We just closed today on an old farmhouse that has hot water baseboard heat and no A/C. DH and I are discussing the pros & cons of various options.

I like radiant heat (have lived with radiators before), but dislike that all outside walls have ugly baseboards and interfere with furniture placement.

DH suggested that since we need to duct the house for central A/C, we just add a furnace.

However, I have a lot of allergies, and found that living with radiant heat was very preferable to having so much dust being blown about (we have 2 dogs, too). When DH offered that an air cleaner can be put on the A/C air handler, I stated that I thought it could be run during heating season for an hour or so a week to help clean the air without having the A/C on.

We live in an area that has LOTS of old houses and can find radiators frequently on Craig's List. In fact, we have 6 that we bought with the intention of using them as a heat sink for a greenhouse. But now I want to use them in our new home, along with however many more we need to have sufficient heat.

So.... my questions are: How hard is it to convert from HW baseboard to radiators? How do you calculate how many you need/size of room? Should the upstairs be plumbed separately from the down? Or should each radiator be plumbed back to the HWH? Any advice on putting back into service radiators that may have been sitting for a while?

We both agree that we like the redundancy of having multiple heat sources (oil heat, wood stove, and one room with a small gas soapstone stove). Also 2 rooms that were added on later are on a slab, and we're planning on radiant floor heat for them.

All advice would be most welcome!