Hacker News Reader

Comment by fellowniusmonk | Hacker News Reader

What sensors do you use? I have a bunch of air filters but just leave them running all the time.

I use airgradient sensors.

On the other hand, instead of DIY you could just buy air purifier units with integrated air quality sensors. A friend of mine uses these, they appear to work very well https://www.philips.co.uk/c-p/AC2936_33/2000i-series-air-pur...

I got a Philips air purifier with such a sensor, it's a different one though (it's oval and just white at the sides).

I would not recommend it purely because they decided to use an extremely poor touch interface for control which quiet often doesn't register when I try to manually adjust something like shutting the unit down temporarily or resetting an error code

Honestly, that still sounds like a minor inconvenience compared to DIY. Those things seem pretty set-and-forget beyond filter replacements.

Also don’t stress yourself out about air purifier quality. The only thing that matters is the disposable filter and the difference between cheap and expensive is how fast they can move air through it. They all reach the same destination.

Buying a purifier that can fit standard sized “box” filters will save you $$ in the long run.

There are aesthetic concerns, it’s harder to have a bunch of air purifiers spread around your home if they’re ugly as sin.

Having one very powerful air purifier hidden away in another room is not as good as having a bunch of smaller ones spread around.

Not exactly, price increases with some certifications and branding. In the high end of purifiers, they can handle much smaller particulates and gasses (e.g. carbon matter measured by dozens of lbs with replacement filters costing hundreds). The most effective filters for general use will have higher CFM. CFM also decreases with smaller particulate filtering. Unless you're spending ~$1k+, most activated be carbon seems to wear out faster than it's worth considering.

Overall, yes, a cheap box filter (placed specifically in the bedroom, if limited to one room) is often the most effective.

> Unless you're spending ~$1k+

Speaking of expensive air purifiers, you can often find excellent deals on used IQair units. I got 4 GC Multigas units from a local museum for 100 euros each.

I have an alert set up on the local craigslist equivalent and constantly get emails.

Aren’t the filters super expensive though? I see the ones for the health pro listed at 115.- each.

They do last much longer than the cheaper filters.

How often do they require charging?

I’ve changed mine once after 4 years of moderate use in a quite well insulated 1700 sqft apartment with wood floors, no carpets but a decent amount of visitors and occasional tiny dog.

Those filters were used though, no idea for how long (they only had like 70 hours on them according to the onboard tracking, but that would be easy to manipulate even by accident)

This essentially tracks with the numbers presented here https://www.iqair.com/newsroom/why-you-need-to-replace-your-...

IQair recommends a yearly replacement for my HEPA filter, but my environment had a fairly low amount of particulates to begin with (new building with filtered air intakes) and workload split between multiple units.

Reply on news.ycombinator.com