric sparks. If you get that, the voltage is too high. Just leave off a few voltage stages.
- pbhjpbhj 7y ago
  I love the smell of ozone though (not kidding!). I think it's an association from dicking around with dodgy electric motors (that sparked in a cool way) when I was younger.
  - ncmncm 7y ago
    It's the same reason people like Lisp: it smells of youth.
deleted 7y ago
[deleted]
amluto 7y ago
As the former owner of a biggish HVAC-integrated electrostatic precipitator, these things are not really worthwhile. An ESP needs frequent cleaning to work well, in comparison to a plain old MERV 13 or so filter, which will work for quite a while with no maintenance. An ionizer doesn’t need maintenance, but that’s because it deposits all the gunk nearby. Eww.
m0xte 7y ago
Please don’t build this. There are numerous ways to kill yourself with it. Especially the construction as described.
- hydgu 7y ago
  Could you elaborate a bit more? I am curious from the technical side.
  - m0xte 7y ago
    Lap soldered mains connection (can break off easily). Not double insulated (think small children and fingers). Also the actual ioniser port is usually recessed to avoid accidental contact as it hurts if you touch it. Also lots of hand soldered MLCC caps are high potentials. They like to crack and explode if you do that. They need to be machine soldered really. Edit: also the design doesn’t use proper voltage rated resistors on the output. I haven’t checked the other parts but it’s probably marginal. You’ll get home one day and find your house burned down.
    - chadcmulligan 7y ago
      could do with a fuse to. Those needles connected to active make me uncomfortable, though there's a 10M resistor, I'd have an isolating transformer on the mains - not an engineer though.
      - m0xte 7y ago
        Fuse would be good. Here in UK there’s one in the plug. The 10M resistor will current limit. Or probably flash over here. Isolation transformer is not required if the enclosure is better. It also doesn’t help you if you stick yourself across it somewhere, only helping yourself with respect to ground. If you’re testing it or doing development with it I would use one. But I wouldn’t build it. I used to hang around inside old valve radios when I was a kid. You learn respect for high voltages very quickly.
willis936 7y ago
$10 really means ripping apart and wiring up cheap Chinese consumer electronics. A PCB project is at minimum $100.
jvanderbot 7y ago
All comments seem to recommend a good old filter over an ionizer. Would an ionizer in series with a filter (e.g. in air ducts ) be more effective than a filter itself?
- h2odragon 7y ago
  For some uses. I have to recommend the commercial Honeywell units highly: they're excellent at pulling tobacco smoke and smell out of the air; and yes the area around them will catch all the other dust around too.
fortran77 7y ago
It is not healthy to breathe in high concentrations of ozone. It's difficult to make an "ionizer" that doesn't generate ozone. Also, the health claims of ionizers are dubious. False claims about them (and ozone) bankrupted The Sharper Image https://www.nytimes.com/2008/02/21/business/21sharper.html https://www.nytimes.com/2008/02/21/business/21sharper.html
eeZah7Ux 7y ago
You can buy a ionizer for less than $10 on aliexpress and it might be less electrically dangerous. However - DON'T DO IT. Many ionizers generate ozone which is unhealthy. Also if the goal was merely to combat dust settling on the floor (rather that health), it will only make the problem worse.
- Tempest1981 7y ago
  During crop-burning season in India, when the air is hazardous, would an ionizer + ozone be a net positive? Crop burn pics: https://www.theguardian.com/world/2019/nov/08/indian-farmers-have-no-choice-but-to-burn-stubble-and-break-the-law https://www.theguardian.com/world/2019/nov/08/indian-farmers...
  - pbhjpbhj 7y ago
    Interesting, we banned it in the early 90s in the UK (I used to love watching it). https://www.eurekalert.org/pub_releases/2019-08/imaw-atb080719.php https://www.eurekalert.org/pub_releases/2019-08/imaw-atb0807... suggests there are better alternatives that will yield better returns for the farmers; but I gather some UK farmers want to return to burning as it - in their eyes - reduces weeds and provides ash for tilling in to the soil. It's not a simply equation though, eg https://www.researchgate.net/publication/230319729_The_effects_of_stubble_burning_and_tillage_on_soil_carbon_sequestration_and_crop_productivity_in_Southeastern_Australia https://www.researchgate.net/publication/230319729_The_effec....
  - eeZah7Ux 7y ago
    No: ozone only makes things worse. Plus, a lot of smoke from burning plants has large particles that can be filtered much better with hepa filters
amelius 7y ago
> I these days use LCSC.com to buy all my generic parts. Great selection at a great price. It’s way cheaper than Digikey or Mouser. That's a good one, thanks!
Tempest1981 7y ago
An estimated power use of 4 kWh per year -- only costs 4 Rupees in Mumbai? (around $0.05 USD) That's surprisingly cheap power. The US average is 10x higher. ($0.13/kWh) Still a small cost ($0.52/yr in the US)
tomaszs 7y ago
Epic

