Just curious if I should do anything or just leave the system alone.
I have a 3-ton Carrier 13 SEER AC unit installed about 5 years ago. The house is 1,100 square foot ranch home (small). I have re-insulated the attic since installing the AC. The AC is combined with my Oil-fired Carrier 84K BTU furnace. The house is in New York State. Lower end of the state.
I haven't done any load calculations, but I have to imagine that 3 tons is way too much for the home and I am paying much more electric costs than I need.
Is it economical to switch the AC to a smaller size? Are there more things involved than simply switching the outside unit?
The furnace is fine, i only use about 350 gallons of fuel oil in a typical winter and the house is comfortable at 67 degrees, so I wouldn't want to replace it.
The AC is comfortable, but it doesn't remove humdidity as well as it should and I always feel like I am paying for this huge AC unit to run when I may just need a tiny one. But I don't want to switch it out if it will take 10 years to recover the cost or something like that. I only want to switch it out if it is a "no-brainer".
Duct work in the house consists of one major rectangular duct and then individual 5-inch metal ducts feeding the individual registers. The air for both the heat and ac comes out of the ducts very rapidly. I have one return vent located in a back hallway about 1.25 ft by 2.25 ft (haven't measured it).
The fan is noisy and also the sound of the air going through the vent is pretty noisy. I have learned to live with the noise however. It is really the energy usage that I am concerned I am using way more electricity than I need to be.