Getting rid of the VOC source, if possible, is much easier than trying to filter it.

> Those 2-in-1 filters do exist but cost more. And many are scams because they don't have enough volume of activated carbon.

Any filter with a little bit of carbon added is going to be useless after a few days, or maybe even hours.

The only VOC filters that work have multiple pounds of carbon, with the good filters having upwards of 10-20 pounds. It also has to be replaced regularly.

I was referring to the gases from the cars on the highway more than easily removed indoor sources.

The pollution from highways is primarily particulate matter: Rubber from tires wearing down, brake pad dust, particles disturbed by fast vehicles and kicked into the air.

My common winix air purifier has a replaceable carbon filter.

Unless it has multiple pounds of carbon, it’s not doing much. These are for show.

Why would they cut corners? Activated carbon isn’t expensive.

Because it’s not obvious to most customers that a corner’s been cut. Same reason most new construction in the US sucks.

You can safely put a washer and dryer on the upper floor of a house if you add a proper floor drain, but you’re unlikely to see anyone add a floor drain in new construction because buyers aren’t looking for it. Now multiply that by everything a buyer isn’t looking for and you’re talking real money.

> You can safely put a washer and dryer on the upper floor of a house if you add a proper floor drain

European here, we've always been placing washer/dryer stacks in our bathrooms without needing floor drains. We have machines with a system called Aquastop [1] that stop the water flow if the machine detects a leak inside the system.

[1] https://de.wikipedia.org/wiki/Aquastop

In Denmark and I think Sweden it's a requirement that a washing machine is in a room with a floor drain.

Therefore the washing machine is usually in the bathroom, and the shower drain serves both purposes.

There’s a wide range of such designs due to the various different failure modes from false positives to the kinds of leaks resulting in 10’s of thousands in damages they are supposed to prevent.

What brand of washer do you use so I can studiously avoid it?

If the seal between the washing machine and the water supply fails it doesn’t matter which brand you’re using.

They have improved over time, but you need to have a drain for the washing machine anyway so the cost is quite low vs the rather extreme damage a leak can cause.

You simply cannot put enough activated carbon in a little foam thing that goes in front of a filter to do anything useful.

The real activated carbon filters have 10s of pounds of carbon. The little black foam thing that comes with those 2-in-1 carbon filters is useless.

And manufacturers do a sneaky swap too, my Coway 150 which is a great air filter by the way, came with a nice thick grid of hexagonal cells each filled with carbon granules - that insert alone weighs like half a kg. I ordered official filter and carbon filter replacements off their website ....got a thin carbon "foam" that weighs maybe 50g instead.

If anyone wants to get serious about VOC filtering, these things have 7 pounds of carbon in them, they’re made for filtering the air of weed grow ops: https://terra-bloom.com/collections/carbon-filters

You have companies choosing the component that cost 10 cents instead of 15 cents even if the 10 cents component will break 10 times faster than the more expensive one.

But it does cost money and so… corners are cut

The clue is in your name