When the two supply vents in workout room were originally installed they were installed incorrectly. This allowed the air from the HVAC system to go into the wall versus into the workout room. I dismantled and rebuilt both supply vents. There was also a broken 90 hidden behind a wall that was not allowing air to flow correctly into the living room. I cut the drywall and fixed the 90, then attached cut drywall. Customer is going to repair drywall himself.