Hello, I have two split Comforter brand heating and A/C units. They are fourteen years old. I have done the maintenance on them myself yearly cleaning coils, units in attic and compressor units outside and inspecting the ductwork. I have always taken good care of them and change my filters regularly and oiling motors as outlined in maint. Manual. I noticed that the upstairs unit has not been very cool the last couple of years. I have blown approx. 4 to 6 inches of new insulation in the attic covering almost all of ductwork and installed a ventilation fan set to come on at 90 degrees. I also have a friend that is a plumber and has a license to buy freon. He took a look at my units and put gauges on the high and low side of the compressor. He also compared the downstairs unit and said that everything looked OK. I took temp readings yesterday on the air blowing out of the registers upstairs and measured 68 to 70 degrees in the morning with the temp. outside of 76 degrees. The temperature slowly creeps up all day and max out at 80 degrees with the temperature coming out of the register at 75 degrees outside temp. at 92 degrees. I checked the downstairs and it was blowing a consistent 63 degrees out of register and I can see a change in temperature in a very short period. I also checked the large copper hoses coming off the compressors and the downstairs is much cooler than the upstairs. They are not sweating. I would like to know what may be the problem? I have max out upstairs today at 80 degrees and it is now coming down at 79 degrees at 8pm. I have invested approx. 15k into house to put on market and sell. I have a really tight budget. Thanks for any help that you can give!

Call a true professional and have the systems inspected and corrections made. That is the best advice anyone can give you. There are many aspects to proper cooling and that needs to be addressed by a ON SITE inspection. All else is guess work and no wants to guess with your money.