A warewash machine comprising: a housing that at least in part defines a chamber with a wash zone, the chamber having front, left and right access openings; at least one spray arm disposed above or below the wash zone, the spray arm configured to spray liquid toward the wash zone; and a multi-sided hood assembly including movable front, rear, left, right and top wall sections, the multi-sided hood assembly movable between a lowered and closed position for washing and a raised and open position for inlet and outlet of wares, wherein in the raised and open position each of the front, rear, left, right and top wall sections is raised to form a space to retain hot water vapor inside the multi-sided hood assembly; a stationary chamber rear wall, the stationary chamber rear wall including at least one air exchange opening; an air exchange system located rearwardly of the stationary chamber rear wall, the at least one air exchange opening fluidly connected with the air exchange system, the air exchange system including at least one secondary housing defining, at least in part, a first compartment and a second compartment; wherein the first compartment includes a condenser therein, wherein incoming water to the machine from a cold water input passes through the condenser, wherein the first compartment includes an air outlet to a surrounding ambient environment, a first air mover associated with the first compartment and selectively controllable for moving hot water vapor from the chamber, into the first compartment, over the condenser and out of the air outlet; wherein the second compartment includes at a least one heater therein and an air inlet from the surrounding ambient environment, a second air mover associated with the second compartment and selectively controllable for moving ambient air into the air inlet, past the heater to be heated and into the chamber. a housing that at least in part defines a chamber with a wash zone, the chamber having front, left and right access openings; at least one spray arm disposed above or below the wash zone, the spray arm configured to spray liquid toward the wash zone; and a multi-sided hood assembly including movable front, rear, left, right and top wall sections, the multi-sided hood assembly movable between a lowered and closed position for washing and a raised and open position for inlet and outlet of wares, wherein in the raised and open position each of the front, rear, left, right and top wall sections is raised to form a space to retain hot water vapor inside the multi-sided hood assembly; a stationary chamber rear wall, the stationary chamber rear wall including at least one air exchange opening; an air exchange system located rearwardly of the stationary chamber rear wall, the at least one air exchange opening fluidly connected with the air exchange system, the air exchange system including at least one secondary housing defining, at least in part, a first compartment and a second compartment; wherein the first compartment includes a condenser therein, wherein incoming water to the machine from a cold water input passes through the condenser, wherein the first compartment includes an air outlet to a surrounding ambient environment, a first air mover associated with the first compartment and selectively controllable for moving hot water vapor from the chamber, into the first compartment, over the condenser and out of the air outlet; wherein the second compartment includes at a least one heater therein and an air inlet from the surrounding ambient environment, a second air mover associated with the second compartment and selectively controllable for moving ambient air into the air inlet, past the heater to be heated and into the chamber.