AIR HANDLING UNIT WITH A HEATING MODULE

Description

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims the benefit of U.S. Provisional Ser. No. 63/636,094 filed on Apr. 18, 2024, U.S. Provisional Ser. No. 63/636,093 filed on Apr. 18, 2024, and U.S. Provisional Ser. No. 63/636,095 filed on Apr. 18, 2024, which are incorporated by reference herein in its entirety.

BACKGROUND

The embodiments described herein relate to air handling units for heating, ventilation, and air conditioning (HVAC) systems.

SUMMARY

Disclosed herein is an air handling unit for use with an air conditioning system. The air handling unit comprises a housing duct through which air is moved from an inlet to an outlet, a blower disposed inside the housing duct, configured for moving air within the housing duct, and a heater module coaxially disposed inside the housing duct along a direction of flow of air, wherein the heater module comprises a frame formed by a mesh of rods, configured to be removably disposed inside the housing duct, and a heating element removably attached to and supported on the frame such that the heating element remains coaxially disposed inside the housing duct, wherein the heating element has a shape selected based on an airflow pattern of air flowing through the heater module such that the air flows through the heating element of the heater module.

In one or more embodiments, the heater module is disposed downstream of the blower.

In one or more embodiments, the blower is a mixed airflow blower.

In one or more embodiments, the heating element is supported on the frame using one or more thermally and electrically insulative devices to electrically and thermally isolate the frame from the heating element.

In one or more embodiments, the heating element is supported on the frame using one or more ceramic holders to electrically and thermally isolate the frame from the heating element.

In one or more embodiments, the frame is made of an electrically and thermally insulative material.

In one or more embodiments, the frame comprises a set of rods arranged parallelly, orthogonally, and/or diagonally to each other along a plane to form the mesh of rods defining the shape of the frame, wherein the formed mesh has an outer profile based on an inner profile of the housing duct.

In one or more embodiments, the frame comprises a first set of rods arranged parallelly to each other along a plane, a second set of rods arranged orthogonally to the first set of rods, and a third set of rods arranged diagonally with respect to the first and second set of rods to form the mesh of rods defining the shape of the frame.

In one or more embodiments, the parallelly arranged set of rods or the first set of rods extend between opposite inner walls of the housing duct.

In one or more embodiments, the frame comprises a first support plate connecting a first end of each of the first set of rods, wherein the first support plate is configured to be removably attached to an inner wall of the housing duct and a second end of each of the first set of rods is configured to be removably attached to another wall, opposite to the first support plate, of the housing duct.

In one or more embodiments, the frame further comprises a first support plate connecting a first end of each of the first set of rods and a second support plate connecting a second end of each of the first set of rods, wherein the first support plate and the second support plate are configured to be removably attached to opposite inner walls of the housing duct.

In one or more embodiments, the first and/or second set of rods remains in contact with the heating element via one or more ceramic holders.

In one or more embodiments, electrical terminals of the heating element extend through the first support plate and/or the support second plate, wherein an insulator is configured between the electrical terminals and the first support plate and/or the second support plate.

In one or more embodiments, the heating element comprises a substantially circular ring-shaped profile.

In one or more embodiments, the ring-shaped heating element has an inner radius and a thickness based on the airflow pattern of air flowing through the heater module, such that the air flows across the heating element.

In one or more embodiments, heating capacity of the heating element associated with the heater module is variable.

In one or more embodiments, the heating element has a linear shape comprising one or more passes and turns.

In one or more embodiments, the heating element is formed by an angular spiral wound electrical wire of a predefined resistance.

In one or more embodiments, the heater module further comprises a controller operatively connected to the heater module and configured to adjust the heating capacity of the corresponding heating element based on an air leaving temperature being maintained downstream of the heater module.

In one or more embodiments, the controller is positioned on a first or second support plate.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, features, and techniques of the disclosure will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the subject disclosure of this disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the subject disclosure and, together with the description, serve to explain the principles of the subject disclosure.

In the drawings, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

FIG. 1A illustrates an exemplary schematic representation of an air handling unit with a heating module, in accordance with one or more embodiments of the subject disclosure.

FIG. 1B illustrates an exemplary schematic representation of an air handling unit with multiple heating modules, in accordance with one or more embodiments of the subject disclosure.

FIG. 1C illustrates an exemplary schematic representation of a temperature control and safety system implemented in a heater assembly of an air handling unit, in accordance with one or more embodiments of the subject disclosure.

FIGS. 2A and 2B illustrate exemplary representations of an embodiment of the heating modules of FIGS. 1A and 1B, in accordance with one or more embodiments of the subject disclosure.

FIGS. 3A and 3B illustrate exemplary representations of another embodiment of the heating modules of FIGS. 1A and 1B, in accordance with one or more embodiments of the subject disclosure.

FIG. 4 illustrates an exemplary schematic representation of a method for enabling temperature control and safety in a heater assembly of an air handling unit, in accordance with one or more embodiments of the subject disclosure.

DETAILED DESCRIPTION

The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject disclosure as defined by the appended claims.

Various terms are used herein. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the subject disclosure, the components of this disclosure described herein may be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower,” “first,” “second” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components.

