Disclosed are a method and a device for controlling refrigerant in an air conditioning system. The method includes: S1: comparing a superheat degree of each outdoor unit with an average superheat degree; S2: if the superheat degree of a present outdoor unit is higher than the average superheat degree, and a first different between the superheat degree of the present outdoor unit and the average superheat degree is greater than a present value, increasing a refrigerant amount entered into the present outdoor unit; and S3: if the superheat degree of the present outdoor unit is lower than the average superheat degree, and a second different between the average superheat degree and the superheat degree of the present outdoor unit is greater than the present value, decreasing the refrigerant amount entered into the present outdoor unit. Therefore, the refrigerant amount entered into each outdoor unit is adjusted from systemic overall perspective.

A system and method for advanced digital economization for an HVAC system having an economizer. A digital processing unit is configured to open a damper of an economizer within a dead-band range that allows for preemptive cooling prior to a call for cooling. This economization strategy allows for free cooling (outside air) without having to pay energy costs for cooled (air-conditioned) air. The system and method can be used with or without demand control ventilation (DCV). The method also includes a “self-learning” strategy with outside air and return air sensor to regularly sense past economizer damper modifications and average out recent readings to help set the dead-band range. The method can include the ability to work in conjunction with a variable supply fan speed control, provide fault detection, self-correct, auto-configure, and report system status.

An air conditioner includes an outdoor unit and a plurality of indoor units connected to the outdoor unit. The outdoor unit sometimes sets an evaporation temperature or a condensation temperature that is different from a value that any of the indoor units has requested from the outdoor unit. The indoor units have indoor-side controllers that perform capacity control that adjusts capacity based on a degree of superheating or a degree of supercooling, an air volume, or an evaporation temperature or a condensation temperature while calculating a requested capacity that is determined from a current room temperature and a set room temperature. The indoor-side controllers, when performing the capacity control, determine at least one of the air volume and a target value of the degree of superheating or the degree of supercooling based on the evaporation temperature or the condensation temperature that is set by the outdoor unit.

Climate control devices and methods are disclosed. A climate control device includes a housing, an ultrasonic emitter, an ultrasonic receiver, and a controller. The housing defines a receptacle for receiving liquid. The ultrasonic emitter is positioned to emit an ultrasonic wave toward a surface of the liquid received in the receptacle. The ultrasonic receiver is positioned to receive the ultrasonic wave after the ultrasonic wave reflects off of the surface of the liquid. The controller is configured to provide a liquid level indication based on the ultrasonic wave received by the ultrasonic receiver. A climate control method includes receiving liquid in the receptacle, emitting an ultrasonic wave toward a surface of the liquid in the receptacle, receiving at least a portion of the ultrasonic wave after the ultrasonic wave reflects off of the surface of the liquid, and providing a liquid level indication based on the received ultrasonic wave.

An integrated ventilation unit configured to provide ventilation and conditioned air to an indoor space may include a heat pump system, an energy recovery device and a control unit. The heat pump system may include a first coil located at a supply air side of the ventilation unit, a second coil located at an exhaust air side of the ventilation unit, and a compressor. The energy recovery device may be configured to transfer heat between a return air stream and a supply air stream and the control unit may be configured to control operation of the heat pump system and the energy recovery device.

The present disclosure provides a method and a device for adaptively regulating a static pressure of a ducted air conditioner, and a ducted air conditioner. The method includes: dividing the static pressure in an air duct into a preset number of sections; selecting the sections i and i+1, and detecting respectively the gears corresponding to the sections i and i+1, the rotating speeds R.sub.i and R.sub.i+1, and an actual working currents I.sub.i and I.sub.i+1; and judging whether I.sub.i and I.sub.i+1 are within the normal current ranges respectively; and selecting the final section according to the judging result. With the method, the air duct conditioner may automatically select and determine a section according to actual installation environments, and may automatically determine an optimum section in which the ducted air conditioner works.

One aspect presents a controller that comprises a control board, a microprocessor located on and electrically coupled to the control board, and a memory coupled to the microprocessor and located on and electrically coupled to the control board. The controller is configured to receive an operating parameter signal and recalculate a first maximum heating % demand to a second maximum heating % demand that is greater than the first maximum heating % demand, when a value of the operating parameter signal exceeds a predetermined value, and operate the HP system based on the second maximum heating % demand.

A humidifying device includes an air inlet, an internal air passage through which air taken in from the air inlet passes, a first thermometer that measures a temperature of the air taken in from the air inlet, a first hygrometer that measures a humidity of the air taken in from the air inlet, a cooler installed in a path of the internal air passage, and a cooling control unit that controls the cooler. The cooling control unit changes a cooling intensity of the cooler in a case where values measured by the first thermometer and the first hygrometer are out of a predetermined range.

An air conditioner unit is configured for automatically detecting a restricted duct and adjusting fan speed schedules in response. The air conditioner unit includes an indoor fan including a drive motor for selectively rotating the indoor fan to urge a flow of air through the indoor portion and a controller is configured for sending a control signal to the drive motor to rotate the indoor fan to an actual fan speed. Based on the actual fan speed and a unit voltage, the controller obtains a target control signal, e.g., via a lookup table, and determines that a restricted duct condition exists if the control signal is different than the target control signal. The controller adjusts the operation of the indoor fan in response to determining that the restricted duct condition exists.

A controller for HVAC equipment of a plant includes a processing circuit configured to predict an impact of a time delay of the plant on a performance variable received as feedback from the plant. The processing circuit is configured to artificially increase or decrease a value of the performance variable using an adjustable time delay parameter to at least partially negate the impact of the time delay on the performance variable. The processing circuit is configured to use the artificially increased or decreased value of the performance variable in on-off feedback control to operate the HVAC equipment.