An apparatus for cooling or freezing items or products comprising: - a housing comprising a ceiling , a floor and side walls defining a chamber within the housing ; - at least one conveyor extending into the chamber between the ceiling and the floor ; and - at least one impingement apparatus disposed in the chamber and above the conveyor , said impingement apparatus associated with the conveyor and comprising: (a) a shell supporting an impinger wherein the impinger is supported by the shell on lower edges or lips of the shell ; and (b) a coolant delivery apparatus enclosed within the shell , the coolant delivery apparatus comprising a gas circulation device for directing a coolant to the impinger ; the impinger comprising: (i) an impingement plate comprising openings for directing impingement jets toward the conveyor ; (ii) at least one non-circular cam ; and (iii) at least one connector in mechanical communication with the at least one cam and the impingement plate , the connector displaceable during rotation of the at least one cam to elevate and lower the impingement plate , wherein the at least one non-circular cam is in mechanical communication with the at least one conveyor and rotatable when the conveyor is in motion. - a housing comprising a ceiling , a floor and side walls defining a chamber within the housing ; - at least one conveyor extending into the chamber between the ceiling and the floor ; and - at least one impingement apparatus disposed in the chamber and above the conveyor , said impingement apparatus associated with the conveyor and comprising: (a) a shell supporting an impinger wherein the impinger is supported by the shell on lower edges or lips of the shell ; and (b) a coolant delivery apparatus enclosed within the shell , the coolant delivery apparatus comprising a gas circulation device for directing a coolant to the impinger ; the impinger comprising: (i) an impingement plate comprising openings for directing impingement jets toward the conveyor ; (ii) at least one non-circular cam ; and (iii) at least one connector in mechanical communication with the at least one cam and the impingement plate , the connector displaceable during rotation of the at least one cam to elevate and lower the impingement plate , wherein the at least one non-circular cam is in mechanical communication with the at least one conveyor and rotatable when the conveyor is in motion. (a) a shell supporting an impinger wherein the impinger is supported by the shell on lower edges or lips of the shell ; and (b) a coolant delivery apparatus enclosed within the shell , the coolant delivery apparatus comprising a gas circulation device for directing a coolant to the impinger ; the impinger comprising: (i) an impingement plate comprising openings for directing impingement jets toward the conveyor ; (ii) at least one non-circular cam ; and (iii) at least one connector in mechanical communication with the at least one cam and the impingement plate , the connector displaceable during rotation of the at least one cam to elevate and lower the impingement plate , wherein the at least one non-circular cam is in mechanical communication with the at least one conveyor and rotatable when the conveyor is in motion. (i) an impingement plate comprising openings for directing impingement jets toward the conveyor ; (ii) at least one non-circular cam ; and (iii) at least one connector in mechanical communication with the at least one cam and the impingement plate , the connector displaceable during rotation of the at least one cam to elevate and lower the impingement plate , wherein the at least one non-circular cam is in mechanical communication with the at least one conveyor and rotatable when the conveyor is in motion. <EOS>