A fan unit reduces the number of man-hours for a preliminary test and eliminates the need for a trial run at the time of duct connection are realized. A second controller acquires: a rotation speed of a fan motor of a second fan; a volume of air, a wind speed, or front-rear differential pressure of the second fan; and an air volume target value or a wind speed target value for the second fan, and calculates a rotation speed target value Ny for the fan motor 31b by using a first function: Ny=(Qy/Qx).sup.2??Px?{m?(Qy/Qx)?Vx+p}+n?(Qy/Qx)?Vx+q. Furthermore, when the front-rear differential pressure fluctuates and the wind speed is decreased from Vt to V, the second controller calculates a rotation speed change amount to the rotation speed target value by using a second function: ?N=a?(Vt?V).

The present disclosure is directed to an air filter sensor system that can monitor a status of a filter and provide information to a remote system regarding the filter's status. The system can receive, by a computing server via one or more computer networks and from each of a plurality of sensor assemblies coupled to a corresponding plurality of air filters, information indicative of filter contamination levels respectively associated with each corresponding air filter of the plurality of air filters. Each of the respective filter contamination levels being provided by one sensor assembly of the plurality of sensor assemblies based at least in part on a difference in detected air pressure between first and second sides of the corresponding air filter. The system tracks the respective filter contamination levels over a first period of time and determines, by the computing server and based at least in part on the tracking of the respective filter contamination levels, a schedule for one or more maintenance events associated with a first air filter of the plurality of air filters.

Systems for controlling an exhaust gas fan system. The control system may control one or more components of the exhaust system to optimize system performance and improve energy efficiency. The control system may be designed to maintain a substantially constant pressure in the exhaust header and provide a substantially constant flow through the exhaust fans. The control system is configured to control one or more of: modulation of one or more by-pass dampers; adjustment of the nozzle outlet area; varying the speed of the fans; the number and staging of fans.

An active airflow inhibiting apparatus for an entranceway comprises a structure, an airflow sensor, and a controller. The structure comprises one or more air mover devices configured to be positioned adjacent an entranceway of a building and defining a passage therethrough for accessing the entranceway. The airflow sensor is configured to provide an output indicative of speed and direction of airflow through the entranceway or at the air mover devices. The controller is connected to the air mover devices and the airflow sensor. The controller is configured to receive the output of the airflow sensor and to control an output of the air mover devices based on the received output so as to generate a differential pressure across the air mover devices which inhibits airflow through the entranceway.

A solid-state sensor, including an enclosure having a first opening in a first side of the enclosure and a second opening in a second side of the enclosure, a first passageway in fluid communication with the first and second openings, and a solid-state direction sensor positioned within the first passageway. The solid-state direction sensor can include a first sensor positioned at a first axial position, a second sensor positioned at a second axial position, and a flow deflector positioned at a third axial position that is between the first and second axial positions. The flow deflector can extend into the first passageway so as to constrict the first passageway.

An air volume control valve capable of accurately measuring an air volume is provided. The air volume control valve includes a round-shaped valve body, and a valve blade and an orifice plate provided in the round-shaped valve body, where the orifice plate is located upstream of the valve blade; an upstream pressure tapping port and a downstream pressure tapping port are respectively provided upstream and downstream of the orifice plate; a distance from both the upstream pressure tapping port and the downstream pressure tapping port to the orifice plate is 0.5 times a valve diameter; the valve blade is located downstream of the downstream pressure tapping port; an inlet side of the round-shaped valve body is provided with a convergent duct fitting; and the convergent duct fitting is located at a distance of once the valve diameter upstream of the orifice plate and is tapered along an air flow direction.

An airflow sensor assembly for an air duct is provided. The airflow sensor assembly includes the air duct having an interior wall and an exterior wall, a high pressure pickup device, a low pressure pickup device, a pressure redirection device, and a pressure sensor. The pressure redirection device is fluidly coupled to the high pressure pickup device and the low pressure pickup device and includes a low inlet, a high inlet, and a common outlet. The pressure sensor is selectively fluidly coupled to the high pressure pickup device and the low pressure pickup device and includes a first inlet and a second inlet. The second inlet is fluidly coupled to the common outlet of the pressure redirection device.

A manifold assembly includes a body and a damper assembly. The body defines a first opening, a second opening, outlet third opening, and a fluid plenum. The fluid plenum fluidly couples the first opening, the second opening, and the third opening. The damper assembly includes a first damper, a second damper, and a connecting member. The first damper is disposed within the fluid plenum proximate to the first opening. The second damper is disposed within the fluid plenum proximate to the second opening. The connecting member is coupled to both the first damper and the second damper and is configured to move the first damper and the second damper to selectively open one of the first opening or the second opening while closing the one not opened.

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.

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.