An air purifier system includes at least one air purifier and a portable user interface device. The user interface device for positioning at a remote location from the at least one air purifier and wirelessly communicated to a controller of at least one of the air purifiers. The user interface device includes a sensor configured to measure an air quality parameter in an area proximate the user interface device for transmission of the air quality parameter to the controller of the at least one of the air purifiers via wireless communication; and a user interface comprising (a) a display for displaying data including at least air quality data from the sensor and (b) a user input control for the user to change one or more functional parameters of the at least one of the air purifiers via the wireless communication.

A method for controlling air quality in an indoor environment of a building comprises the steps of: storing control values of carbon dioxide and/or volatile organic compound concentration; detecting an instantaneous value of carbon dioxide concentration and sending it to a control unit (5); detecting an instantaneous value of volatile organic compound concentration and sending it to the control unit (5); processing the control values and the instantaneous values of carbon dioxide and volatile organic compound concentration to generate an output signal representative of the detected air quality; sending the output signal to a visual and/or acoustic warning unit (7).

The ionizer feedback control converts high-voltage signals to feedback signals to monitor the corresponding high-voltage signals and compares the feedback signals to a first specification to determine whether the feedback signals are within the first specification. The ionizer varies a frequency and a duty cycle of a digital signal to control an excitation signal for a step-up transformer and modulates the frequency and the duty cycle of a step-up transformer output voltage to consistently maintain the feedback signals within the first specification and maintain the high-voltage signals within a second specification to generate consistent ion concentrations over a range of electrical signal inputs. The microprocessor calculates and reports high-voltage signals, and ion concentrations based on feedback signals. The microprocessor monitors concentrations of Volatile Organic Compounds (VOCs) in an airflow serving the ionizer and adjusts the high-voltage signals and ion concentration when VOC concentrations are above a threshold.

A ventilation system includes an inside air passage having inflow and outflow ends communicating with an indoor space to be ventilated, at least one permeable film unit including a permeable film, and an air supply passage having an inflow end communicating with an outdoor space and an outflow end connected to a downstream side of the permeable film in the inside air passage. The permeable film allows a target gas to pass and allows the target gas that has passed through the permeable film to be discharged into outdoor air. The target gas contains at least one of carbon dioxide and a volatile organic compound in indoor air that flows in the inside air passage. Alternatively or in addition, the ventilation system can include an outside air passage and a discharge passage in place of or in addition to the inside air passage and the air supply passage, respectively.

An air purification piece and an air purification module including same. The air purification piece includes a substrate piece and a purification coating (4), which is provided on the outer surface of the substrate piece; the substrate piece comprises a first support piece (11), a second support piece (12) and a heating component (2), which is provided between the first support piece (11) and the second support piece (12).

A system and method for remote calibration of an air-quality sensor device. The method includes receiving sensor data from at least one sensor device; analyzing the received sensor data to identify at least statistically-significant values indicating on at least drift from initial calibrated values of each of the at least one sensor device; for each identified drifted sensor device, computing re-calibration updates, wherein the re-calibration updates adjust the initial calibrated values such that readings of the respective drifted sensor device fall within a range of expected values; and transmitting the re-calibration updates to the respective drifted sensor device, wherein the respective drifted sensor device upon receiving the re-calibration updates is configured to update its calibration parameters.

A heating, ventilation and air conditioning (HVAC) unit can flow conditioned air into an indoor space through a first flow pathway, and receive returned air from the indoor space through a second flow pathway. A sensor module is positioned in the second flow pathway to receive the return air from the indoor space and determine that a quantity of volatile organic compounds (VOCs) in the return air exceeds a threshold VOC quantity. In response, the HVAC unit can flow a quantity of the return air out of the second flow pathway and into the atmosphere, and draw, into the second flow pathway, an equal quantity of air from the atmosphere. The HVAC unit can flow a remainder of the return air and the drawn quantity of air from the atmosphere into the first flow pathway to be conditioned and flowed into the indoor space.

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 improved air quality monitoring device provides accurate and reliable predictions regarding likelihood for microbial growth on building walls. The present invention comprises a housing adapted to affix the device to a building wall, a first sensor array placed in close proximity to the wall, a second sensor array and a processing means operatively connected to the first sensor array and the second sensor array. The first sensor array provides inputs such as relative humidity at the surface of the wall, the wall temperature and wall pressure. The second sensor array provides inputs such as relative humidity, temperature pressure and quality of ambient air. Using inputs from the first sensor array and the second sensor array, the processing means generates an output representative of the likelihood of microbial growth and the likelihood that the wall moisture is caused by condensation. A system of networked monitoring devices is also described.

A positive and negative oxygen ion air purification system uses dielectric barrier discharge for rail transport. The system includes: an air intake device including a first damper and second damper, wherein the first damper is in communication with the second damper; an evaporator disposed within the air intake device, wherein gas flowing through the first damper and second damper passes through the evaporator; a purification device, wherein gas flowing through the first damper and second damper passes through the purification device, wherein the purification device includes a mounting plate, a power supply module and an ion generation module, the purification device is disposed on the air intake device by the mounting plate, and the power supply module includes an input end, a transformer, and an output end; a detection device; and a control device connected to the detection device, the air intake device and the purification device.