Hacker News Reader

Comment by random3 | Hacker News Reader

Can someone explain what's the result of filter utilization / capacity. Is it efficiency? Does it start spilling out particles?

I feel like a 100% used filter will still do a pretty good job, so unclear how much of the utilization % has commercial reasoning?

View on HN

I live in an very polluted area (average PM2.5 level in winter around 300 µg/m³) and have been running the same filter non-stop in a cheapest Xiaomi purifier for 1.5 years. It's almost black, but works fine, as confirmed by DIY PM sensors. I think it puts more strain on the motor, but I don't see any difference in efficiency.

My intuition is that the more “full” it is, the less air will flow through it, meaning it just doesn’t do as much.

Not to suggest that what the manufacture decides “100%” is is actually that.

That's exactly right for HEPA filters, not sure about other types of filters though.

This applies for any media filter. VFD drive on the motor can keep airflow constant and increase energy usage instead, but for most fans the increase in static pressure means less air volume. Heavily loaded filters can also have more air bypassing the filter, which may or may not be significant depending on the application. For this kind of air filter bypass just subtracts from the airflow through the filter media.

Efficiency in terms of airflow goes down, and static pressure difference goes up - but the filters trap more of the particles going through them. Changing filters on furnaces and AC units is really important, since lack of airflow hurts efficiency.

Wirecutter (which is usually trash) confirmed this in testing; versions of units that had been running for months or longer (ie one they bought a year ago and used in someone's home, vs a new unit bought new with little run time) tended to perform better in terms of how many particles they completely removed.

The unit starts using more electricity to do the same work, has to run at higher fan speeds, etc. So it's a tradeoff between that and the cost and waste generated by buying more filters.

curious - why is Wirecutter trash? I’ve been sorta feeling iffy about them for no real reasons but they seem highly recommended

With air purifiers at least Wirecutter completely ignores known problems in order to collect sweet, sweet referral fees. Comments about the high levels of VOCs in some brands' filters, fans exploding, etc. all get/got ignored.

In my case I bought a couple Coway air purifiers only to find that Coway doesn't honor their warranty. I hit all the common complaints from the comments section – comments Wirecutter staff refuse to acknowledge.

I was reading their list of coffee grinder recommendations. Some they recommend I got rid of years ago as they aren’t very good. It may be the case that they had a price ceiling, as the article mentions how costly grinders are, but it’s certainly dropped my opinion of Wirecutter.

They almost always conveniently only recommend products that allow for referral fees.

so pretty much anything sold by a major retailer?

The product manufacturers don’t pay referral fees, it’s the retailer. So your entire argument against them is you’re mad they make money by linking to Amazon or target?

> So your entire argument against them is you’re mad they make money by linking to Amazon or target?

That's not my entire problem with them, but it's a problem. Because they're reliant on referral fees their motivation is purely to get you to buy random crap whether or not it's any good. So long as their reputation holds up that's good, but once they start promoting crap there's going to be a long tail of folks who think "oh it's on wirecutter, it must be good".

Take a look at their reviews. It's not that they promote stuff that they might get a kickback on, Wirecutter only promotes stuff they can generate a referral link to.

I’d definitely prefer something like Consumer Reports who has the budget to expose scams like Molekule who claim to invent some magical new type of air purification.

Years ago, they really drilled into the performance of the various products they compared and frequently the winner was a specialist product from a brand you had never heard of, but it really was the best on the market. Wirecutter articles did good testing with defined rationale that might not be up to laboratory standards, but it was enough to clearly identify which products were offering the best performance. When they labeled a product "The Best X", you could be fairly confident that it was going to outperform almost everything else on the market. They tested everything from the highest range products to the garbage chinesium specials and if you read the entire article, you could see where some products might outperform in certain areas, but under perform in others, letting you make an informed decision that wasn't simply picking the "Winner". Effort had clearly been put into discovering a full range of products instead of simply comparing the amazon options. Any product that was disqualified from comparison had a clear and reasonable rationale.

