Silver club, returned to check air flow and temperatures for dampened project on 7/24/2020. Took before readings, velocity coming from vent is 431 fpm, temp leaving vent is 64 degrees. Ambient temp in room is 75 degrees. Went in attic and adjusted damper, which is top eighth as you face the furnace in the back side, leading to the adjoining sub room to master suite. Damper was set to be 30% closed when installed. Adjusted it to be completely opened. Also felt for any more sources of air leaks on plenum and found 3 deteriorated spots. Sealed those spots properly. Took new measurements. Velocity leaving vent was 630 fpm, temp leaving vent was 53 degrees. Room temperature from my gauge after 20 minutes of run time dropped to 69 degrees and was reading 73 degrees on customer wall thermostats. ***Because this add on room has no to minimal ceiling insulation, the damper will likely need to be readjusted to be closed during cooler weather when the furnace is used.*** the damper is the top