A detector is a device that capable of detecting a property of an environment (e.g., temperature and/or humidity of a room, etc.) and/or the presence of a hazard in the environment (e.g., smoke and/or carbon monoxide (CO) in a room, etc.). A smoke detector is a type of detector that is capable of, at a minimum, detecting the presence of smoke (e.g., a smoke detector may be able to detect the presence of CO in addition to detecting smoke, etc.). A photo-electric smoke detector is a type of smoke detector that detects smoke using light reflection principles.
Conventional photo-electric smoke detectors include an optic chamber configured to receive smoke particles, at least one light emitter configured to emit light into the chamber, and at least one light receiver configured to receive light reflected off of the smoke particles in the chamber. When there is no smoke in the optic chamber, and the optic chamber is empty or mostly empty, the light receiver typically receives a small amount of light reflected from the chamber surfaces. On the other hand, when smoke is present in the optic chamber, the light receiver receives more light due to the light being reflected from the smoke particles. When an amount of light received by the receiver exceeds a certain threshold, an alarm is triggered.
Smoke detectors can be used to detect the presence of smoke in a number of different environments (e.g., both in commercial and residential buildings). For example, smoke detectors may be designed so that they can detect smoke from within a heating, ventilation, and air conditioning (HVAC) system (e.g., within a commercial building). To detect smoke within an HVAC system, smoke detectors are commonly installed within HVAC ducts. To ensure that the smoke detectors within the ducts are operating correctly, the National Fire Protection Association (NFPA) recommends that regular testing be conducted. For example, regular testing of the differential pressure between the inlet and outlet ports of the smoke detector is recommended. Typically to obtain the differential pressure reading external pressure sensors are used. However, use of external pressure sensors for testing is highly inconvenient, as the installation and later removal of the external pressure sensors is a time-consuming manual process. For example, each smoke detector being tested must be manually partially uninstalled (to place the external pressure sensor) and then later manually reinstalled (to put the smoke detector back in an operational state) by a service technician.
Depending on the size of the commercial building there may be multiple smoke detectors placed throughout the ductwork of the HVAC system. As can be assumed, it can be very onerous to complete the testing of all of the smoke detectors within the HVAC system. Additionally, with the traditional testing methods requiring a service technician, the smoke detectors may not be tested outside of the required testing periods, as the owners/tenants of the commercial building may not want to spend resources doing tests of the smoke detectors beyond what is required.
Accordingly, there remains a need for a smoke detector, and method of testing such smoke detector, that is capable of detecting smoke within an HVAC duct and has an increased ability to be regularly tested (e.g., compared to existing smoke detectors that are capable of detecting smoke within an HVAC duct).
According to one embodiment a smoke detector is provided. The smoke detector includes a housing, an emitter, a receiver, an entry point, and an exit point. The housing defines a chamber. The housing includes an inlet port and an outlet port configured to allow an airflow to pass through the chamber. The emitter is configured to emit light into the chamber. The receiver is configured to receive light reflected by ambient materials in the airflow passing through the chamber. The entry point and the exit point define a channel therebetween, at least a portion of the airflow passing through the channel. The channel is in fluid communication with a sensor. The sensor is configured to detect at least one of a pressure differential and a mass flow of the airflow.
In accordance with additional or alternative embodiments, the entry point is disposed in the inlet port.
In accordance with additional or alternative embodiments, the exit point is disposed in the outlet port.
In accordance with additional or alternative embodiments, at least one of the entry point and the exit point have a manifold configuration.
In accordance with additional or alternative embodiments, the smoke detector further includes a controller in communication with the sensor, the controller configured to trigger a notification when the sensor detects at least one of: a mass flow outside of an acceptable mass flow range, a negative pressure differential, and a negative mass flow.
In accordance with additional or alternative embodiments, the acceptable mass flow range is between 100 CFM and 4000 CFM.
In accordance with additional or alternative embodiments, the smoke detector further includes a supporting structure, at least one of the emitter, the receiver, the sensor, and the controller disposed on the supporting structure.
In accordance with additional or alternative embodiments, the supporting structure is a printed circuit board (PCB).
In accordance with additional or alternative embodiments, the smoke detector further includes an optics cover disposed between the housing and the supporting structure.
In accordance with additional or alternative embodiments, the optics cover includes a recessed area the recessed area configured to receive a channel cover, the channel defined between the recessed area and the channel cover.
In accordance with additional or alternative embodiments, the smoke detector further includes at least one O-ring disposed between the optics cover and the sensor.
In accordance with additional or alternative embodiments, at least one of the inlet port and the outlet port are configured to receive a tube.
In accordance with additional or alternative embodiments, the smoke detector is configured to detect ambient materials within an HVAC duct.
In accordance with additional or alternative embodiments, the housing includes at least one attachment point for securing the smoke detector to the HVAC duct.