124 points by sthottingal 7y ago

http://web.archive.org/web/20191229051555/http://amaldev.blog/build-ioniser-in-under-10-dollars/ http://web.archive.org/web/20191229051555/http://amaldev.blo...

userbinator 7y ago

The article mentions BigClive, and his YouTube channel does have a lot of stuff about ionisers, but his site has an article about them too: http://www.bigclive.com/ioniser.htm http://www.bigclive.com/ioniser.htm

Someone1234 7y ago

Just be cautious, while correctly working Air Ionisers are safe, poorly working or designed ones can produce Ozone which is unsafe (particularly over prolonged periods or high exposures). This article has more information (in particular citation 10 used in Adverse health effects): https://en.wikipedia.org/wiki/Air_ioniser#Adverse_health_effects https://en.wikipedia.org/wiki/Air_ioniser#Adverse_health_eff... Personally I don't see the benefit over a HEPA filter on a standard electrical fan, or a commercial unit with a similar design. Yes, replacing filters is annoying/has a cost, but there's no health downsides to the design and it is effective at removing air particulate. Building one requires an off the shelf HEPA filter, an off the shelf fan, and a couple of rubber bands. It isn't "sexy" or technically sophisticated, but it works. Want it improve effectiveness? Increase the surface area/make it bigger/increase the airflow. Let's also consider what both devices (when working correctly) do. An Ioniser gives particulate a charge causing it to be attracted to and stick on surfaces. A HEPA traps particulate within a filter membrane. Or to phase that differently an Ioniser causes the particulate to dust onto every surface within range, causing dirt buildup/stains, dust blooms when disturbs, and people may still contact the air contaminants (since they still exist, now on surface rather than in the air). HEPA allows you to simply remove the particulate from the environment, Ionisers just move it from one location (air) to another (surface).

seltzered_ 7y ago
Veritasium had a good video showing the test of ozone being produced by air ionisers: https://youtu.be/ZQ--scjcAZ4?t=663 https://youtu.be/ZQ--scjcAZ4?t=663 (time-linking since the ioniser part was sortof hidden within a video debunking himalayan salt lamps)
- pergadad 7y ago
  Thank you, really enlightening video. I'm happy I bought a HEPA filter now, rather than an ioniser.
NickBusey 7y ago
This is especially ironic in this case, because the entire premise of the article was: "I have always had the issue of dust settling in every week on everything if I open the windows. Cleaning that up every week is a pain." They then proceed to build a device that will, if anything, exacerbate this exact issue.
- arghwhat 7y ago
  The issue was "I have always had the issue of dust settling in every week on everything if I open the windows." If the dust is airborne, it will naturally spread everywhere before it eventually settles. Making the dust settle early minimizes spread.
raverbashing 7y ago
Another way of improving the homemade air purifier is adding an activated carbon filter (read: kitchen extractor hood filter)
amelius 7y ago
Can't you collect the dust at a particular location by using an opposite charge?
AstralStorm 7y ago
Ozone is actually a useful disinfectant, just make sure to ventilate the room well after treatment. Obviously not the outcome anyone building an ioniser is after.

ncmncm 7y ago

He talks about carbon-fiber stuff to get lots of ionization points, but steel wool works great. You will be able to smell if you are producing ozone, which you don't want unless you like permanent lung damage. The smell is sharp. like around electric sparks. If you get that, the voltage is too high. Just leave off a few voltage stages.

pbhjpbhj 7y ago
I love the smell of ozone though (not kidding!). I think it's an association from dicking around with dodgy electric motors (that sparked in a cool way) when I was younger.
- ncmncm 7y ago
  It's the same reason people like Lisp: it smells of youth.

