PRIORITY/CROSS-REFERENCE TO RELATED APPLICATIONS
This application hereby incorporates, by reference, U.S. Pat. No. 5,261,857, entitled, “Ceiling Vent with Movable Vane.”
FIELD OF THE INVENTION
This invention relates to an improvement in a ceiling vent for dispersing airflow into a room. More particularly, the invention relates to an airflow measurement system for determining outflow from a ceiling vent for adjusting the ceiling vent outflow level.
BACKGROUND OF THE INVENTION
Perhaps the most critical component of a heating or cooling system in a home or office is the vent or diffuser for dispersing the heated or cooled airflow as evenly as possible throughout the room. If diffusion of the airflow throughout the room is uneven, then pools of air of different temperatures may form at various locations in the room. This is an inefficient way to heat or cool a room and can be uncomfortable to persons who live or work there.
The best known way to diffuse airflow in a room is to redirect the airflow in a laminar flow at the top of the room. This sheet of airflow then mixes with the ambient air to achieve relatively even heating or cooling without pooling or dumping in certain locations. The distance that airflow moves at a given velocity, or airflow throw, will vary with the velocity of the airflow that moves through a vent. Thus, differences in velocity will affect the evenness of air dispersion in a room. It is highly desirable to maintain constant the airflow throw from a vent, despite variations in initial airflow velocity, to control the even mixing of airflow in a room. A fluid, such as a current of airflow that is moving at some velocity along an adjacent surface tends to cling to that surface. This is because low pressure is created below the current, in the case of a stream of airflow moving along a ceiling, thus lifting the current of airflow upward against the ceiling. This phenomenon, the Coanda effect, increases the airflow throw and thus, the dispersion of air in a room.
One proposal for maintaining even mixing of airflow from a ceiling diffuser involved a device mounted on conventional ceiling tee bars and containing a thermostatically controlled motor to position airflow control vanes to manage variable flows of conditioned air (U.S. Pat. No. 3,848,799). Another device handled variable airflow by pumping air into a bladder to regulate the area of air discharge (U.S. Pat. No. 3,434,409). Other devices of general interest had to be manually adjusted to handle different airflows (U.S. Pat. Nos. 4,475,446 and 4,008,653). These devices all suffer the disadvantages of mechanical complexity or the need for manual adjustment to handle variations in airflow.
Accordingly, applicant and co-inventors invented the device disclosed in U.S. Pat. No. 5,261,857, entitled “Ceiling Vent with Movable Vane”. The vane of that invention is normally biased toward an airflow catch which comprises a partition also positioned in the path of inflowing airflow to redirect and laterally diffuse airflow within the plenum. When there is no flow of airflow through the vent, the vane is disposed against the airflow catch to close the airflow discharge aperture. When airflow flows through the vent, the vane is moved away from the airflow catch by the force of the moving airflow to variably adjust the width of the airflow discharge aperture. Both the movable vane and the airflow catch are curved to redirect the flow of airflow in a horizontal direction as it leaves the vent. The airflow catch also circulates airflow within the plenum to disperse it toward the edges of the airflow current and homogenize the current velocities.
The problem associated with the applicant's previous invention is that, in order to calibrate the system of ceiling vents found in U.S. Pat. No. 5,261,857, a vent adjuster or a team of vent adjusters would be required to come and calibrate each of the vents individually. In order to do this, a hood is typically required to be put over each of the vents in order to calibrate the amount of air flowing out of the vent. This was relatively expensive and required time to calibrate the system. Accordingly, a system is needed that reduces the amount of time and money to calibrate the system and allows for easier calibration and recalibration of the system after the system is installed.
SUMMARY OF THE INVENTION
Accordingly, an improved ceiling vent having an airflow measurement system for dispersing airflow into a room in laminar flow with respect to the ceiling of the room has been invented. The airflow is typically within a ventilation system of a building. The ceiling vent has a vent housing configured to be mounted in a ceiling. The vent housing defines a plenum on the inside of the housing. The vent housing has at least two openings; at least one of the openings allows for air to flow into the plenum of the vent housing and at least one of the openings allows air to flow out of the airflow vent in laminar flow along the ceiling of the room in which the vent is mounted. The vent has a vane that generally has a concave curvature along its length. The vane is hingedly attached to the interior of the vent housing such that the vent moves in reaction to airflow flowing through the plenum of the vent. The vane is configured to be reversibly responsive to the airflow against the concave curvature of the vane and into the plenum. This varies the size of the opening into the room with the movement of the vane by the airflow while maintaining a curved flow path discharging the airflow in laminar flow along the ceiling. The airflow measurement system is positioned and configured such that when the vane position responds to airflow through the vent, the airflow measurement system indicates the outflow level of airflow out of the vent such that the vent can be calibrated to distribute a prescribed amount of airflow into the room. The airflow measurement system comprises a calibrated scale having airflow indicia in one embodiment. Furthermore, the calibrated scale can be located such that the vane points to one of the airflow indicia on the calibrated scale when airflow travels out of the second opening in the vent housing.
