It’s designed for use with low temperature distribution systems such as radiant floors, and can be ordered with or without a cooling mode. It includes a 3kw backup electric heater. The system can not only heat the house, but also cool it. The heat pump is then equipped with a reversible four-way valve, whereby the refrigeration cycle is reversed and heat is removed from the rooms. The indoor unit can cool rooms via under floor cooling or fan coil units.