It's not designed to work in those houses. It's specifically designed for homes with ducts. "The most common heating system in the US is a natural gas furnace

It's not designed to work in those houses. It's specifically designed for homes with ducts. "The most common heating system in the US is a natural gas furnace connected to ductwork, with the hot air ultimately coming out of vents in each room. This heat pump is a great replacement for the furnace and air conditioner in these ducted systems."