The vent can also have an airflow catch such that the airflow catch partitions airflow traveling from the inflow opening in the vent housing toward the second opening. This facilitates mixing of airflow in the plenum. Additionally, the moveable vane can be configured to be calibrated to define airflow through the plenum. The ceiling vent can also have a means for biasing the moveable vane toward the vent housing. This means for biasing the moveable vane can comprise a spring or weight attached to the movable vane that biases the vane toward the generally closed position. The second opening can comprise a wide variety of opening shapes; in one embodiment it comprises a slot in the bottom wall of the housing.
The purpose of the Abstract is to enable the public, and especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection, the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
Still other features and advantages of the claimed invention will become readily apparent to those skilled in this art from the following detailed description describing preferred embodiments of the invention, simply by way of illustration of the best mode contemplated by carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiments are to be regarded as illustrative in nature, and not as restrictive in nature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a ceiling vent having a movable vane, an airflow catch, and an airflow measurement system mounted in a suspended ceiling, in accordance with the present invention.
FIG. 2 shows an end elevational view of a ceiling vent having a movable vane, an airflow catch, and an airflow measurement system mounted in a suspended ceiling, in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.
Referring to the drawings, FIG. 1 shows a ceiling vent 10 mounted in a suspended ceiling 12. The ceiling vent 10 is not limited to mounting in suspended ceilings, however, and may be mounted in other ceilings, such as a gypsum board ceiling 14 as in FIG. 2. The ceiling vent 10 comprises a plenum 16 and a housing 18. The housing 18 may be insulated to minimize changes in temperature of the airflow as it flows through the ceiling vent 10. In the preferred embodiment, a wall of the housing 18 has an opening 20 through which a current of heated or cooled airflow 22a and 22b enters the plenum 16 from an airflow and plenum source. Connected to and extending outward from the housing 18 and surrounding the opening 20 is a sleeve 24 for connecting the ceiling vent 10 to a duct that conducts heated or cooled airflow from the source.
Attached to the inside of the housing 18 is a movable vane 26 which is an elongate curved sheet that is hingedly suspended at one end of the moveable vane from the housing 18 at a hinge point 28. This vane 26 is positioned in the housing to receive the force of the inflow of airflow into the plenum 16. The bottom of the housing 18 contains a slot 30 from which airflow exits the ceiling vent 10.
Continuous with an edge of the housing 18 adjacent to the slot 30 is a curved airflow catch 32. This airflow catch 32 is a partition or sheet curving upwardly and toward the opening 20 in the housing 18. The airflow catch 32 is also positioned in the path of incoming airflow. The juxtaposition of the vane 26 and airflow catch 32 forms a flow path or passage between the vane 26 and airflow catch 32 toward the exit opening 30. Part of the airflow 22a goes directly into this flow path, while part 22b is diffused by circulation along the airflow catch and then into the flow path. This redistributes airflow to the edges for unifying the current velocities.
The hinge point 28 of the movable vane 26 is positioned so that gravity normally biases the vane 26 toward the airflow catch 32. Other methods of biasing the vane 26 toward the airflow catch 32 are by springs or weights which impose a comparable biasing load to that of gravity. If no airflow is flowing through the ceiling vent 10, then the vane 26 is in a closed position 34 in contact with the airflow catch 32. When airflow moves into the vent 10 from a source, the force of moving airflow moves the vane 26 away from the airflow catch 32. Depending on the velocity of the airflow, the vane 26 will move to a fully open position 36 or to any intermediate position 38 between fully open 36 and closed 34. The curved shape of the vane 26 redirects airflow as it flows through the vent 10 for laminar flow along the ceiling.
The distance between the bottom edge of the movable vane 26 and the curved surface of the airflow catch 32 defines an opening 40 of variable width through which airflow exits the vent 10 to the room. The width of the opening 40, as determined by the extent of deflection of the curved vane 26 in response to the force of inflowing airflow, regulates the velocity of outflowing airflow. Not only is the velocity of outflowing airflow regulated by the vent 10, but the outflowing airflow is directed by the interaction of the concave side of vane 26 and convex side of airflow catch 32 in a laminar flow along the ceiling of the room. As noted in the figures, the concavity of the vane 26 and the convexity of the airflow catch 32 are continuous along the passage sides of the respective vane and catch and up to the opening 40.
