Most French homes use radiators or under-floor heating to distribute heat to each room. The UK is a little different. While offices may use ducted heating, most homes use boilers to heat the water. Then they move the hot water around the house to heat the radiators. One of the advantages of air-to-air heat pumps is that they do not require a boiler to heat the house.
Air-to-air heat pumps use fan coils/blowers to heat. Blowers are usually installed high in the wall and are suitable for homes with limited wall space. Ducts are commonly used in newer homes because they are often installed in ceiling voids to avoid damage.
Air-to-air heat pumps can have one indoor fan or multiple fans. A heat pump with only one indoor fan is called a single-seal heat pump. A multi-seal heat pump has an outdoor unit and multiple interior fans. In general, single-seal air-to-air heat pumps only heat small homes or rooms. You may need a multi-seal air-to-air heat pump or a ducted system if you have more than two rooms.
You can install an air-to-air single fan system quickly and cheaply. A multi-seal unit requires a pipe from an external heat capture device to each fan. Typically, these pipes run in long plastic tubes at the edges above the room to make them as invisible as possible.
