I recently bought my first home in upstate NY and would like to replace my old gas down draft furnace. It may be original, 1950s or so... not really sure. The new combo units that provide whole house heat and on demand water are intriguing. But I don't know if these are right for my situation. My house is small, around 1000 sq. ft., one level, no basement, ranch style with an attic/crawl space. There is no existing duct work, instead the furnace and hot water tank are located in the middle of the house. I would like to add the duct work and move the furnace / tank to the attached garage. But I'm also not sure if that is possible or cost effective. Please help in pointing me in the right direction. Thank you.