Abstract: A laundry dryer includes a rotatable drum and an air delivery system. The air delivery system can include a reversible blower that provides air at a first flow rate when operated in a first direction and provides air at a second lower flow rate when operated in an opposite second direction. The drum can be a reversibly rotatable drum that is rotatable in a first and an opposite second direction, and the dryer can include a drive motor that both rotates the drum and operates the blower. Drum and blower reversal may be controlled to optimize drying efficiency and also reduce stress on the drive system. A moisture delivery system can provide moisture (e.g., water mist or steam) into the drum while air is being provided at the lower second flow rate, and during drum rotation (tumbling).

Abstract: A laundry dryer includes a rotatable drum and an air delivery system. The air delivery system can include a reversible blower that provides air at a first flow rate when operated in a first direction and provides air at a second lower flow rate when operated in an opposite second direction. The drum can be a reversibly rotatable drum that is rotatable in a first and an opposite second direction, and the dryer can include a drive motor that both rotates the drum and operates the blower. Drum and blower reversal may be controlled to optimize drying efficiency and also reduce stress on the drive system. A moisture delivery system can provide moisture (e.g., water mist or steam) into the drum while air is being provided at the lower second flow rate, and during drum rotation (tumbling).

Abstract: To control a temperature of a dryer system, particularly a laundry dryer, an ON/OFF relay control is employed to switch heater loads. A plurality of heating elements is used in order to more precisely regulate the temperature inside the dryer system. Further, a heating control system that includes a plurality of symmetric heating elements and a control circuit is used to maintain equal distribution of relay switching loads, resulting in an extended lifetime of each individual relay. Asymmetric heating elements may also be used.