US Patent 8434317 Anti-sweat heater demand supply module using temperature and humidity control

A refrigerated appliance such as a refrigerator receives a demand response signal indicating a peak demand period and operates the refrigerator in an energy savings mode by disabling an anti-sweat heater. Sensors monitor ambient temperature and humidity, and the dry bulb temperature of a preselected region where incipient moisture would likely form. Data from the sensors is sent to a controller which calculates ambient dew point and compares the dry bulb temperature of the preselected region with the calculated dew point to enable the anti-sweat heater during the peak demand period and prevent incipient formation of moisture.