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.

A duct detector may include a detection chamber and a control circuitry stacked vertically on top of the detection chamber. A sealing gasket may seal a contact between a substrate of the control circuitry (e.g., the seal may be at the bottom surface of a printed circuit board containing the control circuitry) and the detection chamber such that particles analyzed the detection chamber may not damage the control circuitry. Therefore, by providing a sealed barrier between the control circuitry and the detection chamber, the sealing gasket allows for stacking the control circuitry and the detection chamber. As the seal does not create a barrier (the barrier is for the detection chamber) for a repair personnel to access the control circuitry, repairs to the duct detectors may be easier because the seal may not have to be broken and resealed during the repair process.

An air-conditioner includes: a return-air inlet and a supply-air outlet each communicating with a predetermined space; a first main air channel configured to allow air to flow therein towards the supply-air outlet; a first heat exchanger disposed in the first main air channel and that causes heat-exchange between refrigerant flowing therein and air passing therethrough; an exhaust-air outlet communicating with an outside of the predetermined space; a second main air channel configured to allow air to flow therein towards the exhaust-air outlet; a second heat exchanger disposed in the second main air channel and that causes heat-exchange between refrigerant flowing therein and air passing therethrough; and an exhaust ventilation channel configured to allow air to flow therein from the return-air inlet towards the exhaust-air outlet.

An indoor air cleaning system with disconnection detecting and preventing mechanism includes a gas filtration device and a cloud computing server. The gas filtration device is disposed in an indoor field and including a fan, a filter element, a gas detector and a driving control element. The gas detector detects air pollution, outputs air pollution information. The cloud computing server receives the air pollution information via IOT communication, stores the air pollution information to form a big data database, performs an intelligence computing for comparison based on the big data database, and issues a control command to enable the fan. When IOT communication is judged as disconnected, the gas detector autonomously computes and compares the air pollution information and issues the control command to enable the fan, thereby reaching a gas state of the indoor field to a cleanroom class with a level of air pollution close to zero.

An air purification device is provided. An example air purification device includes a first sensing device for sensing at least one component in an airflow along an airflow pathway. The first sensing device determines a sensor reading for the at least one component. The example air purification device also includes at least one filtration device. The at least one filtration device is positioned along the airflow pathway. The example air purification device further includes a blower. The blower is adjustable to control an amount of air flowing through the airflow pathway. A blower output of the blower is adjusted based on the sensor reading.

In some aspects, a method for scheduling a heating, ventilation and air-conditioning (HVAC) system is provided. The HVAC system includes an air conditioning plant, at least one air handling unit (AHU) in connection with the air conditioning plant, and the at least one AHU is configured to serve a plurality of zones. The method includes: obtaining zone environmental information including a zone temperature, a zone air quality indicator and zone set-points for the plurality of zones that include zone temperature set-points and zone air quality set-points. The method also includes obtaining conditioned air temperature and conditioned air quality indicator and fresh air temperature of fresh air configured to mix with return air of the conditioned air to form pre-conditioned air and determining a minimum conditioned air conditioned air supply rate and a return air ratio based on a conditioned air function of parameters including the obtained information.

An air supply system moderates excess energy consumption occurring in fans. A second unit includes a second fan that supplies first air to a target space. A duct sends the first air sent from a first unit by a first fan to the second unit. A remote sensor acting as a first detector detects information about second air in the target space. A main controller acting as a first controller communicates with the second unit and the remote sensor. The second unit includes a second detector that detects the air flow volume sent by the second fan, and a sub-controller acting as a second controller that controls the rotation speed of the second fan. The main controller determines a target air flow volume of the second unit on the basis of the information about the second air acquired from the remote sensor, and transmits an instruction indicating the target air flow volume to the sub-controller. The sub-controller controls the rotation speed of the second fan such that the air flow volume detected by the second detector approaches the target air flow volume.

Apparatuses, systems, methods, and computer program products for carbon dioxide based ventilation monitoring are described. An apparatus may include a carbon dioxide sensor, a processor, and/or a memory storing computer program code executable by the processor to perform operations. An operation may include interpolating a ventilation metric for an environment of a carbon dioxide sensor based at least partially on data from the carbon dioxide sensor using carbon dioxide as a proxy for ventilation. An operation may include performing a predefined action based on a ventilation metric.

Disclosed are methods for measuring building health index using some mandatory and set of optionally configured parameters and utilizing building monitoring system having a connection to sensors in or pertaining to a building, and including central computing environment and one or more display devices showing the measurement. A building utilizing this method may be installed with one or more sensors, and which may be communicating to a locally installed communication device or a centrally installed computing environment that can collect the measurements over a period.

--Building including a living space, separated from an outside space by an outer wall, wherein a heat exchanger unit is provided at the outer wall and wherein a ventilator is provided for forcing air through the heat exchanger unit, wherein an air outlet duct is connected to the heat exchanger unit for allowing air to be expelled from the living space through the heat exchanger, such that heat can be exchanged in the heat exchanger between air flowing into the living space and air being expelled from the living space, wherein in the living space at least one sensor unit is provided for assessment of air quality and/or noise in the living space and control of the ventilator and/or the heat exchanger unit based on the assessed air quality and/or noise level in the living space.