Dedicated return line

[gelert]

Hi all, I am trying to estimate what % of detached homes in the US have a dedicated hot water return line currently? Any ballpark guesses based on your experience? Thank you!

 

[Breplum]

Required on new home construction in CA. Affluent communities with larger homes have much higher percentage that small homes. Junk science guess: 1.2%. Homes we work on: 40%