Gary Turner

Solid state physicist (retired). Born at 309 ppm CO2. Same handle on the 🦋, where I plan to post in future as well as here. Follow ≠ approval.

[Gary Turner @DtaGuy]

Finally! I built & tested an open-source concept model air purifier that should be good for schools. Lots of air (CADR > 420 CFM), quiet (<45 dBA), uses <9 W, and ‘cause it’s wall-mounted & down-blowing, it moves air in the right direction & takes up no floor space.👀my ALTs🧵⬇️

[Gary Turner @DtaGuy]

@ghhughes I'm puzzled by the chart. Assuming log scale label 0 is really 0.1 um, why don't efficiencies go up at 0.2 um & why so low. 3M MERV 11 HVACs at 2.5 m/s = 492 FPS are 77% 1-3 um. Maybe low fiber density to make 'em breathable at all for small area? Dunno what gsm 3M uses.

[Gary Turner @DtaGuy]

@Engineer_Wong @ghhughes In that case I would need to set a weekly alarm to take it outside for a bitof fresh air.

[Gary Turner @DtaGuy]

@Engineer_Wong Looks great! It's will all depend on the specs. It does look like it might rattle around in the cup holder, maybe fixed with a detachable ring of wings. Or a gooseneck mount with it's base in the cupholder, so you could point out at your face.

[Gary Turner @DtaGuy]

@RikLesel @viksterluv1 @OC_Scanner Outstanding simulation. Thanks.

[Gary Turner @DtaGuy]

@allanxchen @OCFireAuthority I understand side reactions and thermal degradation generate acrylic acid, methacrolein, methanol, and CO₂, but I imagine all of these except CO₂ would have been detected by whatever VOC monitors they have. If total vapor pressure was low, why the crack?

[Gary Turner @DtaGuy]

@ArnoldLabour @open_erv If you can find the time, it would be interesting to autopsy the cable, looking at the wire below the melted cover. Won"t change anything, but it's a puzzle.

[Gary Turner @DtaGuy]

@JN1171 @Liesl4CleanAir @Engineer_Wong I didn't know about cross-flow fans. I wonder what their flow-pressure-noise characteristics are!

[Gary Turner @DtaGuy]

@Liesl4CleanAir @Engineer_Wong https://t.co/QUUgRjoD58 I hear you, Liesl, on the 2 installations and 2 plugs. But for a large room, one unit means higher airflow and higher noise on one side, much less of both on the other. Total filter area is the same, and roughly same number of fans.

[Gary Turner @DtaGuy]

Configuration is important. Warm human aerosol rises toward the ceiling. The idea is to scavenge warm, dirty air from the ceiling, filter it, & blast it down along the wall, where it can spread out over the floor & convect back up past the occupants’ faces. See ALT for more.

[Gary Turner @DtaGuy]

@Liesl4CleanAir @Engineer_Wong My guess is that 2 or more purifiers totalling that CFM would be more efficient. But whatever works.

[Gary Turner @DtaGuy]

@BarryHunt008 Plus, you can get snot on both your shirt and your chest in one go!

[Gary Turner @DtaGuy]

The biggest downside is cost if you don’t have a CPAP. But if you do, it’s as close to bullet-proof as you’re gonna get at the dentist. And leave the filter on for home use, unless you need to get to the memory card. It’s like sleeping with a mask. 4/4

[Gary Turner @DtaGuy]

For the dentist, I’ve stolen @BarryHunt008’s idea https://t.co/B42e6YzlxR. I taped an Aura N95 over the inlet of my ResMed 10 CPAP, removing the itty-bitty internal filter. I use a ResMed P30i cannula with over-the-head inlet.@LazarusLong13 🧵⬇️1/4

[Dr. Sean Mullen @drseanmullen]

Made 🦷 appt for May 20th. It’s not perfectly aligned w/ the virus lull (seeing lots of people sick locally), but there is never a perfect time. Hygienist will wear N95 & I’m bringing my AirFanta Wear instead of my Respiray. Can’t help but think it’d be more effective for the hygienist to use (in reverse) against their mask (replacing face shield). Thoughts @Engineer_Wong?

[Gary Turner @DtaGuy]

Barry used a big Canadian mask, but an AURA is smaller and a little trickier. Click ALT text for more details.⬇️3/4

[Gary Turner @DtaGuy]

@open_erv @Engineer_Wong @ghhughes I'm an old coot with a hobby, not a gifted entrepreneur like @Engineer_Wong or @open_erv. Schools and businesses won't buy it until it's commercially available, and they don't have really good options yet. Home sales might get a wall-mounted unit there.

[Gary Turner @DtaGuy]

@Engineer_Wong @ghhughes I'd love it if you'd make a wall-mountable unit like Nukit's Tempest Pro, but with downward outflow. If quiet and attractive I'd buy it for home use, and with an optional room occupancy sensor, maybe schools would buy them too.

[Gary Turner @DtaGuy]

@Engineer_Wong I agree with @ghhughes , make what sells, stay in business and keep innovating. I tell everybody I know about my 3Pro. I have 2 Wears, but don't really use them. They're a great design, but the problem of personal wear purifier is really hard .

[Gary Turner @DtaGuy]

@open_erv Or even an axial baton to discourage yaw/pitch relative to the axis of rotation. A weight on a rigid stick is often used on tripods for that purpose.

[Gary Turner @DtaGuy]

@open_erv I wonder if a heavy metal plate on the back of the motor would help.