The invention provides an air-conditioner and an outdoor unit accumulated
snow judgment method and
system. The outdoor unit accumulated
snow judgment method is used for the air-conditioner and includes the steps that when an accumulated
snow judgment instruction is received, a fan is controlled to operate at a judged rotating speed; the real-time rotating speed of the fan is detected after preset time passes; whether the real-time rotating speed is lower than first preset rotating speed or not is judged; and if the real-time rotating speed is smaller than the first preset rotating speed, a first snow removing
signal is sent. By means of the outdoor unit accumulated snow judgment method provided by the invention, the accumulated snow condition is judged through the influence of accumulated snow on the fan of an outdoor unit. When snow is accumulated on the outdoor unit, the operation resistance of the fan is increased, then the rotating speed of the fan is reduced due to
negative correlation between the load and the rotating speed, by means of the characteristic, whether snow is accumulated on the outdoor unit or not can be effectively judged, the first snow removing
signal is sent in time so as to remind a user to remove snow, the heat exchange efficiency of the outdoor unit is guaranteed, meanwhile, the damage of the accumulated snow to a
machine is reduced, the structure is simple, and judgment is effective.