A system includes one or more occupancy sensors, one or more environmental sensors and one or more controllable building components. A controller is configured to receive occupancy signals from the one or more occupancy sensors over a building network and to receive indoor air quality parameter signals from the one or more environmental sensors over the building network and to process the received signals to determine whether action is needed to improve one or more environmental conditions within at least some of the plurality of building spaces to reduce the likelihood of disease transmission among occupants of the building. Responsive to determining that action is needed, the controller is configured to provide control signals to one or more of the controllable building components over the building network to improve one or more environmental conditions within at least some of the plurality of building spaces.

An air conditioner at least including a controller, a first fan unit, and a second fan unit arranged parallel to the first fan unit is disclosed. The controller performs a parallel operating control procedure, including a first control mode and a second control mode, to the first fan unit and the second fan unit respectively. When operating under the first control mode, the controller adjusts the rotating speed of one of the first fan unit and the second fan unit based on a first standard air volume, so the two fan units output the air volume equal to or approximate to the first standard air volume. When operating under the second control mode, the controller controls the rotating speed of both the first and second fan units according to a second standard air volume, so the two fan units output the same air volume.

The invention relates to a particle protection device (32) for a dehumidifier (1), the dehumidifier (1) comprising: a dehumidifying element (2), configured to separate moisture from air; a filter element (22) for separating particles from a process airflow (8); and a process air fan (20) for generating the process airflow (8) through the dehumidifying element (2) and through the filter element (22). Wherein the particle protection device (32) comprises: a control device (100); and a particle detector (30) arranged in communication with the control device (100) and configured to be arranged at the dehumidifier (1) to determine the particle concentration in the air that surrounds the dehumidifier (1) and that should be processed by the dehumidifier (1). The invention also relates to a method, performed by a control device (100) of a particle protection device (32), for protecting a dehumidifier (1) from particles. The invention also relates to a dehumidifier (1). The invention also relates to a computer program (P) computer-readable medium.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for monitoring an HVAC system. One of the methods includes receiving pressure data from one or more sensors monitoring a supply air duct of an HVAC system at a property that indicates a pressure in the HVAC system; determining, using the pressure data, that the pressure satisfies a pressure threshold for the HVAC system; and in response to determining that the pressure satisfies the pressure threshold, adjusting an actuator-controlled damper between the supply air duct and a return air duct or adjusting a fan speed of the HVAC system.

A control method for an air conditioning system. The control method includes: S100, acquiring an actual cooling/heating capacity output by the air conditioning system, and acquiring an actual temperature change rate of an indoor heat exchange unit; S200, automatically learning a heat exchange load characteristic curve of the indoor heat exchange unit based on the actual cooling/heating capacity and the temperature change rate; S300, acquiring a steady state load and/or a desired load of the indoor heat exchange unit based on the heat exchange load characteristic curve; and S400 adjusting the number of operating compressors and rotational speeds of compressors, and/or adjusting the number of operating injectors and opening degrees of injectors, based on the steady state load and/or the desired load.

An air conditioner, and a method of controlling the air conditioner, including a compressor configured to compress a refrigerant, and including a discharge port; an outdoor heat exchanger configured to exchange heat with outside air, and including an upper portion including an upper inlet, and a lower portion including a lower inlet; a first four-way valve arranged between the discharge port of the compressor and the upper inlet; a second four-way valve arranged between the discharge port of the compressor and the lower inlet; and a controller electrically connected to the compressor, the first four-way valve and the second four-way valve. The controller may be configured to control the first four-way valve and the second four-way valve to perform a first defrosting operation which defrosts the upper portion and the lower portion during a heating operation, and control the first four-way valve and the second four-way valve to perform a second defrosting operation which operates the upper portion as an evaporator, and operates the lower portion as a condenser, based on a need for additional defrosting of the lower portion being detected.

There is described a controller and method for managing a flow unit. A measured full flow corresponding to a full open position of a flow control element of the flow unit is detected. A calibration nominal is established based on the measured full flow, and calibration relative flows are calculated based on the calibration nominal and calibration measured flows corresponding to calibration positions of the flow control element. Subsequent to calibration, an operation measured flow of the flow unit and an operation position of the flow control element are detected. A dynamic nominal is determined based on the operation measured flow and a particular calibration relative flow corresponding to the operation position of the flow control element. An operation relative flow and a relative flow setpoint are determined based, in part, on the dynamic nominal. The operation position of the flow control element is controlled based the operation relative flow and relative flow setpoint.

An HVAC system includes a suction-side sensor, a liquid-side sensor, an outdoor temperature sensor, and a controller. The controller determines that initial criteria are satisfied for initiating validation of the suction-side sensor and the liquid-side sensor. After determining that the initial criteria are satisfied, a suction-side property value, liquid-side property value, and outdoor temperature value are received. The controller determines whether a first validation criteria and a second validation criteria are satisfied. If both the first validation criteria and the second validation criteria are satisfied, the suction-side sensor, the liquid-side sensor, and the outdoor temperature sensor are determined to be functioning properly. Otherwise, the controller determines which one or more of the sensors are malfunctioning.

A pressure probe includes a tube having an output end, an internal passage, an axial run, and pressure orifices axially aligned along a downstream side of the axial run. The pressure orifices are in communication with the output end through the internal passage and an upstream side of the axial run that is opposite from the downstream side of the axial run and does not include a pressure orifice. The downstream side is perpendicular to airflow.

A three-pipe multi-split system. The three-pipe multi-split system includes an outdoor unit, a plurality of indoor units, and a plurality of hydraulic modules connected respectively by air pipes, liquid pipes, and condensate water pipes. The outdoor unit includes a compressor, a high-pressure pressure sensor, an oil separator, a first switching device, a second switching device, a third switching device, a finned heat exchanger, a compressor heat dissipation module, a plate type heat exchanger, a first electronic expansion valve, a second electronic expansion valve, a filling needle valve, an air-liquid separator, a low-voltage switch, a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve, a fourth electromagnetic valve, a fifth electromagnetic valve, an outdoor unit fan, and an outdoor unit temperature detection subassembly; each indoor unit includes an indoor unit heat exchanger, a third electronic expansion valve, an indoor unit fan, and an indoor unit temperature detection subassembly.