Looking for some direction, we've had several different HVAC suggestions from different contractors.

Adding a second story to a 1955 walk up attic cape in CT. Heating is hot water radiators w/oil boiler (old), indirect water heater (15 yr old amtrol). Want to add ac and new boiler/furnace. At first we thought easy - go with hydro on second, stay radiators first floor, add loop of registers to basement. BUT, the HVAC contractors we've spoken with recommend taking the radiators on the first floor, particularly because we're adding ductwork anyway and it gets rid of low hanging heating system pipes in the basement.

OK, we like radiator heat, but seems to make sense from a cost perspective to switch.

Forced air for whole house at that point or hydro? Seems like forced air is the best option - some say hydro extra cost, also why heat water to heat house.

OK, but what about hot water if we go to forced air? We love indirect hw concept because never run out. Have heard either hw tank or some say tankless. I'm afraid of tankless after all I've read (will have 3 full bathrooms).

Convert to gas or keep oil? Surprised to hear all say yes to gas, gas line already in house for heat and dryer - no brainer.

I think we're at the point where we're converting to gas furnace, all forced air, but what are my hw options? It's a priority for us to never have hw be an issue.

I've even had a heat pump solution offered.

Thoughts? Many thanks in advance for your opinions!

Convert to gas.
Have your contractor install a condensing gas boiler. They are about 95% efficient when run with a 140 degree water temperature.
Forced air heat will never be as good as radiator/baseboard heat.

Agreed - we very much like the radiators, but they're recessed in the wall and have 2 coats of paint on them. Would need to try to refinish them (big job?) and if we keep them on 1st floor, we have to relocate all heating piping in basement for ceiling pipe and ac ductwork. If we remove, we can tear out the piping.

This may be a dumb question, but if we remove them, does it make any sense to go with hydro at that point or just go for a furnace with humidifier system?

Thanks

That is a personal decission for you to make.