I just moved into a big old foreclosed rowhome in Baltimore. I've had guys working in there to straighten it out for month now - it's an old beast that ate the previous owner's shirt, and I am a first-time homeowner myself. ~3500 sqft on 3 finished floors, over an unfinished basement. Dual-zone AC system installed. Heating system is old natural gas boiler + radiators.
The house will be empty almost all day M-F, so I've been investigating how I can supplement the heating system so we can keep the boiler temp low but be able to quickly bump the heat up when we get home. I suggested branching a new pipe from the supply side of my boiler and running it to the basement air handler located 15' away on the same wall, and installing a hot water coil inside the air handler. I figure my idea was a cheap and simple way to force hot air to the main floor when we get home, but both my contractor and his HVAC subs thought it was a strange/difficult solution. Is the problem that I need an air handler specially designed for hot water heating, or that I'd have to have a cutom water coil sized? Or are these guys incorrect? My contractor is suggesting gas fireplace installations, and his HVAC guys said to install an electric heater in the air handler.