Patent Application
20110121087
There are a number of ways to heat and air condition spaces within buildings. In many office buildings heating and air conditioning is achieved through ducts in the ceilings of the buildings. However, because the cooling air is introduced from above, it forces some of the warmer air in the ceiling downward, resulting in cooling inefficiencies and a reduction in ventilation effectiveness. Ceiling-based systems also are often expensive to install, service, or modify, since all of the required ducting, and terminals, among other things, are located in the ceilings.
Alternatively, in many office buildings heating and air conditioning is achieved through ducts and plenums in the floors of the buildings. Typical floor terminals used with raised-floor systems in the industry are placed in an air passageway in the floor. Conditioned air is provided to the space above the floor via the terminals and is controlled by throttling mechanical dampers to adjust the airflow into the space. Such a throttling process produces inefficiencies in dispersing the conditioned air to the space. Often the conditioned air stays near the floor and does not disperse throughout the space, thereby creating large temperature variations from the floor to the ceiling. Further, such temperature variations decrease the effectiveness of a thermostat in holding a steady temperature within the space.
Embodiments of the invention are defined by the claims below, not this summary. A high-level overview of various aspects of the invention are provided here for that reason, to provide an overview of the disclosure, and to introduce a selection of concepts that are further described below in the detailed-description section below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in isolation to determine the scope of the claimed subject matter.
Accordingly, an under-floor trough with a heating element is provided that is mountable in an air passageway beneath a floor. The under-floor trough is used in conjunction with a raised-floor system. Conditioned air is provided to a subspace, or air passage between the raised-floor system and a sub-floor. The under-floor trough selectively controls the amount of air emitted to a room above the floor. The under-floor trough includes an air-delivery assembly, dampers, a diffuser, a support system, and a heating element.
The air-delivery assembly is mounted in an opening in a raised-floor system such that conditioned air from beneath the raised floor passes through the air-delivery assembly and into a room above the raised floor. The dampers are coupled to the air-delivery assembly and each preferably includes a vane coupled to a stepper motor. The stepper motor actuates the vane between an open and a closed position thereby controlling the flow of air through the damper. The diffuser is disposed over the air-delivery assembly to direct the flow of conditioned and/or heated air exiting the air-delivery assembly into the room.
The support system includes a bracket mounted to a vertical structure and engages a first flange depending outwardly from the air-delivery assembly. A second flange depending outwardly from the air-delivery assembly engages the raised-floor system thereby allowing the air-delivery assembly to hang via the first and second flanges under normal loads. Legs are disposed between the bottom of the air-delivery assembly and the sub-floor to support the air-delivery assembly under loading conditions. A heating element is disposed within the air-delivery assembly to provide heated air to the space above the raised-floor system when needed.
In another aspect, a method for providing conditioned air to a room from an under-floor trough in a raised-floor system is provided. A raised-floor system and an under-floor trough are provided, the under-floor trough having an air-delivery assembly, dampers, and a diffuser. An indication is received from a thermostat that a temperature set point is exceeded and a time modulated duty cycle is generated. Conditioned air is provided beneath the raised-floor system and the dampers are actuated to control the flow of conditioned air from beneath the raised floor to the space above the floor based on the time modulated duty cycle.
Illustrative embodiments of the invention are described in detail below with reference to the attached drawing figures, and wherein:
The subject matter of various embodiments of the invention is described with specificity herein to meet statutory requirements. The description itself, however, is not intended to necessarily limit the scope of claims. Rather, the claimed subject matter might be embodied in other ways to include different components or combinations of components similar to the ones described in this document, in conjunction with other present or future technologies.
