Abstract: A water heater system includes a gas burner configured to selectively produce flue gases, and a heat exchanger for heating water in the water heater system. The water heater system is operable in a heating mode, and a standby mode. An exhaust assembly is in communication with the heat exchanger, and includes a condensate collector configured to receive the flue gases and condensate. A first temperature sensor is positioned to sense a temperature of the condensate within the condensate collector. The first temperature sensor is configured to detect a rate of temperature change of the condensate. A controller is configured to determine a leakage when the rate of temperature change adjusts from a first state to a second state when the water heater system is in the standby mode after the water heater system was in the heating mode.

Abstract: A water heater system includes a gas burner configured to selectively produce flue gases, and a heat exchanger for heating water in the water heater system. The water heater system is operable in a heating mode, and a standby mode. An exhaust assembly is in communication with the heat exchanger, and includes a condensate collector configured to receive the flue gases and condensate. A first temperature sensor is positioned to sense a temperature of the condensate within the condensate collector. The first temperature sensor is configured to detect a rate of temperature change of the condensate. A controller is configured to determine a leakage when the rate of temperature change adjusts from a first state to a second state when the water heater system is in the standby mode after the water heater system was in the heating mode.

Abstract: A method for determining flow velocity in a flow path, comprises defining a flow path for a fluid, the fluid flowing in a downstream direction that is opposite an upstream direction. A thermally-conductive element is exposed to the flow path. A known amount of heat is applied to a first portion of the thermally-conductive element and a sensed temperature is sensed at a second portion of the thermally-conductive element downstream of the first portion. The known amount of heat and the sensed temperature are used to determine a flow velocity of the fluid in the flow path.

Abstract: A method for determining flow velocity in a flow path, comprises defining a flow path for a fluid, the fluid flowing in a downstream direction that is opposite an upstream direction. A thermally-conductive element is exposed to the flow path. A known amount of heat is applied to a first portion of the thermally-conductive element and a sensed temperature is sensed at a second portion of the thermally-conductive element downstream of the first portion. The known amount of heat and the sensed temperature are used to determine a flow velocity of the fluid in the flow path.

Abstract: A flow sensor includes a tube having a tube wall with a window in it. A thermally-conductive base covers the window and has mounted to it a heater and a sensor of a hot film anemometer flow sensor. The base is sealed to the window to resist leakage of fluid from the flow path through the window under normal operating pressures. The hot film anemometer flow sensor is used to measure fluid flow through the tube.

Abstract: A flow sensor includes a tube having a tube wall with a window in it. A thermally-conductive base covers the window and has mounted to it a heater and a sensor of a hot film anemometer flow sensor. The base is sealed to the window to resist leakage of fluid from the flow path through the window under normal operating pressures. The hot film anemometer flow sensor is used to measure fluid flow through the tube.

Abstract: A motor includes a shaft that extends along a rotational axis and an end frame that includes a first surface that is substantially normal to the axis. A first plurality of annular features are arranged concentrically about the rotational axis and coupled to the first surface. A fan is mounted to the rotating shaft and including a slinger portion and a second surface. A second plurality of annular features are arranged concentrically about the rotational axis and coupled to the second surface. The first plurality of annular features cooperate with the second plurality of annular features to form a non-contact seal between the fan and the end frame.

Abstract: A motor includes a shaft that extends along a rotational axis and an end frame that includes a first surface that is substantially normal to the axis. A first plurality of annular features are arranged concentrically about the rotational axis and coupled to the first surface. A fan is mounted to the rotating shaft and including a slinger portion and a second surface. A second plurality of annular features are arranged concentrically about the rotational axis and coupled to the second surface. The first plurality of annular features cooperate with the second plurality of annular features to form a non-contact seal between the fan and the end frame.