Am I correct in saying that the furnace isnt allowed to have return openings to the garage. Also doesnt the open vents break the fire wall?
The furnace didnt work & it is older. I Recommended a HVAC specialist. Wouldnt it be better if they selaed the outside at the garage and used the returns at the interior rooms? The closet had a opening into the interior but the access was sealed & blocked.
I did note the condensate needing to be discharged properly. Nice trench!!