In accordance with additional or alternative embodiments, the smoke detector detects ambient materials within the HVAC duct using at least one of: a multi-wave multi-angle detection method, a backscatter detection method, and a forward scatter detection method.
According to another aspect of the disclosure, a method for testing a smoke detector is provided. The smoke detector includes a controller in communication with a sensor. The smoke detector includes a housing defining a chamber. The housing includes an inlet port and an outlet port configured to allow an airflow to pass through the chamber. The smoke detector further includes an entry point and an exit point, defining a channel therebetween. At least a portion of the airflow passes through the channel. The channel is in fluid communication with the sensor. The method is performed in the controller. The method includes a step for receiving, from the sensor at the controller, output signals indicating at least one of a pressure differential and a mass flow of the airflow. The method also includes a step for determining, in the controller, whether the output signals indicate a need to trigger a notification.
In accordance with additional or alternative embodiments, the method further includes a step for triggering a notification when the output signals indicate at least one of: a mass flow outside of an acceptable mass flow range, a negative pressure differential, and a negative mass flow.
In accordance with additional or alternative embodiments, the acceptable mass flow range is between 100 CFM and 4000 CFM.
The subject matter, which is regarded as the disclosure, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The following descriptions of the drawings should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
Different agencies around the world set standards for the functional testing of smoke detectors configured within HVAC ducts. For example, Underwriter Laboratories (UL) recommends (through standard 268-A) that smoke detectors configured within HVAC ducts be functionally tested once a year. This functional testing commonly includes ensuring that the velocity of the airflow is within the proper range (e.g., between 100 and 4000 CFM for UL 268-A). It should be appreciated that each standard (e.g., set by each independent agency) may have different requirements (e.g., different velocity ranges, etc.) and/or recommended testing periods. Making sure the velocity of the airflow is within the proper range is critical to ensure that the smoke detector can accurately detect the presence of smoke. It should be appreciated that each smoke detector may be designed (e.g., by technology providers) and certified (e.g., by a certification agency such as UL) to detect smoke in an airflow with a certain range (e.g., between 100 and 4000 CFM) of velocity and, as such, it is critical that the velocity of the airflow be within the required range. The design and configuration of the smoke detector described herein has an increased ability to be regularly tested (e.g., compared to existing smoke detectors that are capable of detecting smoke within an HVAC duct), which may help ensure that the velocity of the airflow is within the proper range. It is envisioned that by making functional testing easier to complete, the functional testing may be able to be completed more routinely (e.g., more than the once a year, recommended by UL).
It should be appreciated that the smoke detector described herein may include one or more emitter(s) and one or more receiver(s) to allow the smoke detector to detect smoke. It is envisioned that the smoke detector may use at least one of: a multi-wave, multi-angle detection method, a backscatter detection method, and a forward scatter detection method. For example, the smoke detector (when utilizing a multi-wave, multi-angle detection method) may include multiple emitters configured to emit multiple kinds of light at various angles to one or more receivers, which may generate a combination of infrared forward scatter, infrared back scatter, and blue forward scatter. However, to reduce the cost and complexity of the smoke detector, the smoke detector (when utilizing a backscatter detection method) may include only one emitter and only one receiver configured to generate a backscatter effect (e.g., the emitter may be configured to emit light into a chamber where it is reflected at an angular distance less than 90° by ambient materials in the chamber toward a receiver).
Regardless of the method of detection utilized by the smoke detector, in various instances, the emitter(s) and the receiver(s) may be mounted to the upper surface of a supporting structure (e.g., a printed circuit board (PCB) or other substrate) using surface-mount technology. It should be appreciated that although the components may be mounted using surface-mount technology, in various instances, the components may be mounted through punctured holes in the supporting structure. A supporting structure may be viewed as a component of a smoke detector that mechanically supports and communicatively connects components (e.g., the emitter, receiver, and/or controller) of the smoke detector (e.g., using conductive tracks, pads, or other features etched from one or more layers of copper onto and/or between one or more non-conductive sheets).
Surface-mount technology is a method of mounting electrical components directly onto a surface (e.g., an upper surface) of a supporting structure (e.g., a printed circuit board (PCB) or other substrate). This method may provide for a solder pad (e.g., made of tin-lead, or gold plated copper) to be placed at each respective location where a component is to be mounted on the supporting structure. Additionally, the method may provide for solder paste (e.g., made of flux and solder particles) to be applied to each respective solder pad (e.g., using screen printing process, or jet-printing mechanism) before the components are mounted on the respective solder pads. It should be appreciated that alternative methods of surface mounting the components (e.g., the emitter(s) and the receiver(s)) may be utilized. For example, the components (e.g., the emitter(s) and the receiver(s)) may be mounted to the supporting structure using a plug-in connection that may or may not require solder pads and/or solder paste. To place each of the components the method may incorporate a pick-and-place machine, which may remove the need for manual placement of the components.
