Methods and apparatus for an exhaust demand control system for measuring one or more contaminants at one or more exhaust locations within one or a plurality of exhaust ducts or plenums served by an exhaust fan system. Example systems and methods can include sensing the one or more contaminants within the one or more exhaust duct locations using a multipoint air sampling system having one or more sensors and comparing contaminant concentration measurements from the one or more of said exhaust duct or plenum locations against an action level to create a fan setback signal.

An air-conditioning system includes: an air conditioner including a refrigerant circuit formed by connecting an outdoor unit and a plurality of indoor units together, the air conditioner being configured to condition air in a plurality of indoor spaces; at least one countermeasure device provided in correspondence with at least one of the plurality of indoor spaces and configured to operate during leakage of a refrigerant; a plurality of detectors configured to detect a concentration of the refrigerant, at least one of the detectors being provided in each of the plurality of indoor spaces; and a control unit configured to operate all of the at least one countermeasure device if at least one of the concentrations of the refrigerant respectively detected by the plurality of detectors exceeds a predetermined value.

An indoor air quality control method using an intelligent air cleaner is disclosed. An indoor air quality control method using an intelligent air cleaner according to an embodiment of the present invention can predict indoor dust concentration progress on the basis of output values of a learning model having received dust concentration data as input values when the dust concentration data of an indoor place where the air cleaner is located is received from the air cleaner, and determine whether ventilation is required by comparing the predicted progress with outside dust concentration data received from the Meteorological Administration server. Accordingly, indoor dust concentration changes can be predicted and an appropriate ventilation time can be recommended. The intelligent air cleaner and the indoor air quality control method using the same of the present invention can be associated with artificial intelligence modules, devices related with the 5G service, and the like.

An HVAC system within a building including an HVAC device having an air filter, a number of sensors, and a control device. The control device has a processor that is configured to determine a current air quality metric based on air quality measurements received by the sensor. The control device is further configured to calculate an average air quality metric based on the current air quality metric and a set of previous air quality metrics. The control device is further configured to store the average air quality metric. The control device is further configured to generate an air filter type recommendation based on the average air quality metric.

An environment control system utilizes oxygen and humidity control devices that are coupled with an enclosure to independently control the oxygen concentration and the humidity level within the enclosure. An oxygen depletion device may be an oxygen depletion electrolyzer cell that reacts with oxygen within the cell and produces water through electrochemical reactions. A desiccating device may be g, a dehumidification electrolyzer cell, a desiccator, a membrane desiccator or a condenser. A controller may control the amount of voltage and/or current provided to the oxygen depletion electrolyzer cell and therefore the rate of oxygen reduction and may control the amount of voltage and/or current provided to the dehumidification electrolyzer cell and therefore the rate of humidity reduction. The oxygen level may be determined by the measurement of voltage and a limiting current of the oxygen depletion electrolyzer cell. The enclosure may be a food or artifact enclosure.

An air-conditioning system includes: an air conditioner including an outdoor unit and a plurality of indoor units each provided in a corresponding one of a plurality of indoor spaces and each including a first control unit; and a second control unit capable of communicating with the first control units. Each first control unit is capable of communicating with a countermeasure device if the countermeasure device is installed in correspondence with one of the indoor spaces where the first control unit is located. The second control unit has a first function of prohibiting operation of the air conditioner if a first condition where communication between the first control unit and the countermeasure device is not established in any of the indoor units is satisfied.

Implementations are directed to a smart filter apparatus including an air filter, a sensor supported by the air filter and sensitive to a pathogen, and a control unit in data communication with the sensor and operable to perform operations including receiving, from the sensor, an indication of the pathogen present in air incident on the sensor, generating, by the control unit, a pathogen alert response, and providing, by the control unit, the pathogen alert response.

The present invention provides a heating, ventilation, and air-conditioning (HVAC) system using an A2L refrigerant and a method of installing the HVAC system in a building. The HVAC system includes an indoor unit having a heat exchanger that uses an A2L refrigerant, a blower, an outdoor unit, an A2L control board, and one or more A2L sensors configured to detect an amount of A2L refrigerant. In one or more embodiments, the indoor unit is electrically coupled to the blower, the A2L control board, and the outdoor unit. Also, in one or more embodiments, the A2L control board is also electrically coupled to the blower and the one or more A2L sensors.

An air purifier includes a main body having an inlet and a discharge device mounted on the main body and configured to receive air introduced into the main body through the inlet and discharge the air from the air purifier, wherein the discharge device includes a discharge opening, an opening and closing member including a portion having a size and shape corresponding to the discharge opening, and configured to move out of the discharge opening and into the discharge opening to open and close the discharge opening, and a discharge portion including a plurality of discharge holes, wherein each discharge hole of the plurality of discharge holes has a size smaller than a size of the discharge opening, and wherein the discharge portion has an air discharging area that is variable.

A refrigerant leak sensor includes: a first refrigerant sensor element configured to, when powered: measure a first amount of the refrigerant present in air; and generate a first output based on the first amount; a second refrigerant sensor element configured to, when powered: measure a second amount of the refrigerant present in air; and generate a second output based on the second amount; a first selection module configured to: during a first period, apply power the first refrigerant sensor element and not apply power to the second refrigerant sensor element; and during a second period after the first period, apply power to the second refrigerant sensor element and not apply power to the first refrigerant sensor element.