My house is old & air conditioner upgrade never seemed possible because of this.
I did not have the wall space to get a ductless mini split device.
I also had a heating plan & I only need cooling. Ductwork upgrade with central air conditioner would have ruined our house. In order to get air ducts the Heating & A/C company needs to rip the walls & ceiling down to the bare bones. My house is not structurally sound enough to handle this, but so for a long time I was making due with window a/cs in the summer. It was extravagant to run all those little cooling devices & they were hideous. Dust was also an issue since the window A/C units sat stationary for a long time. After doing some research I found that I can get high velocity AC. This plan does use HVAC duct to create whole house cooling, however the air ducts are better. The HVAC duct is half the size & stretchy. The Heating & A/C company did not have to take down our walls; He could truly fit the tiny Heating & A/C ducts in the walls with very little disfigure. The air ducts bend truly to accommodate the structure of the house. The cooling plan works great with the little ducts too. The air suddenly whips through the smaller ducts & our house is icy cold, however no more energy wasting window A/C units & being still too hot. I have the benefits of central air conditioner without the work involved. I also think our high velocity plan is better than central AC.