This invention relates in general to a multi-zone integral face bypass coil system, and deals more particularly with a multi-zone integral face bypass coil system that provides greater flexibility with two or more heating zones, and greater protection against damaging environmental condition, than known systems.
Integral face bypass (IFB) coil systems are known in the art and typically employ a single input and output header for feeding a predetermined amount of hot water or steam through a series of heating coils. The coils are themselves disposed within selectively actuating damper devices, which open and close by a given degree in order to permit a varying amount of inlet air to pass directly over the coils.
While these known integral face bypass coil systems are successful to a degree, it is desirable to increase the efficiency of such systems. That is, known integral face bypass coil systems, commonly referred to as VAV (Variable Air Volume) systems, are increasingly being asked to provide for heating requirements over a wide span of temperature ranges and circulation volumes. If the swing in the desired volume of air being processed by known integral face bypass coil systems is too great, it is possible that the pressure within the coils can drop to levels that may lead to the freezing of condensate in the coils, and thus related structural damage or failure.
Similarly, known integral face bypass coil systems must be manufactured to handle wide swings in the volume of treated air, therefore the components in these systems are large in size, and may in fact be ‘over-built’ when the systems are utilized in small-volume applications. Moreover, the damper-drive assemblies of known integral face bypass coil systems are complex and that take up a fair amount of room, as well as being less precise than possible due to the large number of linkages utilized in such assemblies.
Still yet another aspect of known integral face bypass coil systems that may be improved lies in the nature, complexity and expense of the valves utilized therein. That is, owing to the use of variable speed blowers and variable air volume control systems, many known integral face bypass coil systems utilize modulating valves that maintain desired pressure, but often fall short of desired steam volume.
With the forgoing problems and concerns in mind, it is the general object of the present invention to provide a multi-zone integral face bypass coil systems which overcomes the above-described drawbacks while maximizing effectiveness, flexibility and environmental hardiness.
It is an object of the present invention to provide a multi-zone, vertical integral face bypass (VIFB) apparatus.
It is another object of the present invention to provide a multi-zone, VIFB apparatus having two or more heating manifolds.
It is another object of the present invention to provide a multi-zone, VIFB apparatus that provides protection against damaging environmental conditions.
It is another object of the present invention to provide a multi-zone, VIFB apparatus that may be fashioned from smaller gauge materials, and smaller diameter piping.
It is another object of the present invention to provide a multi-zone, VIFB apparatus that is more energy efficient.
It is another object of the present invention to provide a multi-zone, VIFB apparatus that provides more precise temperature conditioning than known single-manifold systems.
It is another object of the present invention to provide a multi-zone, VIFB apparatus that utilizes direct-driven dampers.
In accordance, therefore, with one embodiment of the present invention, an air handling system for selectively and incrementally heating a flow of inlet air entering the air handling system through an inlet opening includes a first heating coil assembly in fluid communication with a first inlet manifold header and a first outlet manifold header, and a second heating coil assembly in fluid communication with a second inlet manifold header and a second outlet manifold header. The first heating coil assembly is oriented forward of the second heating coil assembly such that the first heating coil assembly is disposed closer to the inlet opening than the second heating coil assembly.
These and other objectives of the present invention, and their preferred embodiments, shall become clear by consideration of the specification, claims and drawings taken as a whole.
In those circumstances where the inlet air need not be warmed to the extent necessary as in
While the known VIFB apparatus 100 has been shown and described in connection with
That is, as discussed previously, known VIFB apparatuses are typically fashioned to have relatively large inlet and outlet manifold headers, 102 and 104 respectively, and heating coils 106, so as to accommodate large temperature rises in the inlet air, or large increases in the volume of inlet air to be conditioned. Such systems, however, typically suffer when the increase in air flow temperature is desired to be much smaller; that is, when the ΔT (the instructed rise in the temperature of the outside inlet air) is small, or when the volume or air to be conditioned is small.