The airflow catch 32 diffuses and disperses the current of airflow that enters the ceiling vent 10, especially the airflow that enters at lower levels in the current, such as at 22b. The airflow catch 32 splits this airflow off and circulates it within the plenum and disperses it laterally, as depicted by dashed line 22b. The curved configuration of the airflow catch 32 generates a circular flow path within a forward portion 35 of the plenum, and then upward to the primary flow path 22a. The airflow that is thus circulated by the airflow catch 32 rejoins the upper level current of airflow 22a, is redirected by the movable vane 26, and exits the vent in a generally horizontal direction along the top of the room. The airflow catch 32, by dispersing airflow laterally within the vent 10 makes the velocity of outflowing airflow constant across the cross section of outflowing airflow instead of faster at the center of the outflow than at the edges. Further, airflow flow rates are increased by this homogenization of outflowing air.
In the embodiment of FIG. 1 the airflow measurement system comprises a calibrated scale 54 attached to the end plate of the vent housing such that when the vane 36 moves in response to airflow through the plenum of the vent and out the second opening the tip 56 of the vane indicates on the calibrated scale the amount of air that is flowing out the bottom of the vent. The system can subsequently be calibrated to distribute a predetermined amount of airflow into a room. For example, one method of accomplishing this would be to adjust the hinge 28 to stop at a certain set point at which a prescribed amount of airflow would enter the room. The airflow measurement system 54 can comprise a wide variety of systems that are known in the art. Airflow measurement systems generally include the illustrated calibrated scale attached to the vent housing, a similar calibrated scale attached to the vane such that, when the vane moves in response to airflow, a separate stationary pointer points to the airflow level on the calibrated scale, or any variety of digital or mechanical airflow measurement systems.
FIG. 2, illustrates the vent 10 comprises a housing 18 that defines a chamber 16 through which airflow may pass from the plenum source into the room. FIG. 2 illustrates an embodiment of the airflow measurement system 54 comprising a calibrated scale attached to the vent housing. The airflow measurement system can be attached in a wide variety of positions on the vent housing including on the airflow catch 32, the moveable vane 36, the endplate of the vent housing 56, or any location where it functions to measure airflow out of the ceiling vent.
The housing 18 contains an inlet opening 20 for supplying airflow to the chamber 16. Coupled to the inlet opening 20 are means 24 for attaching a conduit connecting the vent 10 to the plenum source. In the preferred embodiment, these means are a sleeve 24. Hingedly attached to the housing 18 within the chamber 16 is a vane 26 which may rotate about a rotational axis 28 and is positioned in the intended flow path of airflow 22a and 22b entering the chamber 16 through the inlet opening 20. The vane 26 exerts a deflecting resistance against the entering airflow 22a and 22b which causes rotation of the vane 26 to a variable degree in response to the velocity of the entering airflow 22a and 22b. The vent 10 also comprises an outlet opening 30 within the housing 18. This outlet opening 30 is positioned to receive airflow from the vane 26 and its opening size varies with the degree of rotation of the vane 26 in response to changing velocities of the entering airflow 22a and 22b. The outlet opening 30 is sufficiently small to provide a change in velocity to airflow as it exits the outlet opening 30. The invention also comprises means 32 associated with the vane 26 and outlet opening 30 for directing airflow and causing initial laminar flow of airflow exiting the outlet opening 30. In the preferred embodiment, these directing means 32 define an airflow catch 32.
To illustrate how this ceiling vent 10 tends to maintain constant the airflow throw of airflow currents of varying velocities, comparison with a vent of fixed aperture is useful. High-velocity airflow moving through an aperture of fixed width will accelerate as it travels through the aperture. Thus, not only does the airflow enter the vent at high velocity, but it is accelerated as it exits. Low-velocity airflow moving through the same aperture may accelerate as it moves through the aperture as well, but the acceleration will be less than that of the high-velocity airflow. Thus, the difference in velocities of the high-velocity airflow and low-velocity airflow is increased after moving through the fixed aperture.
In contrast, the difference in velocity of high-velocity airflow and low-velocity airflow decreases after moving through a variable aperture that is responsive to the flow rate of airflow. Acceleration of the high-velocity airflow through the variable aperture will be less than it would have been through a fixed aperture because the aperture will widen in response to the force exerted by the high-velocity airflow against the movable vane 26. A limiting flange 37 blocks further movement rearward and sets the maximum size of the outlet. Also, acceleration of the low-velocity velocity airflow through the variable aperture will be more than it would have been through a fixed aperture because the aperture will narrow in response to the lower force exerted by the low-velocity velocity airflow against the movable vane 26. Thus, a ceiling vent 10 with a movable vane 26 to vary the aperture through which airflow exits to the room, tends to maintain a more constant velocity of exiting airflow and, hence, a more constant airflow flow throw.
While there is shown and described the present preferred embodiment of the invention, it is to be distinctly understood that this invention is not limited thereto, but may be variously embodied to practice within the scope of the following claims. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims. For example, although the disclosure refers to the vane being in a generally closed position when airflow is not flowing through the vane, the generally closed first position is the ideal position for the vane to be in when no airflow is flowing through the system. The first position is not required to be completely closed and is the relative description of the vane in the position without airflow flowing through the vent housing.