Abstract: A displacement ventilation system for a room includes a first duct located inside the room and extending between a floor and a ceiling of the room, an air inlet coupled with the first duct for drawing air into the system, and an elongated diffuser extending adjacent the floor for diffusing at least some of the outside air over the floor of the enclosed spaced. The system includes a return air duct extending adjacent the ceiling and being coupled with the first duct for removing return air from the room and advancing the return air toward the first duct, and a heat exchanger for transferring thermal energy between the return air and the outside air. The heat exchanger has one or more heat conductive air filtration substrates integrated therein for conducting heat. A heat pump changes a temperature level of the outside air or the return air passing through the heat pump.

Abstract: A displacement ventilation system for a room includes a first duct located inside the room and extending between a floor and a ceiling of the room, an air inlet coupled with the first duct for drawing air into the system, and an elongated diffuser extending adjacent the floor for diffusing at least some of the outside air over the floor of the enclosed spaced. The system includes a return air duct extending adjacent the ceiling and being coupled with the first duct for removing return air from the room and advancing the return air toward the first duct, a heat exchanger for transferring thermal energy between the return air and the outside air, and a heat pump for changing a temperature level of the outside air or the return air passing through the heat pump. The system includes sensors located inside the room, and a controller for controlling operation of the system. The controller is in communication with the sensors.

Abstract: A displacement ventilation system for a room includes a first duct located inside the room and extending between a floor and a ceiling of the room, an air inlet coupled with the first duct for drawing air into the system, and an elongated diffuser extending adjacent the floor for diffusing at least some of the outside air over the floor of the enclosed spaced. The system includes a return air duct extending adjacent the ceiling and being coupled with the first duct for removing return air from the room and advancing the return air toward the first duct, a heat exchanger for transferring thermal energy between the return air and the outside air, and a heat pump for changing a temperature level of the outside air or the return air passing through the heat pump. The system includes sensors located inside the room, and a controller for controlling operation of the system. The controller is in communication with the sensors.

Abstract: A displacement ventilation system includes a vertical duct located inside an enclosed space and extending between a floor and a ceiling of the enclosed space, an air inlet coupled with the vertical duct for drawing air into the displacement ventilation system, and an elongated diffuser extending adjacent the floor for diffusing at least some of the outside air over the floor of the enclosed spaced. The displacement ventilation system desirably includes a return air duct extending adjacent the ceiling and being coupled with the vertical duct for removing return air from the enclosed space and advancing the return air toward the vertical duct, a heat exchanger for transferring thermal energy between the return air and the outside air, and a heat pump for changing a temperature level of the outside air or the return air passing through the heat pump.

Abstract: A displacement ventilation system includes a vertical duct located inside an enclosed space and extending between a floor and a ceiling of the enclosed space, an air inlet coupled with the vertical duct for drawing air into the displacement ventilation system, and an elongated diffuser extending adjacent the floor for diffusing at least some of the outside air over the floor of the enclosed spaced. The displacement ventilation system desirably includes a return air duct extending adjacent the ceiling and being coupled with the vertical duct for removing return air from the enclosed space and advancing the return air toward the vertical duct, a heat exchanger for transferring thermal energy between the return air and the outside air, and a heat pump for changing a temperature level of the outside air or the return air passing through the heat pump.

Abstract: Methods for assisting a technician in tuning a musical instrument exhibiting inharmonicity, such as a piano. If one aspect, a plurality of target frequencies are calculated using a table of preferred stretch values. In another aspect, target frequencies are calculated from multiple inharmonicity measurements during the time a tone generator is sounding.

Abstract: Methods for assisting a technician in tuning a musical instrument exhibiting inharmonicity, such as a piano. If one aspect, a plurality of target frequencies are calculated using a table of preferred stretch values. In another aspect, target frequencies are calculated from multiple inharmonicity measurements during the time a tone generator is sounding.

Abstract: A system and methods for assisting a technician in tuning a musical instrument exhibiting inharmonicity, such as a piano. A display informs the technician of one or more beat rates associated with respective intervals of a note being tuned and other notes. A second display informs the technician of the phase difference between the note being adjusted and a reference signal. The note being tuned is detected automatically, thereby allowing the technician to work without constantly touching the system. The wavelengths emanating from the notes are determined accurately, and the corresponding frequencies are tested for their quality before being used in calculations used for providing the information for the displays. A tuning frequency is calculated for each note after measurement of a first note, and the calculation is updated as more measurements are taken. If desired, the technician may visit each note only once in the tuning of the musical instrument.

Abstract: A system and methods for assisting a technician in tuning a musical instrument exhibiting inharmonicity, such as a piano. A display informs the technician of one or more beat rates associated with respective intervals of a note being tuned and other notes. A second display informs the technician of the phase difference between the note being adjusted and a reference signal. The note being tuned is detected automatically, thereby allowing the technician to work without constantly touching the system. The wavelengths emanating from the notes are determined accurately, and the corresponding frequencies are tested for their quality before being used in calculations used for providing the information for the displays. A tuning frequency is calculated for each note after measurement of a first note, and the calculation is updated as more measurements are taken. If desired, the technician may visit each note only once in the tuning of the musical instrument.

Abstract: A system and methods for assisting a technician in tuning a musical instrument exhibiting inharmonicity, such as a piano. A display informs the technician of one or more beat rates associated with respective intervals of a note being tuned and other notes. A second display informs the technician of the phase difference between the note being adjusted and a reference signal. The note being tuned is detected automatically, thereby allowing the technician to work without constantly touching the system. The wavelengths emanating from the notes are determined accurately, and the corresponding frequencies are tested for their quality before being used in calculations used for providing the information for the displays. A tuning frequency is calculated for each note after measurement of a first note, and the calculation is updated as more measurements are taken. If desired, the technician may visit each note only once in the tuning of the musical instrument.

Abstract: An optical device including a fluid filled prism that has flexible side wall portions to provide a variable lens system in conjunction with the prism. The device has translucent side walls formed in a trough shape with an open top side for conveniently changing the fluid in the prism body and thoroughly cleaning the interior side walls of the prism. The side walls of the prism are flexible through a range of spacings to provide a lens effect variation from concave to convex.