Embodiments of the invention include an under-floor trough with a heating element and a method for providing conditioned air in a raised-floor system. In one embodiment, an under-floor trough with a heating element for positioning in a passageway in a raised-floor system is described. An air-delivery assembly including a pair of sidewalls, a back having a first outwardly depending flange, a bottom, a front having a second outwardly depending flange, and a baffle is provided. The baffle extends between the pair of sidewalls and is coupled to the back by brackets. Dampers are coupled to the front of the air-delivery assembly, each having a frame with a housing. The housing contains a motor and a vane coupled between the frame and the housing. The motor is coupled with the vane to actuate the vane between a first position and a second position to selectively vary the flow of air. A diffuser is removeably disposed over the air-delivery assembly to direct the flow of air exiting the air-delivery assembly. A support system provides legs coupled between the bottom of the air-delivery assembly and a sub-floor and a bracket fixedly attached to a vertical structure and engaging the first flange of the back of the air-delivery assembly. An electric or fluid heated heating element is disposed within the air-delivery assembly, between the baffle and the front of the air-delivery assembly.
In another embodiment, an under-floor trough with a heating element for positioning in a passageway in a raised-floor system is provided. An air-delivery assembly including a first and second sidewall, a back having a first outwardly depending flange, a bottom, a front having a second outwardly depending flange, a baffle, first and second partitions, and a control unit are described. The first and second partitions are coupled between the front and the back, and the control unit is removeably disposed therebetween. The baffle extends between a first sidewall and a first partition and is coupled to the back by brackets. Dampers are coupled to the front of the air-delivery assembly. Each of the dampers has a frame with a housing. The housing contains a motor. A vane is coupled between the frame and the housing and the motor is coupled with the vane to actuate the vane between a first position and a second position to selectively vary the flow of air. A diffuser is removeably disposed over the air-delivery assembly to direct the flow of air exiting the air-delivery assembly. A support system having legs coupled between the bottom of the air-delivery assembly and a sub-floor, and a bracket fixedly attached to a vertical structure and engaging the first flange of the back of the air-delivery assembly are also provided. An electric and/or fluid heated heating element is disposed between the baffle and the front of the air-delivery assembly and is in communication with the control unit.
In another aspect, a method for providing conditioned air to a room from an under-floor trough in a raised-floor system is described. A raised-floor system is provided. The raised-floor system provides conditioned air within a space between a sub-floor and a raised floor. An under-floor trough having an air-delivery assembly, dampers, and a diffuser is also provided. The air-delivery assembly is supported by a first outwardly depending flange engaging a bracket mounted to a wall, a second outwardly depending flange engaging the raised floor, and legs coupled between the air-delivery assembly and the sub-floor. The dampers are coupled to the air-delivery assembly. Each of the dampers has a motor coupled with a vane to actuate the vane between a first position restricting the flow of conditioned air and a second position allowing conditioned air to flow into the room, and wherein the diffuser is removeably disposed over the air-delivery assembly to direct the flow of air exiting the air-delivery assembly into the room. An indication is received from a thermostat that a temperature set point is exceeded. A time modulated duty cycle for supplying conditioned air to a room to maintain a temperature set point is generated. Conditioned air is supplied to the room according to the duty cycle by actuating all of the vanes of the dampers substantially simultaneously from the first position to the second position to allow conditioned air to flow into the room, or from the second position to the first position to restrict the flow of conditioned air to the room.
Referring now initially to
The air-delivery assembly 102 includes a back 106, a bottom 108, a front 110, and a pair of opposed sidewalls 112 coupled between the back 106 and the front 110. The back 106, bottom 108, and front 110 are preferably integrally formed from a single piece of sheet metal and the pair of sidewalls 112 preferably have an inwardly depending flange 113 along two sides to allow the sidewalls 112 to be joined to the back 106 and front 110 by fasteners (not shown), as illustrated in
The control unit 116 may include any necessary components for controlling a heating element, as described in greater detail below. The control unit 116 is a drop-in unit such that it may be installed and/or removed from above the under-floor trough 100 by manually lowering the control unit 116 into position between the pair of partitions 114. One or more receptacles may be located within the location between the pair of partitions such that when the control unit 116 is lowered into position an equal number of connectors on the control unit 116 engage the receptacles. The receptacles thereby connect the control unit 116 to any desired components and power sources. Alternatively, the control unit 116 might be lowered into position and a number of connections made manually by attaching wires or connectors thereto.
