Picture a typical one-level, three bedroom ranch sitting on a full basement and heated with forced hot air gas heat. Now, turn the attached one car garage into a family room, 21' x 15', (minor sub-floor underneath). Next, knock down the back wall of the garage and put an additition on, 14' x 15' (sitting on a crawl space.
How do you heat it?
This was done before I bought the house and a supplemental gas fired furnance was installed. It's called a gravity furnance, and emits heat from both sides, installed on a wall shared by both new rooms. Heat seeps out, mostly from the middle and upper portions of the unit, and heats the ceiling nicely. The problem is your toes are cold and by the time the thermostats register the change in temp, it's way too hot. Also, it's used way too much gas. Near to impossible to find a blower unit for the heater.
Any suggestions? I've thought about extending duct work through a closet and the attic for ceiling vents in the other room, although I'm not sure the main furnance can meet the demand. We live in Rhode Island, with the heat running from late Sept. through April or May. Coldest temps outside are 5-15 F, occasionally dropping below zero.