For example, in those cases where the ΔT is small, it may not be sufficient for the clam-shell dampers 108 to close fully, as shown in
As will be appreciated, when the flow rate within the heating coils 106 is reduced, the pressure within the heating coils 106 is correspondingly reduced and the VIFB apparatus 100 therefore becomes susceptible to environmentally-induced damage, such as freezing. Moreover, it is also practically difficult to precisely regulate the incremental reduction of flow-rate and pressure within the heating coils 106 so as to provide the type of fine temperature control oftentimes needed in modern day buildings.
Complicating the fine control of known VIFB apparatuses even further is the complex set of linkages 110 that control the selective positioning of the clam-shell dampers 108. Not only are known damper linkages 110 relatively cumbersome and space-consuming, their numerous integral components each contribute a measured amount of mechanical tolerances, or ‘play’, thus making the overall control of the clam-shell dampers 108 less definable and accurate.
Thus, known VIFB apparatuses as shown in
The present invention addresses the problems of known VIFB apparatuses, and provides an architecture that not only accommodates the conditioning of inlet air flow over wide temperature and volumetric ranges, but does so without endangering the integral heating coils, via freezing or the like. Moreover, the present invention removes the complex linkages of known VIFB apparatuses with a direct-connection control for the clam-shell dampers, as discussed hereinafter.
As is also shown in
It is therefore an important aspect of the present invention that the first heating/conditioning assembly 209 not only accomplishes the conditioning of inlet air, but also acts as an environmental barrier to the second heating/conditioning assembly 213. Thus, as will be described in more detail below, the first heating/conditioning assembly 209 acts to prevent freezing of the second heating/conditioning assembly 213.
In a preferred method of operation, and specifically in those applications where the VIFB apparatus 200 must operate over a wide temperature and/or volumetric range, the first heating/conditioning assembly 209 is operated at a substantial, to substantially maximum, capacity, thus insuring that the first heating/conditioning assembly 209 enjoys a high pressure, high flow-rate environment of heated water, steam or the like at all times. The selective operation of the clam-shell dampers 214 will thereby permit the first heating/conditioning assembly 209 to effectuate accurate, precise and efficient control over, approximately and at least, the first half of the total temperature range of the VIFB apparatus 200.
The second heating/conditioning assembly 213 need only then be operated in those high ΔT conditions when the temperature differential between the inlet air and the instructed air flow temperature is approximately outside of the first half of the total temperature range of the VIFB apparatus 200, and therefore outside of the ability of the first heating/conditioning assembly 209 to adequately address.
In such high ΔT situations, the second heating/conditioning assembly 213 can be selectively actuated by the operation of valves and the like, the workings of which are commonly known to those in the art. When so actuated, the second heating/conditioning assembly 213 supplements the ability of the clam-shell dampers 214 and the first heating/conditioning assembly 209, to accomplish a system-instructed rise in the temperature of the inlet air anywhere within the total temperature range of the VIFB apparatus 200.
The present invention thus provides a multi-zone approach to the conditioning of inlet air, in which two separate heating/conditioning systems are selectively utilized to accomplish system-instructed temperatures rises in inlet air over a wider range of temperatures, and with a level of precision and efficiency not heretofore known in the art.
In contrast to known systems, the multi-zone VIFB apparatus 200 of the present invention provides a second, and separate, manifold header assembly 208/204 that feeds a separate, matching second set of heating coils 212. By providing the second set of heating coils 212, and by selectively activating them on a case by case basis in dependence upon the volume of conditioned air required by the control system, or in times of high ΔT requirements, the present invention can ease the burden currently placed upon the single header/heating coil arrangement of known systems.
In low ΔT conditions when the temperature differential between the inlet air and the instructed air flow temperature is approximately within the first half of the total desired temperature range of the VIFB apparatus 200, the second heating/conditioning assembly 213 is operated at a minimum, to substantially negligible, capacity. That is, the second heating/conditioning assembly 213 can be largely inactive in those situations where the first heating/conditioning assembly 209 (by acting in combination with the clam-shell dampers 214) is capable of fully accomplishing a system-instructed rise in the temperature of the inlet air.
