Energy Recovery Ventilators or Heat Recovery Ventilators are absolutely essential (and, I think, part of code in many places!) in this era of tight and sometimes extraordinarily tight (e.g. Passivhaus) home building.
When we bought our home, the HRV wasn't working and once I replaced a bunch of parts in it, the difference in the quality of the air was noticeable just in the fact that it smelled fresh like the outdoors.
In your deep dive, you probably ran into the evergreen debate about running ERV/HRVs in the summer... I just gave up, turn it off when we run the A/C and open the windows occasionally... BUT I think you could probably run a humidistat/hygrostat hooked to the HRV (a common option in the new units, I believe).
I’m based in Tokyo and have spent the past few months going down the rabbit hole of indoor air quality. It started out of concern for the health of our four-year old - lots of time indoors on account of the pandemic, etc.
We have HEPA filters in every room now and portable CO2, PM2.5, VOC monitors, etc for keeping an eye on things. As others have stated, however, this does nothing to address the VOC issue and so I am very keen to take the additional step of installing an Energy Recovery Ventilator or Heat Recovery Ventilator, as you suggest.
If anyone here has Japan or Tokyo-specific information on manufacturers, suitable systems and/or contractors capable of doing the work, I for one would certainly be grateful to hear it!
I'm in SF. The tricky thing here is that outdoor humidity is often so high that a humidistat would only result in an 'always on' system. I think CO2 is an objectively better measure anyway. You can remove humidity and particulate with energy efficient machines. You can't (realistically) do that with CO2 / VOCs.
When we bought our home, the HRV wasn't working and once I replaced a bunch of parts in it, the difference in the quality of the air was noticeable just in the fact that it smelled fresh like the outdoors.
In your deep dive, you probably ran into the evergreen debate about running ERV/HRVs in the summer... I just gave up, turn it off when we run the A/C and open the windows occasionally... BUT I think you could probably run a humidistat/hygrostat hooked to the HRV (a common option in the new units, I believe).