Our house is two years shy of it 100th birthday. It has beautiful, albeit painted radiators that function really well. We figured we would keep the radiators, since they provide a dryer, more comfortable heat, and we would add individual thermostatic radiator valves to each of them to control the heat. However, the house did not have any air conditioning. There was one window unit installed in one room upstairs, and two dead window units in the basement. We decided we would install a dual-system AC unit in the property.
1. We have four floors, it would be more efficient
2. Basement and first floor would get Standard Central AC since we would be able to build bulkheads without looking to intrusive.
3. Third and fourth floor would get a small duct high velocity system.