Air handling unit (AHU) associated with heating, ventilation, and air conditioning (HVAC) systems may be integrated with mixed airflow blowers to achieve a combination of airflow patterns. However, optimization and efficiency issues may arise when the AHU is paired with a supplemental heating module involving conventional heating elements. Traditionally, rod-style heating elements, often configured in 4 or 6 pass designs may be employed in the heater assembly/module. These elements may be designed to heat air directly as it passes over them, relying on a straightforward, linear airflow for effective heat transfer.

The effectiveness of the AHU is predicated on the ability of the heating element to uniformly transfer heat to the air moving over its surface. The mixed airflow blower has introduced a complex, non-linear airflow pattern that may not be well-matched with the simple, linear design of traditional rod-style heating elements. This mismatch may lead to several problems that may undermine the performance and efficiency of the AHU or the heater assembly/module. Primarily, the incompatibility between the heating elements and the airflow patterns may result in inefficient heat transfer. This inefficiency may manifest as uneven heating, with certain areas receiving less heat than intended, and the creation of hot spots within the HVAC unit and the associated ductwork. These hot spots may not only be a sign of energy waste but may also pose a risk to the reliability and lifespan of the system by potentially damaging the heating elements and other components through excessive thermal stress. In addition, the heating capacity of the supplemental heating module associated with the existing AHU is also limited, resulting in a limited operational range for air heating capabilities.

There is, therefore, a need to overcome the above-mentioned limitations and drawbacks, by providing an improved heating solution in air handling units which aligns with the airflow characteristics of the air flowing through the AHU to ensure efficient and evenly distributed heating of the air, and also provide a wide range of heating capacity.

Further, electric heating systems are widely used in residential, commercial, and industrial settings due to their efficiency, reliability, and ease of installation. In such applications, the supplemental electric heater assembly is employed in AHU along with a heat exchanger to control the temperature of air supplied by the AHU.

The heater assembly converts electric energy into heat, which is then used for heating the air flowing through the AHU. The core component of the heater assembly is the electric heat element, which generates heat when an electrical current flows through it. Safety is an important concern in the design and operation of heater assemblies. Over-temperature conditions may occur in the heater assembly or AHU due to various reasons. These conditions may not only reduce the efficiency of the heater assembly and the AHU but may also pose significant safety risks, including the potential for fire hazards and damage to the nearby components. Besides, these conditions may also lead to an uncontrolled temperature rise or drop in the air leaving the AHU.

Existing safety mechanism employed in heater assemblies to prevent over-temperature conditions is a temperature-based bimetal switch. This switch may be designed to interrupt the electrical current to the heating element when the air temperature leaving the heater exceeds a pre-set limit. However, the application of temperature-based bimetal switches may present several challenges.

One of the primary limitations of such solutions is the need for customizing the size and application of each electric heating element. Given the diverse range of electric heater assembly designs and the specific requirements of different applications, each bimetal switch must be individually set for a unique temperature limit. This not only complicates the manufacturing process but also increases the cost and complexity of managing different bimetal switch configurations. Furthermore, the reliance on a fixed temperature limit may not account for the dynamic conditions under which the heater assembly operates.

Therefore, there is also a need for an improved and reliable temperature control and safety solution for heater assembly associated with the AHU which provides a more adaptable and reliable solution for preventing over-temperature conditions, ensuring the safety, efficiency, and longevity of the heater assembly and the AHU.

Referring to FIGS. 1A, 1B, and 1C, an air handling unit (AHU) 100 for use with an air conditioning system (not shown in figures) is disclosed. The AHU 100 may include a housing duct 102 fluidically coupling an inlet 102-1 and an outlet 102-2. Air may be moved through the housing duct 102 from the inlet 102-1 to the outlet 102-2 along a direction 112 of the flow of air.

In one or more embodiments, the AHU 100 may further include a heat exchanger 104. The heat exchanger 104 may be disposed within the housing duct 102 along the direction 112 of flow of the air, such that the air flowing through the housing duct 102 further flows through the heat exchanger 104. The heat exchanger 104 may be configured to facilitate the transfer of heat to and from the air moving through the housing duct 102. In one or more embodiments, the heat exchanger 104 may be configured to cool the air moving through the housing duct 102. In one or more other embodiments, the heat exchanger 104 may be configured to heat the air moving through the housing duct 102. In one or more embodiments, the heat exchanger 104 may include a primary heat exchanger 104 and other heat transfer devices (not shown). In one or more embodiments, the heat exchanger 104 may be a ducted fan coil unit (FCU) (as shown in the embodiment of FIG. 1A). In one or more embodiments (not shown), the heat exchanger 104 may further be coupled with a humidifier to facilitate the air passing through the heat exchanger 104 to include (predefined) levels of moisture.

In one or more embodiments, the AHU 100 may further include a supplemental heating module/assembly 106 (also referred to as a heating device or heating module 106). In one or more embodiments, the supplemental heating module 106 may be disposed within the housing duct 102, along the direction 112 of flow of the air, such that the air flowing through the housing duct 102 flows through the heating module 106 and the heat exchanger 104, as shown in FIGS. 1A and 1B. The supplemental heating module 106 may be configured to heat the air passing through the housing duct 102. In one or more embodiments, the supplemental heating module 106 and the heat exchanger 104 may together be configured to heat the air and regulate the heated air temperature, respectively, that is flowing through the housing duct 102.

