installing duct system for diesel heater and air conditioner

[levenezia]

On the boat I just ordered, the factory, (Tartan) offers air conditioning but not a diesel heater. So the diesel heater is aftermarket. My question is, since I can''t see having two duct systems, will the duct system for the factory installed air conditioner be adequate for the diesel heater? It makes sense to install the duct system during the building process so I''m hoping it will be adequate for the heater as well. Do the two systems have to have separate duct systems? Larry

[GordMay]

YES - A combined (single) Heating & Air Conditioning Duct system is perfectly acceptable.
Many duct systems, as installed on boats, are improperly sized (too small).
You want to ensure that the manufacturer has properly sized the ductwork (bigger is better) to accommodate the highest anticipated air volume (either A/C or Heating), at a reasonably low air velocity, with respect to the installed static pressure (drop). The outlets (registers) must also have adequate free area.
Gord