The control unit 116 is in communication with a thermostat or a second control unit that indicates to the control unit 116 when operation of the associated heating element is desired. Alternatively, the control unit might have an integrated thermostat thereby allowing the control unit to independently determine heating needs. In another embodiment, the control unit 116 also controls the dampers 104 as described below. The control unit 116 receives commands from a thermostat or other control device indicating a desired actuation of the dampers 104.
A baffle 118 is preferably disposed between one of the partitions 114 and one of the sidewalls 112 and coupled to the back 106 by a plurality of brackets 120. With additional reference to
With reference now to
The housing 138 contains a cover (not shown) and houses a motor (not shown), having an output shaft (not shown), that protrudes from an aperture 154 located in the housing 138. The motor, while not shown, is a preferably stepper motor that uses magnetic attraction to move the vane 130 between an open or second position (
The motor, along with the damper 104, are disclosed in U.S. patent application Ser. No. 10/606,085 (issued as U.S. Pat. No. 7,241,217) which is herein incorporated by reference. As discussed therein, a control system for the damper 104 receives input signals from a thermostat or other sensor in the room. Based on the signals received, the control system provides control signals to the motor which operates the damper 104. The control system may provide an “open” signal or a “close” signal to the motor. When an open signal is provided, the motor is activated to rotate the vane 130 of the damper 104 to the second, or open position, and the damper 104 remains in that position until a close signal is provided, wherein, the motor rotates the vane 130 of the damper 104 to the first, or closed position.
The control of the damper 104 involves assigning the damper 104 a time modulated duty cycle having a fairly short duration, normally under two minutes and often amounting only to seconds. During each duty cycle, the damper 104 is maintained open (or “on”) for a time period that is dependent upon a set point temperature and the actual temperature in the room or space. During the remainder of each duty cycle, the damper 104 is maintained closed (or “off”). The duration of each “open” or “on” time period is adjusted in order to maintain the set point temperature.
The vane 130 is connected with the housing 138 and the frame 126 by the pair of hubs 128. The vane 130 is a generally rectangular piece of metal that extends between the sidewall 134 of the frame 126 and the housing 138. The details of the hubs 128 are described but not shown. The hubs 128 each contain a channel (not shown) that receives a portion of the vane 130. The hubs 128 also each contain an aperture (not shown). The aperture of one hub 128 receives the output shaft of the motor while the aperture of the other hub 128 receives a rod (not shown) that is rotatably coupled with the aperture 146 of the sidewall 134. This allows the vane 130 to be rotated relative to the frame 126 between the first and second positions by activation of the motor.
As depicted in
With continued reference primarily to
The support system further includes the bracket 180 mounted to a wall 188 or other vertical structure. The bracket 180 comprises one or more sections of angle steel (steel bar having two parallel, adjacent, flat portions perpendicular to one another) and is fixedly attached to the wall 188 by fasteners. The bracket 180 may comprise any suitable form produced from any suitable material. In an embodiment a glue, caulk, or other sealant is disposed between the bracket 180 and the wall 188 to provide a greater seal against the flow of air between the bracket 180 and the wall 188. The bracket 180 engages the first flange 107 of the back 106 of the air-delivery assembly 102 by providing a rigid surface on which the first flange 107 rests. The engagement of the bracket 180 and the first flange 107 may also provide a seal against the flow of air between the bracket 180 and the air-delivery assembly 102. An additional component of the support system is the raised floor system 174. The raised floor system 174 also provides a rigid upper surface 173 upon which the second flange 111 of the front 110 of the air-delivery assembly 102 rests.