deleted 7y ago

[deleted]

amluto 7y ago

As the former owner of a biggish HVAC-integrated electrostatic precipitator, these things are not really worthwhile. An ESP needs frequent cleaning to work well, in comparison to a plain old MERV 13 or so filter, which will work for quite a while with no maintenance. An ionizer doesn’t need maintenance, but that’s because it deposits all the gunk nearby. Eww.

m0xte 7y ago

Please don’t build this. There are numerous ways to kill yourself with it. Especially the construction as described.

hydgu 7y ago
Could you elaborate a bit more? I am curious from the technical side.
- m0xte 7y ago
  Lap soldered mains connection (can break off easily). Not double insulated (think small children and fingers). Also the actual ioniser port is usually recessed to avoid accidental contact as it hurts if you touch it. Also lots of hand soldered MLCC caps are high potentials. They like to crack and explode if you do that. They need to be machine soldered really. Edit: also the design doesn’t use proper voltage rated resistors on the output. I haven’t checked the other parts but it’s probably marginal. You’ll get home one day and find your house burned down.
  - chadcmulligan 7y ago
    could do with a fuse to. Those needles connected to active make me uncomfortable, though there's a 10M resistor, I'd have an isolating transformer on the mains - not an engineer though.
    - m0xte 7y ago
      Fuse would be good. Here in UK there’s one in the plug. The 10M resistor will current limit. Or probably flash over here. Isolation transformer is not required if the enclosure is better. It also doesn’t help you if you stick yourself across it somewhere, only helping yourself with respect to ground. If you’re testing it or doing development with it I would use one. But I wouldn’t build it. I used to hang around inside old valve radios when I was a kid. You learn respect for high voltages very quickly.

willis936 7y ago

$10 really means ripping apart and wiring up cheap Chinese consumer electronics. A PCB project is at minimum $100.

jvanderbot 7y ago

All comments seem to recommend a good old filter over an ionizer. Would an ionizer in series with a filter (e.g. in air ducts ) be more effective than a filter itself?

h2odragon 7y ago
For some uses. I have to recommend the commercial Honeywell units highly: they're excellent at pulling tobacco smoke and smell out of the air; and yes the area around them will catch all the other dust around too.

fortran77 7y ago

It is not healthy to breathe in high concentrations of ozone. It's difficult to make an "ionizer" that doesn't generate ozone. Also, the health claims of ionizers are dubious. False claims about them (and ozone) bankrupted The Sharper Image https://www.nytimes.com/2008/02/21/business/21sharper.html https://www.nytimes.com/2008/02/21/business/21sharper.html

eeZah7Ux 7y ago

You can buy a ionizer for less than $10 on aliexpress and it might be less electrically dangerous. However - DON'T DO IT. Many ionizers generate ozone which is unhealthy. Also if the goal was merely to combat dust settling on the floor (rather that health), it will only make the problem worse.

Tempest1981 7y ago
During crop-burning season in India, when the air is hazardous, would an ionizer + ozone be a net positive? Crop burn pics: https://www.theguardian.com/world/2019/nov/08/indian-farmers-have-no-choice-but-to-burn-stubble-and-break-the-law https://www.theguardian.com/world/2019/nov/08/indian-farmers...
- pbhjpbhj 7y ago
  Interesting, we banned it in the early 90s in the UK (I used to love watching it). https://www.eurekalert.org/pub_releases/2019-08/imaw-atb080719.php https://www.eurekalert.org/pub_releases/2019-08/imaw-atb0807... suggests there are better alternatives that will yield better returns for the farmers; but I gather some UK farmers want to return to burning as it - in their eyes - reduces weeds and provides ash for tilling in to the soil. It's not a simply equation though, eg https://www.researchgate.net/publication/230319729_The_effects_of_stubble_burning_and_tillage_on_soil_carbon_sequestration_and_crop_productivity_in_Southeastern_Australia https://www.researchgate.net/publication/230319729_The_effec....
- eeZah7Ux 7y ago
  No: ozone only makes things worse. Plus, a lot of smoke from burning plants has large particles that can be filtered much better with hepa filters

amelius 7y ago

> I these days use LCSC.com to buy all my generic parts. Great selection at a great price. It’s way cheaper than Digikey or Mouser. That's a good one, thanks!

Tempest1981 7y ago

An estimated power use of 4 kWh per year -- only costs 4 Rupees in Mumbai? (around $0.05 USD) That's surprisingly cheap power. The US average is 10x higher. ($0.13/kWh) Still a small cost ($0.52/yr in the US)

tomaszs 7y ago

Epic