From the specs it looks like they are probably closer to higher-static-pressure server fans, the CADR is a few hundred CFM and it pulls 30+ watts. And as with many of these designs, you can compensate for low pressure performance by increasing filter surface area... the greater the surface area the lower the pressure drop. Of course, the problem with this is you are just spending more money on filters, which is the expensive part.

▲ jerlam 8 hours ago | parent | next [-]

The filter cost for the AirFanta 3 doesn't seem particularly high? In fact it seems cheaper than competitors.

All the purifier companies realized they make more money selling overpriced filters, so $60+ for the OEM filters is common nowadays. Despite it just being a standard HEPA filter cut to a specific size.

Airfanta 3 Pro filters (four) - $57

Coway Mighty Filter - $60

Coway Mighty2 Filter - $70-$80

I'd be concerned about the availability of filters after a few years. Some of these companies have been changing their models and filter type every year to add some nebulous feature. Others just go out of business.

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kube-system 7 hours ago | parent [-]

Yeah, the retail prices of filters is all over the place because of the popularity of razor/blade model of pricing. I'm not talking about that, I'm talking about the BOM itself -- this device is using 4x the filter media of comparable filters, which would typically have one filter that size.

HEPA media itself is a commodity and aftermarket filters (and the BOM cost to the OEM) tend to level out at whatever rate is minimally profitable per area of filter media.

The upfront cost of this device is high for what you get, because you're mostly buying filter media. The device itself is not much of a polished product. I'm sure it works fine but I wouldn't want one in my living room.

	▲	jefftk 5 hours ago \| parent [-]
		I have three in my living room, and while they're not fashion they blend in fine: https://photos.app.goo.gl/wvRc4hEYqQep4zgd9 I leave them on setting 2 (unless someone is sick or we're having a lot of people over), and we get ~425 CFM for about $40/y in power (~5W each).

▲ schiffern 10 hours ago | parent | prev [-]

  >Of course, the problem with this is you are just spending more money on filters, which is the expensive part.

For up-front cost, this is true.

For cost over time, twice the filters means twice the replacement interval, so the additional filter cost cancels out.

▲ kube-system 7 hours ago | parent [-]

But since you bought mostly media, you didn't get a housing that hides the media, and you get to look at any collected dirt for that longer interval as well...

I'm sure it works but like any engineering decision it has pros and cons.

▲ schiffern 7 hours ago | parent | next [-]

  >you get to look at any collected dirt

If that's your biggest worry in life, seems like a high-class problem! Many people are satisfied 'just' protecting their heart and lung health.

However, if you really don't want to look at it, you can always flip most DIY designs inside-out so the fans blow in and dust collects on the inside instead of the outside! This doesn't clean the room quite as efficiently, but if the appearance of dust is a major concern that should be a fix.

	▲	kube-system 6 hours ago \| parent [-]
		Yeah it’s functionally fine but I would opt to buy a more polished product for the above reasons. Probably would be great for a shop or similar, which is where I’ve done DIY purifiers myself. My personal favorite for cutting down on dust during home projects is a 20x20 furnace filter slapped on the intake side of a box fan. It requires zero extra parts or assembly. Flipping the fans isn’t great because then you have to clean the fans, this is why draw-through is the standard configuration. Also many designs like this rely on negative pressure to seal properly or even stay together. You might just have the lid take off like a helicopter.

▲ jefftk 5 hours ago | parent | prev [-]

It just looks grey, but the housing is also grey, so I don't think it generally reads to people as dirty.