It should of course be understood that although operation of the VIFB apparatus 200 has been chiefly discussed in connection with accomplishing the instructed rise in the temperature of the inlet air stream, the applicability of the present invention is not so limited. Indeed, the selective actuation of the second heating/conditioning assembly 213 may be alternatively controlled by the volumetric demands placed upon the VIFB apparatus 200. In this regard, when the volume of inlet air to be conditioned is within the capacity of the first heating/conditioning assembly 209, taking into account the instructed temperature rise in that volume of inlet air, the second heating/conditioning assembly 213 remains inactive. However, should the volume, or combination of volume and instructed temperature rise, in the inlet air stream be beyond the design specifications of the first heating/ conditioning assembly 209, the control system of the VIFB apparatus 200 may selectively actuate the second heating/conditioning assembly 213 to compensate for the same.
It is therefore yet another important aspect of the present invention that the second heating/conditioning assembly 213 may be only selectively utilized, thus making the overall VIFB apparatus 200 more efficient over its entire temperature and volumetric range by only coming ‘on-line’ when needed.
Another important aspect of the present invention lies in the increased efficiency in the VIFB apparatus 200, as compared to known single-manifold header systems. By utilizing two separate, yet complimentary, stand-alone heating/conditioning assemblies, the present invention is capable of finer and more precise control over the entire temperature and volumetric range of the VIFB apparatus 200.
The present invention also envisions disposing the second set of heating coils 212 behind the first set, thereby insulating the second set from environmental damage. That is, by orienting the second set of heating coils 212 in a sheltered position behind the first set of heating coils 206, and by continually pressurizing the first set of coils at or near their maximum, the heated water or steam coursing through the first set of heating coils 206 provides a friendly environmental zone within which the second set of heating coils 212 are enveloped and therefore protected from freezing temperatures, even when the second set of heating coils 212 is run at low pressures, or completely shut off.
Indeed, a preferred embodiment of the present invention can be seen in
It is another important aspect of the present invention that as the first set of heating coils 206 are continually operated at a high, if not maximum, capacity, the first set of heating coils 206 are themselves protected against freezing.
Still yet another important aspect of the present invention is that the proposed multi-zone integral face bypass coil system is capable of utilizing simple slow-acting steam valves, instead of the complex seat valves typically utilized with known single-coil designs.
Moreover, by providing two separate manifold headers/heating coil assemblies, the size and gauge of the constituent components of the headers and the coils may be correspondingly reduced for each assembly. That is, smaller diameter coils and smaller manifold header boxes may be employed, thus reducing material cost, labor and assembly time. Another advantageous effect of reducing the size of the components is that the overall weight and dimensions of the system as a whole can be substantially reduced.
The present invention also replaces the complex linkages utilized in known systems to drive the clam-shell dampers, with a direct-drive damper system 300. As shown in
In contrast to the known complex and indirect damper linkage 110 shown in
It is therefore another important aspect of the present invention that the proposed direct-drive damper system is considerably smaller and may be arranged within the outer dimensions of the VIFB apparatus 200 (instead of being mounted so as to extend outwards from the VIFB apparatus, as shown in
Moreover, as the controlling arms 302 of the direct-drive damper system 300 are rigidly fixed to both a drive hub 306 and to the control rods 304, precise movement of the control rods 204 may be effectively accomplished without any of the mechanical ‘play’ inherent in the known, in-directly driven damper drives.
Although the present invention has been described such that the first heating/conditioning assembly 209 is designed to address approximately half of the total temperature or volumetric range of the VIFB device, with the second heating/conditioning assembly 213 being selectively called upon to address the remaining approximate half of the total temperature or volumetric range, the present invention is not limited in this regard. Indeed, the VIFB apparatus 200 of the present invention may be selectively designed so that the first and second stand-alone heating/conditioning assemblies address a greater or lesser portion of the total system range in temperature or volume, in dependence upon the specific design characteristics needed for a given application.
While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all equivalent embodiments.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/548,120, filed on Feb. 26, 2004, and herein incorporated by reference in its entirety.
Number | Date | Country | |
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60548120 | Feb 2004 | US |