Controlling a fume hood airflow using an image of a fume hood opening
The present disclosure relates generally to fume hoods, and more particularly to systems and methods for controlling a fume hood airflow using an image (e.g., an optical image, an acoustic image, etc.) of a fume hood opening. A system for controlling a fume hood may include an image capture sensor, a configurator and a controller. The image capture sensor may be positioned to have a field of view that includes at least a portion of a fume hood opening, and may be configured to capture an image that includes at least part of the fume hood opening and/or a person working at the hood. The controller may then provide a control signal to a ventilation device for providing a desired airflow in the fume hood. The control signal provided to the ventilation device may depending on the current size of the fume hood opening as captured by the image capture sensor.
1. A system for controlling a fume hood with one or more movable sashes, comprising:
an image sensor configured to provide an image, the image sensor having a field of view that includes at least part of a fume hood opening defined at least in part by the one or more movable sashes;
a configurator to store configuration information including dimensional information about the fume hood opening; and
a controller configured to calibrate the image sensor by:
obtaining first and second reference images of the fume hood opening with the one or more movable sashes at first and second specified positions; and
analyzing the first and second reference images using the dimensional information;
the controller further configured to provide a control signal to a ventilation device to produce a desired airflow in the fume hood, wherein the controller uses an image of the fume hood opening provided by the calibrated image sensor to generate the control signal.
2. The system of claim 1 , wherein the desired airflow is determined as a function resulting in airflow per unit of area of the fume hood opening.
3. The system of claim 1 , wherein the sensor comprises an infrared light sensor to provide an infrared image of the fume hood opening.
4. The system of claim 1 , wherein the sensor comprises a visible light sensor to provide a visible light image of the fume hood opening.
5. The system of claim 1 , wherein the sensor comprises an infrared light sensor to provide an infrared image of the fume hood opening and a visible light sensor to provide a visible light image of the fume hood opening.
6. The system of claim 1 , wherein the configurator comprises:
a graphical user interface for a user to enter identification information about the fume hood; and
a memory for storing dimensional information about one or more different fume hoods; and
wherein the configurator prompts the user via the graphical user interface to adjust one or more of the movable sashes to obtain the first and second reference images.
7. The system of claim 1 , wherein a geometrical shape of the fume hood opening is adjustable using the one or more movable sashes, the sashes being mechanically coupled to the fume hood.
8. The system of claim 7 , wherein a position of the one or more movable sashes is capable of being vertically and/or horizontally adjusted relative to the fume hood opening.
9. The system of claim 1 , wherein the sensor is located within the fume hood.
10. The system of claim 1 , wherein the sensor is located outside of the fume hood.
11. The system of claim 1 , wherein the controller is configured to detect at least one edge of the fume hood opening using the image of the fume hood opening from the calibrated image sensor to determine a measure related to a size of the fume hood opening and to calculate the desired airflow based at least in part on the determined measure related to the size of the fume hood opening.
12. The system of claim 11 , wherein the controller is configured to determine the measure related to the size of the fume hood opening using the image of the fume hood opening received from the calibrated image sensor, wherein the image of the fume hood opening is at least partially obstructed by an object.
13. The system of claim 1 , wherein the controller identifies the presence and/or absence of a person at or near the fume hood opening using the image of the fume hood opening obtained from the calibrated image sensor.
14. The system of claim 13 , wherein the controller identifies whether the person at or near the fume hood opening is moving past the fume hood opening.
15. The system of claim 13 , wherein the fume hood is installed in a room and/or zone of a building and the controller identifies whether one or more lights are off within the zone using the image of the fume hood opening obtained by the calibrated mage sensor; and
after identifying an absence of a person at or near the fume hood opening, the controller issues an alarm when the lights are off for a specified duration and the fume hood is at least partially open.