In an aspect, an HVAC system includes an inducer motor to provide combustion airflow, and a pressure sensor to measure an output airflow pressure of the inducer motor. The HVAC system may initiate the inducer motor, and receive a pulse width modulation (PWM) signal from the inducer motor, wherein the PWM signal indicates a PWM signal of the inducer motor corresponding to a predetermined airflow pressure of the inducer motor and measured by the pressure sensor. The HVAC system may compare the PWM signal to a baseline value, and control the inducer motor based on the comparing of the PWM signal to the baseline value. The HVAC system may also generate a status notification of the combustion airflow of the HVAC system in response to the comparing the PWM signal to the baseline value.

A method of controlling an RPM of a blower for a gas furnace that passes air to be supplied to a room around a heat exchanger of a gas furnace, the method including starting operation of the gas furnace; measuring an air temperature in an outlet side of the gas furnace; measuring the RPM of the blower; determining whether the air temperature falls within a reference temperature range; and adjusting the RPM of the blower such that the air temperature falls within the reference temperature range.

Disclosed are systems and methods for automated furnace inducer sensor output verification. A furnace may include a sensor, such as a transducer, that may be used to measure pressure within the furnace (for example, pressure resulting from the operation of a draft inducer blower and/or any other component of the furnace). It is possible that the data produced by the sensor may remain relatively fixed for a given period of time. However, this makes it difficult to determine if the data is valid or if the sensor is malfunctioning. Given this, an algorithm is used to change a motor speed of the inducer blower. The subsequent data that is produced by the sensor is then monitored to determine if an expected change in the data occurs. If the change does not occur, then it may be determined that the sensor is malfunctioning.

In a control method of a washing machine, a primary nephelometric turbidity unit (NTU) of washing water is sensed before a washing course is started in a washing cycle, a second NTU is sensed based on the primary NTU, and a washing time, an amount of washing agent, and/or a number of times of rinsing are varied based on a difference value between the primary NTU and the secondary NTU, thereby improving washing performance and washing efficiency.

A gas supply system for a flame module of a spectrometer and a method of controlling a flame module. The gas supply system comprises an oxidant gas supply line for providing a supply of oxidant gas, an oxidant gas flow valve for varying a gas flow rate of an oxidant gas in the oxidant gas supply line, an oxidant gas safety controller configured to control the oxidant gas flow valve, a fuel gas supply line for providing a supply of fuel gas, a fuel gas flow valve configured to control a gas flow rate of a fuel gas on the fuel gas supply line, and a fuel gas safety controller configured to control the fuel gas flow valve. During normal operation, the oxidant gas safety controller is configured to charge an energy storage circuit of the oxidant gas safety controller. In the event of a power failure, a first switch of the oxidant gas safety controller is configured to connect the energy storage circuit to the oxidant gas flow valve, wherein the energy storage circuit is configured to discharge energy to the oxidant gas flow valve to increase the oxidant gas flow rate in order to extinguish a flame of the flame module, and the fuel gas safety controller is configured to close the fuel gas flow valve.

A temperature control system includes a blower impeller assembly that has a blower impeller, a motor coupled to and configured to drive the blower impeller, and a sensor that is coupled to the motor and configured to measure current drawn by the motor to maintain the blower impeller at a set angular speed. Further, the temperature control system includes a controller that is communicatively coupled to the sensor. The controller electronically detects at least one of a blockage in a vent coupled to the temperature control system and a malfunction of the blower impeller based on an amount of the current drawn by the motor to maintain the blower impeller at the set angular speed.

A control module for preventing acoustic resonance noise generation from a heat exchanger of a heating furnace, comprising a control signal generated by the control module. The control signal is configured to operate an induction fan of the heating furnace at more than one speed for a given heat demand mode of the heating furnace.

A furnace controller for a modulating furnace that helps provide a balance between energy efficiency and occupant comfort across various burner firing rates and/or across various circulating blower speeds. In some cases, the furnace controller can be configured to permit a user to customize operation of the furnace in accordance with their particular needs and/or desires with respect to efficiency and comfort. A selection may be made between an energy efficiency setting and a user comfort setting. Then, a plenum parameter such as a discharge air temperature (DAT) or discharge air flow (DAF) may be regulated in accordance with the selected setting.

The present invention provides a gas water heater, and a safety control method and system therefor. The system includes: an exhaust fan; a rotational speed detecting unit, configured to detect a rotational speed of the exhaust fan; a power obtaining unit, configured to obtain a set value for output power of the exhaust fan; a rotational speed difference obtaining unit, configured to obtain an actual value of the rotational speed and a reference value of the rotational speed according to the set value for the output power, and to calculate a difference between them; and an exhaust control unit, connected to the exhaust fan, the rotational speed detecting unit, the rotational speed difference obtaining unit and the power obtaining unit respectively, configured to correct a predetermined wind pressure curve graph at an air outlet of the exhaust fan according to the difference.

A high-efficiency modulating gas furnace (herein gas furnace) includes a furnace controller. The gas furnace further includes a gas valve and at least one pressure switch that is coupled to the furnace controller. The electrical contacts of the at least one pressure switch are removed from a series electrical circuit with the gas valve such that the gas furnace operates without de-energizing the gas valve as soon as the electrical contacts of the at least one pressure switch are opened. Further, the furnace controller operates the induced draft blower at or close to a lowest RPM at which the electrical contacts of the at least one pressure switch can be kept closed, which is between a make point RPM at which the electrical contacts of the at least one pressure switch close and a break point RPM at which the electrical contacts of the at least one pressure switch open.