Came out today for a air flow issue. Upon arrival the homeowner stated that the whole hose heats except her daughters room located on the first floor. This is a air temp furnace model #Kg7sk072c-24b1, serial # Kgg161200098. Upon inspection I found that there was a duct added to the system located right off of the supply. This duct is for the second floor. The first floor is cold while the second floor is hot. I closed two of the vents on the 2nd floor the third vent you are not able to close. But still there is very little air flow going to the downstairs. I explained to the homeowner that once you add ductwork to an existing system especially right off the supply you will loose air flow in other areas.