> How much does implementing all that cost? What degree of benefit does it offer over simple window in situations where those concerns are negligible? What other benefits to human life could be procured with that money?
Everywhere not being LA is actually an argument for ERVs/HRVs. The weather in LA (AIUI) is fairly even and consistent and it is probably fairly easy to just open a window.
But if you're in Texas with high humidity, or Arizona with high heat, or north of the Mason-Dixon line where people get winter, it's kind of hard to open a window when it's 0 or -10 outside. If you have stale air (perhaps as measured by high CO2) what are you supposed to do?
Over the July 4, 2026, weekend it's supposed to get >90F/>32C on the east coast of the US: do you want to open your windows and let all of that heat in? Especially if you already have an AC unit so paid to run it get your home's inside temperature down?
If you have a place with ducts, you can purchase an ERV and tap into that for US$ 1000:
* https://www.hvacquick.com/products/residential/HRVs-and-ERVs...
or even less:
* https://hvacdirect.com/air-cleaning/erv-air-exchangers.html
And even in milder climates (like LA), have the ERV suck in air from the outside through an MERV 13(+) carbon filter, and not only do you deal with things like wild fire smoke, but wild fire smell:
* https://www.greenbuildermedia.com/blog/wildfires-make-indoor...
* https://shop.aprilaire.com/products/aprilaire-513cbn-odor-re...
It is possible to make your indoor air cleaner than the air outside.