New System Help Please

[Scarlet]

Hello-
QUSTIONS:
What are the pro and cons of a boiler versus a furnace? (I am installing ducts to the home)
What impact does choosing one of the other have on central AC?
What impact does it have on my ability to add a 2nd zone?
Should the vents, off the ducts, be located in the floor or in the ceiling?

FACTS:
Small cape style home in MA (less than 800 square feet on the 1st floor).
The walk up attic is used mainly for storage, but does have radiators (although I never turned them on).
I would like heat to go upstairs but have it zoned separately since I do not use the space today. Perhaps in the future I would expand the size of the house.
Several contracts have said zoning is difficult, but I have many friends with zoned heating systems so I am not clear why this is an issue. They contracts suggest I purchase two units, which seem extreme to me given the size of the home (even if I did expand it someday it would never be larger than 1,600 square feet).
Thank you for any insight you can provide.
PS, the heating system today is a boiler is from the 1940s with forced hot water radiators. I am removing the boiler, radiators, oil tank and hot water heater getting a new gas energy efficient system and adding ducts to the home.

[beenthere]

Moved to residential forum.

[heaterman]

Since you are planning on removing all traces of a hot water heating system, why would you then reinstall a boiler from scratch as well as a ducted AC system. Better to go with a zoned forced air system using a high efficiency gas furnace and AC system. Without running all new hot water heating radiators and piping you would need a wet coil installed in an air handler to use a boiler in conjuction with a forced air duct system just adds cost and lowers efficiency. Depending on local utility costs you may want to consider an add on heat pump as an upgrade over a regular cold AC only system. Forced air zoning is not all that difficult but can be expensive and you need to use a contractor that is comfortable with that type of system. Since your home is on the small side, it should not be difficult to achieve a balanced temperature through out. Floor supply registers will work fine in conjunction with high / low returns.

[crmont]

Since you are planning on removing all traces of a hot water heating system, why would you then reinstall a boiler from scratch as well as a ducted AC system. Better to go with a zoned forced air system using a high efficiency gas furnace and AC system. Without running all new hot water heating radiators and piping you would need a wet coil installed in an air handler to use a boiler in conjuction with a forced air duct system just adds cost and lowers efficiency. Depending on local utility costs you may want to consider an add on heat pump as an upgrade over a regular cold AC only system. Forced air zoning is not all that difficult but can be expensive and you need to use a contractor that is comfortable with that type of system. Since your home is on the small side, it should not be difficult to achieve a balanced temperature through out. Floor supply registers will work fine in conjunction with high / low returns.

Ditto:D

[DGIO-Not]

"Capes" by design are difficult which is why forced air zoning is not being discussed. We usually cannot get a return up high upstairs (they usually put supplies in the knee wall.) Your biggest problem with designing your system is finding someone to actually do the Manual J and Manual D.

I love Boiler heat and we do have ways of converting systems and a little more leeway for "zoning" to a Cape style home. This will not get you cooling or dehumidification, so now you are talking a very expensive retrofit if insisting on heat or heat/cool.

My suggestion, go ahead and abandon the use of the boiler, but do not remove the hydronic system. You may just wish to convert in the future. There is a real "warm & fuzzy" with these systems that cannot be compared to conventional Forced Air Systems.