Starting around 2018 the quality of testing plummeted into clickbait territory. Many articles appeared to justify their choices entirely based on reading amazon reviews without actually putting hands on the product, a theory reinforced by waves of comments appearing that despite a wirecutter recommendation, the product was absolute junk. My personal "Wirecutter is a lost cause" moment was when I was looking for a new comforter and the writer had simply disqualified every single option that was polyester based because "I don't like how polyester feels." That's not good testing. That's opinion. If I wanted subjective opinions on products I wouldn't be at Wirecutter.

For an contemporary example, pull up their "The Best Drill" article. The reviews highlight things you could discover from holding the drill and looking at it. The testing is a single test performed by a single person with no edge cases or alternative uses considered. If ergonomics are such a critical consideration that it gets entries shot down, shouldn't you have multiple people testing to see how different models perform in different people's hands? Furthermore, the only products tested are mid-range household drills available from big box stores. Nothing from the professional brands like Festool or Hilti or some brand I've never heard of. No explanation why I shouldn't just buy a Harbor Freight special for half the price. No explanation why any other consumer-grade brands weren't included. The articles don't provide "The best drill", they're providing "The best consumer-grade drill for light duty work", and this attitude has spread to every corner of the site. You can't go to wirecutter and find a specialist tool that outperforms the commonly available options any more, because they're not even including it in testing.

The Best Drill article doesn't even mention impact drivers, which are going to be tremendously easier on the wrist/hand for screwing in screws. An explanation for the lay audience would help. Nor are questions such as: "How much torque is there? What is the torque curve? How much torque do you need? Do you need a hammer drill? What is the noise like?" addressed.

I do think more specialty gear is hard to cover, as for example the the impact driver here: https://www.youtube.com/watch?v=l_pCeGmQU8w or AvE's youtube coverage of tools goes beyond that. Project Farm tends to have better coverage of general equipment with pretty good objective tests: https://www.youtube.com/channel/UC2rzsm1Qi6N1X-wuOg_p0Ng but even he can't cover all the brands/models: He covered Festool but not Hilti's SF 2H-A Hammer, for example.

Techgearlab has pretty unbiased coverage, and they also have an small incentive to cover products that have affiliate programs -- however, for example their parent rock climbing site Crash Pad Coverage: https://www.outdoorgearlab.com/topics/climbing/best-boulderi... includes Organic pads which have no affiliate program.

I should probably start off with: yeah, I don't like the Wirecutter drill article or find it useful. They eventually call out their intended target audience:

  For most household tasks, a 12-volt drill is more than adequate. It’s the smallest
  class of drill, and due to advances in battery and motor technology, such models
  have become formidable with regards to power. … If you’re a rabid DIYer with plans
  to build a deck, a doghouse, and a tree house, we recommend a stronger, 18- or 20-
  volt drill.

They're not reviewing higher end pro tools because that's not their audience. Were pros ever looking at WC for reviews? I know that for tools I'd be looking at more specialized folks like Project Farm or Torque Test Channel.

WC did cover the popular "pro" brands available in America (Milwaukee, DeWalt, Ridgid). Potentially they should've included Makita but Festool and Hilti are way beyond the price point of the home gamer target audience. Hilti especially goes after the fleet market, so even if you're a pro they're not necessarily going to be your goto brand unless you're at a larger company. Anecdotally Milwaukee kit seems to be very popular amongst tradesmen out here. But like with circular saws there's probably some regional variation.

I think WC did miss some important stuff for home gamers and they definitely got it wrong with the Bosch drill. It's small. It's tiny. It's about as long as the DeWalt and about an inch and a half shorter in height. You don't buy it for the power you buy it for the size. If you need to stand it up on the battery, get a bigger one with a foot.

https://www.nytimes.com/wirecutter/reviews/the-best-drill-fo...

My assumption is that a "Full" filter has a reduced airflow which means the fan pulling air in has to work harder. If it is spected very tight then I could see it failing more quickly.

Reply on news.ycombinator.com