yeah well i already told you about heat exchangers that can intake fresh air while recovering the heat from exhausted air ...

they could theoretically recover as much energy as you want depending on design - both heat and cold - that way you could breathe 100% fresh air while barely using any energy for HVAC ...

unfortunately due to low IQs something like that will never be used until Klaus Schwab and WEF make it mandatory ...

because nobody buying a home bothers to test air quality of energy efficiency - all people look at is price and location ...