Human detection devices 8 that detect the number of people in conditioned spaces supplied with conditioned air from the use side heat exchangers 12 and control means 9 and 50 that controls an amount of refrigerant supplied to the use side heat exchangers 12 by controlling opening degrees of the expansion devices 5 on the basis of detection results of the human detection devices 8.

An occupancy sensing electronic thermostat is described that includes a thermostat body, an electronic display that is viewable by a user in front of the thermostat, a passive infrared sensor for measuring infrared energy and an infrared energy directing element formed integrally with a front surface of the thermostat body. The passive infrared sensor may be positioned behind the infrared energy directing element such that infrared energy is directed thereonto by the infrared energy directing element. The thermostat may also include a temperature sensor and a microprocessor programmed to detect occupancy based on measurements from the passive infrared sensor.

An occupancy sensing electronic thermostat is described that includes a thermostat body, an electronic display that is viewable by a user in front of the thermostat, a passive infrared sensor for measuring infrared energy and an infrared energy directing element formed integrally with a front surface of the thermostat body. The passive infrared sensor may be positioned behind the infrared energy directing element such that infrared energy is directed thereonto by the infrared energy directing element. The thermostat may also include a temperature sensor and a microprocessor programmed to detect occupancy based on measurements from the passive infrared sensor.

A system and method of minimizing the time between opening a hot water valve and hot water reaching a point of use by temporarily diverting the water to another point of use. The system and method embody a thermally sensitive valve arranged so as to permit the flow of cool water from a hot water supply line to be diverted to a point of use that is insensitive to the temperature of the water provided. Embodiments of the invention may also comprise timers that function to limit the amount of time that water may flow to a point of use that is insensitive to the temperature of the water provided. Such embodiments may operate without user intervention or may require that a user or other device provide a signal that causes the invention to divert water to a point of use that is insensitive to the temperature of water provided.

To provide a motor control device capable of properly compensating the fluctuation in inverter output voltage during a dead time. The motor control device is for an inverter including switching elements composing upper and lower arms to convert a direct-current voltage to an alternating-current voltage and apply the alternating-current voltage to a motor thereby controlling a current of the motor to be a current target value, the motor control device including a dead time compensation unit that compensates fluctuation in inverter output voltage during a dead time with each switching between the upper and lower arms by a dead time compensation voltage, wherein the dead time compensation unit acquires an input parameter that determines a polarity of motor current during the dead time in a half-cycle of a fundamental wave of the motor current, and varies the dead time compensation voltage according to magnitude of the input parameter.

A wall-mountable programmable electronic thermostat for controlling an HVAC system is described. The thermostat includes a circular wall-mountable backplate with a central opening to allow for the passage of HVAC wires for electrical connection to the thermostat. The head unit body is also circular and is removeably mountable to the back plate. A plurality of wedge-shaped wiring terminals are mounted on the backplate for making a tool-free connection to HVAC wires. Each wiring terminal has button that a user can depress while a wire is inserted in a wire hole. The terminals are arranged along one or more circular arcs about the central opening of the backplate such that the wire holes face the central opening and the buttons are located close to the outer periphery of the backplate.

Described herein is a motor comprising a first rotatable member and an anchor, spaced apart from the first rotatable member. The motor also comprises a belt, in tension about the first rotatable member and the anchor. The belt is co-rotatably engaged with the first rotatable member. Further, the belt is made from a shape-memory alloy. Additionally, the motor comprises a thermal regulation device, positioned between spaced-apart first and second portions of the belt. The thermal regulation device is also configured to concurrently cool the first portion of the belt to contract the first portion of the belt and heat the second portion of the belt to expand the second portion of the belt. Concurrent contraction and expansion of the first and second portions of the belt cause rotation of the belt.

An occupancy sensing electronic thermostat is described that includes a thermostat body, an electronic display that is viewable by a user in front of the thermostat, a passive infrared sensor for measuring infrared energy and an infrared energy directing element formed integrally with a front surface of the thermostat body. The passive infrared sensor may be positioned behind the infrared energy directing element such that infrared energy is directed thereonto by the infrared energy directing element. The thermostat may also include a temperature sensor and a microprocessor programmed to detect occupancy based on measurements from the passive infrared sensor.

An occupancy sensing electronic thermostat is described that includes a thermostat body, an electronic display that is viewable by a user in front of the thermostat, a passive infrared sensor for measuring infrared energy and an infrared energy directing element formed integrally with a front surface of the thermostat body. The passive infrared sensor may be positioned behind the infrared energy directing element such that infrared energy is directed thereonto by the infrared energy directing element. The thermostat may also include a temperature sensor and a microprocessor programmed to detect occupancy based on measurements from the passive infrared sensor.