Blue shield plan fall tune up in 2007 Lennox Air handler. Customer had an issue with recent snow storm of home struggling to warm up. Thermostat was set to 68 and home was 62. After opening vents and doors the home did catch up, though. Checked filter, ductwork, plenums, evaporator coil, blower and blower capacitor. Checked sequencers, heat strips and electrical draws. System is operating within manufacturer specifications, but the ductwork does have issues as outlined from previous summer tune up. The returns are undersized and the supply ductwork has been run poorly, especially to the further reaches of home, causing air balance issues. After going over previous tune up recommendations, including heat load in attic due to poor ventilation and insulation, and ductwork design, customer is interested in having a return duct cut in in dining room area. Would like to run 1 16†duct from a 14x30 angle box to increase return air and help far reaching supplies get more velocity. Customer w