Patent ID: 8679261

Claim:
A box-type warewasher for washing wares, the warewasher comprising: a housing defining an internal treatment space for receiving wares to be washed and a liquid sump below the treatment space; a wash liquid delivery system that provides a spray of liquid within the treatment space, including a wash pump having an input connected to the liquid sump and an output connected to deliver liquid to one or more spray nozzles of the treatment space; a rinse liquid delivery system including a rinse pump for delivering rinse water to one or more spray nozzles of the treatment space; a closed loop heat recovery system for recovering heat from hot moist air present in the treatment space, the heat recovery system including a heat exchanger external of the treatment space, a blower for moving hot moist air from the treatment space across the heat exchanger and back to the treatment space: wherein the heat exchanger is located in a heat exchange compartment that is adjacent the treatment space, the heat exchange compartment having an inlet opening from the treatment space to the heat exchange compartment and an outlet opening from the heat exchange compartment to the treatment space, the blower located between the inlet opening and the outlet opening to circulate hot moist air from the treatment space into the heat exchange compartment, across the heat exchanger and back into the treatment space, and the heat exchanger is a heat exchange coil through which cold water flows so as to pick up heat from the hot moist air flowing past the heat exchanger; a programmed controller is associated with the wash liquid delivery system, rinse liquid delivery system and heat recovery system, the programmed controller configured for carrying out at least one ware treatment program sequence in which: (i) the wash liquid delivery system is operated for spraying hot wash liquid onto wares in the treatment space; (ii) subsequent to spraying of wash liquid, the rinse liquid delivery system is operated for spraying hot rinse liquid onto wares in the treatment space; and (iii) subsequent to spraying of rinse liquid, the heat recovery system is operated to move hot moist air from the treatment space, into the heat exchange compartment and back to the treatment space to reduce moisture level of air in the treatment space prior to completion of the ware treatment program sequence; wherein the programmed controller is configured such that the heat recovery system is operated as a final step of the ware treatment program sequence, upon completion of the heat recovery step a cycle complete indicator at an external surface of the warewasher is triggered to identify cycle completion for an operator; wherein a duration of the heat recovery step is between about 10 seconds and about 60 seconds.