The invention relates to building climate control. More particularly, the invention relates to climate control for building spaces subject to wall heating.
Localized wall heating of building spaces may have several causes. Exemplary heating may include solar heating and heating from sources internal to the building.
An exemplary solar heating involves light 42 passing through the front wall and/or ceiling to be received by the front surface/face 44 of the back wall 28. The sunlight thus heats the back wall. The heated back wall induces an upward airflow 46 along the back wall. Upon reaching the ceiling 26, the flow passes forward along the roof and then downward along the interior surface/face of the front wall. Upon reaching the floor 32, the airflow 46 may return rearward.
The resulting recirculation of the flow 46 may cause excessive heat to build-up in the space. Addressing this heat build-up may pose loads upon the building's air conditioning system.
One aspect of the disclosure involves a building having an interior space, a first wall surface, and a vent. A vortex guide baffle is positioned at least partially separating a vortex chamber from a remainder of the interior space. The vent is along the vortex chamber. The vortex chamber has an inlet opening from the remainder at the wall.
In various implementations, the building may have one or more windows positioned to admit sunlight to the interior space to heat the wall to induce an upward airflow along the wall. The vortex guide baffle may be positioned to redirect the upward flow to form a vortex. The vortex may convey the air to exit the vent. The vent may comprise first and second lateral vents proximate first and second ends of the wall. The vortex guide baffle may be positioned to redirect the upward flow to form first and second vortices respectively conveying the air to the first and second lateral vents.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
Like reference numbers and designations in the various drawings indicate like elements.
The exemplary vortices are generated/trapped by a guide baffle 70 (
The vents 54A and 54B form an exemplary outlet from the trapped space/chamber 72 in the first mode of operation. There is also at least one inlet. The illustrated inlet 74 is a single inlet extending the length of the back wall. The exemplary baffle 70 extends both vertically and horizontally. The exemplary baffle construction has an L-shaped section. An exemplary leg 76 of the L extends generally vertically and an exemplary foot 78 of the L extends generally horizontally. The exemplary inlet is between the end 80 of the baffle foot and the front surface of the back wall.
In the first mode of operation, as the airflow 46 passes up the back wall along the length thereof, the airflow passes through the inlet 74 into the chamber 72. The chamber 72 may have a combination of two effects. First, the confinement associated by the chamber directs the flow laterally toward the outlets. In the exemplary symmetric configuration, this involves an effective lateral split of the flow in mirror images relative to the centerplane 500. Additionally, the momentum of the flow, upon encountering the ceiling (chamber top) is to be turned (i.e., counterclockwise as viewed in
In certain situations, the warm air recirculation through the interior space 22 may be desirable. For example, in the winter, the heating may advantageously replace or supplement active heating systems. Accordingly, the system may be configured to shift between the first mode wherein the trapped vortex encourages air and heat discharge and a second mode wherein there is either no trapped vortex or the effect of the trapped vortex is, somehow, reduced. In one example, the mode change may be associated with articulation of the baffle 70. The mode change may alternatively or additionally be associated with opening/closing of the vents 54A and 54B.
The articulation (e.g., of the leg 76) may be manual or driven by an actuator 90 (e.g., an electric motor, pneumatic actuator, hydraulic actuator, or the like). The actuator may be controlled via a control system 100 (
In one example, the mode may be seasonally switched: the vortex venting first mode during the summer; and the second mode during other seasons. Time-of-day may also be used: the vortex venting mode during the significant insolation hours; and the second mode otherwise. As noted above, sensor-dependent operation is also possible.
The first and second modes may be further divided. For example, the second mode may be divided into: one mode with fan-forced non-vortex venting; and another mode with no venting.
In an exemplary implementation, heat removal may be greater in the vortex venting mode than in the fan-forced non-vortex venting mode (e.g., with fan operational parameters being constant, but not necessarily so). The transfer of heat out of the interior space provided by the system may exceed the heat transfer that would be provided by similarly-placed vents (and AHUs) alone even relative to mass flow and even if mass flow were decreased. For example, the AHUs and vents alone, a cooler overall mixture of air may be vented, including greater amounts of airflow drawn: rearward along the ceiling; and from the center of the atrium. The vortex venting mode biases the vented air to be preferentially drawn from the particularly warm upward flow along the back wall. This may allow the vortex venting mode to remove more heat with the same or lesser airflow than the baseline or non-vortex mode.
However, the airflow (e.g., mass flow rate) discharged through the vents may be higher in the vortex venting mode than in the baseline or non-vortex mode. The use of discrete local vents positioned to accept the vortex discharge may also have similar heat transfer and airflow increases over a more evenly distributed vent of similar net cross-section (i.e., a short vent extending the entire lateral length of the back wall).
The venting system may be provided as a retrofit in an existing building or in a reengineering of an existing building configuration. Alternatively, the system may be implemented in a clean sheet design. Exemplary building spaces include tall elevator lobbies/atria of office buildings.
System properties may be optimized via a combination of experimentation and simulation (e.g., computational fluid dynamics). Further complexities of shape, parts, and the like may be added beyond those shown. An exemplary engineering/optimization process may initially dimension various components based upon estimated properties. This may be followed by experimental or simulation refinement. For example, in the basic structure of
One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, details of building layout, local climate, and building orientation may influence any particular implementation. Additionally, the degree to which the implementation involves a clean sheet design rather than a retrofit of an existing building may further influence any particular implementation. Accordingly, other embodiments are within the scope of the following claims.
The invention was made with U.S. Government support under contract 70NANB4H3024 awarded by the National Institute of Standards and Technology. The U.S. Government has certain rights in the invention.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US07/04389 | 2/21/2007 | WO | 00 | 8/21/2009 |