When You want to heat and cool a room efficiently this unit is the right one for you. With 12000 BTU Cooling and 10800 Heating BTU this unit is capable of cooling and heating rooms up to 450 SF. This unit comes with Heat pump heating which is the most energy efficient way to heat a room. When the temperature outside falls below 25 degrees the electric heat will kick in automatically and will efficiently heat the room. The EER (Energy Efficiency Rating) of this unit is the highest in its class with 9.4 EER which will run at low cost on energy.