Our L-shaped ranch home is on a cement slab and our current forced-air oil-furnace vents are in the ceiling. We are going to be renovating and are considering 1) converting to propane and 2) placing the new unit centrally on a loft in the attic. We've heard that with the newer units, the air temperature coming from ceiling vents could feel cool instead of warm. Is this true with all units? Is there a better solution?

Placing heating systems in an attic space is very common and if insulated ducts are installed along with the new unit, there will be no loss of heat by this configuration.

Only side note, however, is that propane will end up costing you more to heat with than oil in most locations.

My suggestion is to consider electric baseboard heat instead.

It has gotten to be cheaper than any other form of heat in many US loactions, and actually has been the cheapest form of heat for at least 5 years in my part of the northeast.

Electric is the cheapest to install, the easiest to maintain, the most efficient to regulate, and more often, the cheapest to use.

Interesting. We are with Niagara Mohawk and none of the builders have suggested electric--they've all recommended propane as being less expensive and more efficient than oil. I will look into this further. Thanks.