What type of hrv system should I put in a 4 year old home?
...remove moisture and provide fresh air.
I would say you are best to start by familiarizing yourself with the idea of mechanical ventilation, you can do that starting here on this page –
Does a house need an HRV / ERV air exchanger?
It is true that houses are being build more airtight in this day and age than in the past...
Posted by Ellen Murray Zappone
Sept. 1, 2021
HRV and ERV