Apparatus for cooling or freezing products that can be operated in the IQF and non-IQF modes, comprising: a conveyor for transporting products through a cooling medium in the IQF and non-IQF modes, said conveyor having an upper surface and a lower surface； a conveyor motor to move said conveyor； at least one stirring assembly comprising at least one cam fixed to at least one camshaft, said at least one camshaft being mounted with the allowed rotation below said lower surface of said conveyor, such that the cam makes initial contact with the conveyor when the vertical component of the cam speed is at its maximum or near its maximum during each 360º rotation of the camshaft； and an independently controlled stirring motor functionally associated with at least one stirring assembly to drive the stirring assembly to cause agitation of the conveyor and the products located thereon when said apparatus is operated in the IQF mode, in which said at least one cam is located in such a way that the linear vertical speed is maximized just before said at least one cam hits said conveyor.Aparato para refrigerar o congelar productos que se puede hacer funcionar en los modos IQF y no-IQF, que comprende: un transportador para transportar productos a través de un medio de refrigeración en los modos IQF y no-IQF, teniendo dicho transportador una superficie superior y una superficie inferior； un motor del transportador para mover dicho transportador； al menos un conjunto de agitación que comprende al menos una leva fijada a al menos un árbol de levas, estando dicho al menos un árbol de levas montado con el giro permitido por debajo de la citada superficie inferior del citado transportador, de tal manera que la leva hace un contacto inicial con el transportador cuando la componente vertical de velocidad de la leva está en su máximo o cerca de su máximo durante cada giro de 360º del árbol de levas； y un motor de agitación controlado de forma independiente asociado funcionalmente al al men
