Heating tune up Buford. Completed tune up on 2 2 year old furnaces. Downstairs furnace running good. With good air flow clean blower and evap coil. Changed filter. Safety switches working. Electrical components working properly. Upstairs system is all the same except air flow is very restricted. Not enough return air for the upstairs. Recommend adding return to computer room. Customer wants to do it. Will call to schedule.