Separate Airhandler or Add Coil to Furnace
I have begun to extensively remodel my home. Right now, the project does not include replacing or modifying the existing furnace and supply ducts, which are all connected to floor registers. The system works pretty well as is. Someday though, it would be nice to have some central AC, which I will use only occasionally (i.e., I am in an area where the performance of the heating system is more important than the performance of the AC system).
Because all of the furnace supply ducts terminate at floor registers, is it infeasible to simply add a coil and condenser to the existing furnance sometime after the remodeling is finished? Assume that the furnance is a relatively late model unit with different blower speeds for heating and cooling.
If floor registers just won't cut it for AC, while the remodeling is going on, I can install some ceiling registers and ducting in the attic, and plan to eventually have a separate AC airhandler installed there. If that is the way to go, I have two additional questions:
Is it o.k. if the nearest location for the outside condenser is almost 50' feet from where the separate AC airhandler will be installed (i.e., 25' horizontal and 25' vertical)?
If the AC airhandler is located near the return duct for the furnace, can the return duct be used for the airhandler as well as the furnace ? Assume that the AC airhandler is going to generate less CFM than the furnance (i.e., I am not looking for nearly as much AC as heat in the house)?
I may never pull the trigger on the central AC, but while all the remodeling is going on, it would be helpful to know what the approach will likely be if I do.