The ability to use the pick-and-place machine may be enabled by the design of the smoke detector. For example, the smoke detector may be designed to operate in a vertical fashion where the components (e.g., the emitter(s) and the receiver(s)) are placed and operate in a vertical fashion (instead of relying on precise horizontal angles), which may make the pick-and-place machine a viable option to use in the manufacturing process. It should be appreciated that although the components may be placed and designed to operate in a vertical fashion, in various instances, the components may be placed and designed to operate in a horizontal fashion. Regardless of how placed, once the components are placed on the supporting structure the supporting structure may be placed in a heating device (e.g., a soldering oven) to bond the components to the supporting structure. To remove excess material (e.g., flux and solder) each supporting structure may be washed before the supporting structure is configured within the smoke detector. Although the smoke detector described herein may be manufactured using a pick-and-place machine, it should be appreciated that the smoke detector may be manufactured using any suitable manufacturing method (e.g., 3D printing, etc.).
It is envisioned that regardless of the specific method of detection or manufacturing process used, the smoke detector described herein is able of being more easily functionally tested (e.g., when compared conventional duct smoke detectors) in situ without being removed or partially removed from a duct or other installed position. The smoke detector described herein incorporates a sensor capable of completing functional testing of the smoke detector, which removes the need for the installation of an external pressure sensor to complete functional testing.
With reference now to the Figures, a smoke detector 100 in accordance with various aspects of the disclosure is shown in
As shown in
Regardless of the specific type of sensor 150 used, the sensor 150 is configured to receive at least a portion of the airflow 400 that passes through the smoke detector 100 (e.g., substantially all of the airflow 400 that is passed through the channel 124). It should be appreciated that the channel 124 may viewed as a hollow body (e.g., tubing, formed plastic, etc.) that connects the entry point 122 with the exit point 123. As shown in
At least one of the entry point 122 and the exit point 123 may have a manifold configuration (as shown in
It should be appreciated that regardless of whether the point 122, 123 is disposed in a port 112, 133 or has a manifold configuration, the size (e.g., cross-sectional area covered) of the point 122, 123 may be chosen based on the amount of airflow 400 needed for sampling (e.g., by the sensor 150). For example, the entry point 122 may have a larger cross-sectional area when larger volumes of airflow 400 are needed for sampling (e.g., to detect the pressure differential and/or mass flow of the airflow 400). The required amount of airflow 400 needed for sampling may be based upon the specification (e.g., provided by the manufacturer of the sensor 150) for the particular sensor 150.
In all embodiments the smoke detector 100 may include a controller 160 in communication with the one or more sensor(s) 150 (shown in
The controller 160 may trigger a notification when the sensor 150 detects at least one of: a mass flow outside of an acceptable mass flow range, a negative pressure differential, and a negative mass flow. This notification may cause a trouble condition or an alarm to occur either on the detector 100 or remotely. It is envisioned that the trouble condition or alarm may include at least one of: an audible signal, a visual indicator (e.g., an illumination of an amber LED), and a digital signal. It should be appreciated that an acceptable mass flow range (as set by a certification agency) may be between 100 CFM and 4000 CFM, or other range set by an agency, which may be the range in which the smoke detector 100 is designed and certified to accurately detect smoke particles. In certain instances, both a negative pressure differential and a negative mass flow may indicate that the airflow 400 is going in the wrong direction (e.g., coming in the smoke detector through outlet port 113 and exiting through the inlet port 112), which may compromise the ability of the smoke detector 100 to accurately detect smoke particles.
As mentioned above, the smoke detector 100 may include a supporting structure 140 (shown in
As shown in
As mentioned above, the smoke detector 100 described herein may be particularly useful to detect ambient materials in an airflow 400 passing through an HVAC duct (not shown). As shown in
The configuration/operation of the components in the smoke detector 100 described above make it possible to complete in situ functional testing of the smoke detector 100 (e.g., without having to remove or partially remove the smoke detector 100 from a duct or other installed position to install an external pressure sensor, as is required by traditional duct detectors). For example, by integrating a sensor 150 within the smoke detector 100, the smoke detector 100 can be functionally tested in place without a service technician removing and re-installing an external pressure sensor. An exemplary method 800 for testing the smoke detector 100 is illustrated in
As shown in
The use of the terms “a” and “and” and “the” and similar referents, in the context of describing the invention, are to be construed to cover both the singular and the plural, unless otherwise indicated herein or cleared contradicted by context. The use of any and all example, or exemplary language (e.g., “such as”, “e.g.”, “for example”, etc.) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed elements as essential to the practice of the invention.
While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.
The application claims the benefit of U.S. Provisional Application No. 62/706,070 filed Jul. 30, 2020, the contents of which are hereby incorporated in their entirety.
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