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Ceiling Air Purifier

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Re: Ceiling Air Purifier

#141

Post by mathgladiator »

bredren wrote: post #119
alexpw wrote: post #71

Earlier quoted context omitted.

> An updated design, also known as a Comparetto Cube, [1] uses four filters and a cardboard base that can sit directly on the floor. I never understood the purpose of the bottom filter in the Corsi-Rosenthal Box, so it felt like a waste of a filter, but I'm a big fan of the Comparetto Cube (no put intended). And 4 packs of filters are readily available -- 20x20x2 is suggested for the Comparetto Cube. [edit] Also, tha…

I have been focused on HVAC / air purification recently. Its amazing to me that these designs are less than two years old when the tech has been available for decades. One of the biggest problems with the C-R and comparetto is that they are large and hideous to look at. I have been working on a design that makes the C-R or comparetto or a smaller version than the 20" something that can be attractive enough to hang in…

Something that I remind myself of, often, (assuming it is true) is that airplanes were invented prior to putting wheels on baggage.

Re: Ceiling Air Purifier

#142

Post by phabricator »

sandbx wrote: post #40
sudden_dystopia wrote: post #4

Very cool. Now what can we do about the eyesore factor? Does this affect the fans cooling performance? The air blows more straight down than diffuse I am assuming due to the shroud?

it could be pretty if you light it well

I'm not sure mood lighting is going to do much for the duct tape on the ceiling (or what your ceiling will look like when you take it off)

Re: Ceiling Air Purifier

#143

Post by mistrial9 »

jefftk wrote: post #125
KennyBlanken wrote: post #124

Earlier quoted context omitted.

It's easy to add "legs" to the C-R device - a few dollars at most in wood dowels and no tools, for example. Maximizing filter area is really important because flow vs static pressure for a fan like this is usually logarithmic...and static pressure rapidly rises as the filters get used (their efficiency goes up, but flow drops.) That's one reason you see a lot of squirrel fans used in air filtration units; they can ge…

> Folks should really just buy a regular air filtration unit that uses much less electricity and is quieter This post is about how one of these made with a ceiling fan can be much quieter than a regular air filtration unit: "Testing my prototype, it has a CADR of ~180 CFM and is only 33dB. By contrast, the Wirecutter's top-recommended air purifier has a CADR of 233 CFM at 54 dB or 110 CFM at 36 dB. With some tweaks i…

virus in the air is dependent on effective filtration, rather than bulky particulate matter by volume.. the virus is highly contagious (few particles matter a lot)

Re: Ceiling Air Purifier

#144

Post by jefftk »

rapunkill wrote: post #123
kolencherry wrote: post #55

Earlier quoted context omitted.

Yes! This is the basis for the Corsi-Rosenthal Box [1]. Five 20"x20"x1" filters and a box fan, with duct tape to seal the edges. Not the prettiest, but it's effective. [1] https://en.wikipedia.org/wiki/Corsi%E2%80%93Rosenthal_Box

Not a new idea[1] I'm surprised it even has a name [1] https://www.youtube.com/watch?v=Uzpn09OIyqw

That's not the same concept: that requires tools and woodworking skill. A CR filter cube requires only a box fan, duct tape, filters, and the box the filters came in.

Re: Ceiling Air Purifier

#145

Post by jefftk »

TurkishPoptart wrote: post #130
kolencherry wrote: post #55

Earlier quoted context omitted.

Yes! This is the basis for the Corsi-Rosenthal Box [1]. Five 20"x20"x1" filters and a box fan, with duct tape to seal the edges. Not the prettiest, but it's effective. [1] https://en.wikipedia.org/wiki/Corsi%E2%80%93Rosenthal_Box

How is this significantly better than the parent comment of attaching one filter to a box fan?

It filters much more air with a single box fan. Box fans are optimized for flow, not pressure, and reducing resistance with four or five parallel filters means the fan can move much more air through its filters.

Re: Ceiling Air Purifier

#146

Post by ChuckMcM »

Nice work! I built a "Corsi cube" using 4x 20" filters and a 20" box fan. Some simple extrusions for the filter corners would be a win (and probably a good basis for a DIY kit).

Since the Corsi cube can be hung from the ceiling (it looks weird being a cube hanging up there) but it is ungainly. This is a much more elegant solution.

Re: Ceiling Air Purifier

#147

Post by jefftk »

hinkley wrote: post #103
jefftk wrote: post #101

Earlier quoted context omitted.

> Two, availability - no way you were finding five filters during a wildfire. Three, etiquette - if you found five filters that meant two other people weren’t getting any at all. Filters last a long time unopened: buy them in advance and store them until you need them, rotating stock.

Sure, but that’s hard to do when reading a tutorial that was posted after the sky turned orange. Edit: To your point though, help out the distribution networks by buying yourself an extra filter or two now, and put it on the shopping list every time you use one.

> To your point though, help out the distribution networks by buying yourself an extra filter or two now, and put it on the shopping list every time you use one

Yes! Socially we need to make a distinction between buying extras of things after an emergency has started (harmful) and doing it in advance (helpful)

Re: Ceiling Air Purifier

#148

Post by jefftk »

mxfh wrote: post #112
jefftk wrote: post #64

Earlier quoted context omitted.

Unless your ceiling is very high you probably wouldn't need a ladder to change the filters on a productized version of this. Reach up, twist something to unlock, old filter slides out, slide in new filter, twist to lock. Repeat for each filter going around. Ten minutes every six months?

Not to forget, you'll have a looming black octagon after 6 weeks or so already depending on your environment. At least a reminder, that the filters are doing something useful.

I've been running a filter cube in my office 8hr/day since November. It's a bit grey, but far from black.

Re: Ceiling Air Purifier

#149

Post by sammalloy »

mathgladiator wrote: post #141
bredren wrote: post #119

Earlier quoted context omitted.

I have been focused on HVAC / air purification recently. Its amazing to me that these designs are less than two years old when the tech has been available for decades. One of the biggest problems with the C-R and comparetto is that they are large and hideous to look at. I have been working on a design that makes the C-R or comparetto or a smaller version than the 20" something that can be attractive enough to hang in…

Something that I remind myself of, often, (assuming it is true) is that airplanes were invented prior to putting wheels on baggage.

It’s true. I don’t think popular, consumer grade luggage for the middle class had wheels until the 1970s. And if you watch for these kind of details in popular culture, I don’t think you even see wheeled baggage in the movies until the early 1980s. I couldn’t tell you the reason, but I think this was one of those status, income and class things: "I can afford to have someone carry my bags around."

Re: Ceiling Air Purifier

#150

Post by ChoGGi »

Kind of ugly looking... And that paint is probably coming off when the tape comes down

I had a new furnace/AC installed last year with a 4" filter. $50 CAD for a carbon filter and leaving just the fan on made a vast reduction in smoke smell during a wildfire or two from BC.

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