As such, the under-floor trough 100 is supported primarily by the first flange 107 resting atop the bracket 180 and the second flange 111 resting atop the raised-floor system 174 under normal loads (e.g. the weight of the under-floor trough 100). Under loading conditions, such as where a person or object exerts a downward force on the diffuser 164, the support provided by the bracket 180, the flanges 107 and 111, and the raised-floor system 174 may not be sufficient to retain the under-floor trough 100 within its position in the raised-floor system 174. Thus, the legs 178 provide additional support to aid in counteracting such loading conditions. In another embodiment, the legs 178 provide the primary support for the under-floor trough 100 under normal loads and under loading conditions.
The heated-fluid heating element 202 includes a pipe 208 and a plurality of vanes 210 coupled around the pipe 208. The pipe 204 enters and exits the air-delivery assembly 204 through apertures 212 (only one of which is visible in
With reference now to
Initially, the vanes 130 of the dampers 104 are in a first or closed position, as depicted by the shadowed lines of
By actuating the vanes 130 to the open position, depicted in
For example, under-floor trough systems of the prior art employ a method of mechanically throttling a damper to control the flow rate of a generally continuous input of conditioned air into a room. As such, the flow rate of conditioned air is kept at a level much less than 100% of the available flow and is varied between 0% and 100% by throttling the damper. Thus, as the conditioned air exits such trough systems, it stays near the floor and fills the room from the floor up due to the low buoyancy of cold air and because there is not a sufficient flow rate to eject the conditioned air into the upper elevations of the room. Issues with such a system include large temperature variations from the floor, which is very cool, to the ceiling, which is much warmer. Additionally, in such circumstances the cold air does not easily reach the elevation of a controlling thermostat. Therefore, the thermostat continues to call for additional cooling even though the lower elevations of the room may be well below a temperature set point. This may lead to great inefficiencies in the cooling of the room as well as occupants thereof being uncomfortable.
By employing the time modulated duty cycle and actuating the dampers 104 between fully open and fully closed as described above, a much more efficient cooling process may be achieved. Further, the high flow rate of conditioned air through the under-floor trough 100 causes the conditioned air flow to higher elevations of the room and mix more evenly throughout the room. Additionally, by employing the time modulated duty cycle to pulse the flow of conditioned air to the room, a generally equal volume of conditioned air as might be used in a mechanically throttled system of the prior art described above is used. Thus, a generally equal amount of conditioned air is used to provide a much more uniformly cooled room. As such, over time, embodiments of the invention may become increasingly more efficient over mechanically throttled systems of the prior art, because occupants and thermostats of rooms cooled by the prior art systems may make inefficient adjustments to compensate for the uneven dispersion of conditioned air within the room, among other reasons.
Referring again to
Additionally, the positioning of the under-floor trough 100 along a wall 188 is advantageous in that the wall 188 is often an exterior wall which may have one or more windows. As such, the wall 188 is generally cooler than the interior of the room and thus the air near the wall 188 is cooler. The cool air near the wall 188 readily sinks, or flows downward into the under-floor trough 100 due to its reduced buoyancy as compared to the warmer air within the room. The additional air flow imparted by the sinking cooler air along the wall 188 may further increase the circulation of air throughout the room as the air cycles through the under-floor trough 100, into the room and back toward the wall 188.
In an embodiment, the control unit 116 directs a heating cycle in which the electric heating element 122 is pulsed. Such a pulsed heating cycle may provide increased benefits to efficiency and circulation among other benefits.
In another embodiment, an under-floor trough 200 includes a fluid-heated heating element 202. The fluid-heated heating element is heated by a fluid, such as for example water provide via a boiler system. The heating of the element is controlled by a thermostat or other suitable control unit. Further, the heating and airflow created therefrom are similar to that described above with respect to the under-floor trough 100 having an electric heating element 122.
Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the scope of the claims below. Embodiments of the inventive technology have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to readers of this disclosure after and because of reading it. Alternative means of implementing the aforementioned can be completed without departing from the scope of the claims below. Certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims.