The AHU 100 may further include a blower 108 or a fan disposed inside the housing duct 102. In one or more embodiments, the blower 108 may be a mixed airflow blower 108 but is not limited to the like. The blower 108 may be configured to move the air through the housing duct 102, from the inlet 102-1 to the outlet 102-2. In one or more embodiments, the blower 108 may include an impeller operable by a motor (not shown). The motor may be a direct-drive motor. The motor may be operable with continuous speed control. The motor may be communicably coupled to the HVAC controls of an air conditioning unit. As the blower 108 rotates, the blower 108 may pull in air through the inlet 102-1 and blow the air through the blower 108 and towards the outlet 102-2 through the housing duct 102. The blower 108 may have an axis of rotation that is in-line with the direction 112 of the flow of the air through the housing duct 102.

In one or more embodiments, the blower 108 may be positioned downstream relative to the heat exchanger 104. However, in one or more other embodiments, the blower 108 may be positioned upstream relative to the heat exchanger 104. In the illustrated embodiment of FIG. 1A, the blower 108 is positioned downstream relative to the heat exchanger 104. Further, in the illustrated embodiment of FIG. 1A, the blower 108 is positioned upstream relative to the supplemental heating module 106. However, in one or more other embodiments, the blower 108 may be positioned downstream relative to the supplemental heating module 106 without any limitation. Furthermore, in one or more embodiments, the heat exchanger 104 may be substantially V-shaped relative to the direction 112 of the flow of the air through the housing duct 102. However, in one or more other embodiments, the heat exchanger 104 may have any other configurations as well without any limitations and all such embodiments are well within the scope of the subject disclosure.

In one or more embodiments, the heating module 106 may be coaxially disposed within the housing duct 102 (along axis A-A′), along the direction of flow of the air, such that the air downstream of the blower 108 flows through the heating module 106, as shown in FIG. 1A. In one or more embodiments, the heater assembly 106 may include a plurality of heating modules 106-1 to 106-N (collectively referred to as heating modules/assembly 106). Each of the heating modules 106-1 to 106-N may be coaxially stacked over each other along the direction 112 of the airflow within the housing duct 102, as shown in FIG. 1B.

Referring to FIGS. 1C to 3B, the AHU 100 may include one or more thermistors 114 (collectively referred to as thermistors 114, herein) configured at positions around or adjacent to a heating element 204 or one or more heating elements (designated as 204 in FIGS. 2A to 3B) associated with the heating module(s)/assembly 106. The thermistors 114 may be configured to monitor the temperature of the heating element 204 and/or the temperature of the air leaving or flowing through the heating element 204 or heating module(s) 106. In one or more embodiments, the thermistors 114 may be positioned adjacent to the heating element 204 along a plane of the heating element 204. However, in some embodiments, the thermistors 114 may be positioned adjacent to the heating element 204 along a plane downstream and at a predefined distance from the plane of the heating element 204.

Referring to FIGS. 2A to 3B, in one or more embodiments, the heating modules/assembly 106 may include a frame 202 formed by a mesh of rods 202-1 to 202-3, where the heating element 204 is supported on the frame 202. In such embodiments, the thermistors 112 may be positioned on at least one of the rods 202-1 to 202-3 of the frame 202 such that the thermistors 112 remain around and adjacent to the heating element 204.

The frame 202 may be configured to be removably disposed inside the housing duct 102. The heating modules 106 may further include a heating element 204, removably attached to and supported on the frame 202 such that the heating element 204 is/remains coaxially disposed inside the housing duct 102 upon coaxially positioning the heating modules 106 within the housing duct 102. The shape of the heating element 204 may be selected based on an airflow pattern of the air (downstream of the blower 108) flowing through the heating modules 106 such that the air flows through the heating element 204 of the heating modules 106, which may improve thermal interaction between the flowing air and the heating element 204. Further, in one or more embodiments, the heating element 204 may have variable (or adjustable) heating capacity. In other embodiments, the heating element 204 may have a fixed heating capacity.

In one or more embodiments, as shown in FIGS. 2A and 2B, the heating element 204 of the heating modules 106 may have a substantially circular ring-shaped profile. Further, the ring-shaped heating element 204 may have an inner radius and a thickness selected based on the airflow pattern of the air flowing through the respective heating modules 106, such that the air (downstream of the blower 108) flows through the heating element 204. In such embodiments, the thermistors 114 may be positioned on the rods 202-1 to 202-3 of the frame 202 such that the thermistors 114 remain positioned circumferentially around and adjacent to an outer curved circumference of the ring-shaped heating element 204 and/or in a central hollow region of the ring-shaped heating element 204.

In one or more embodiments, the heating element 204 may be formed by an angular spiral wound electrical wire of a predefined resistance based on the heating capacity. Further, in one or more embodiments, multiple such spiral wound wires may be coaxially disposed along the same plane with a gap therebetween to form the ring-shaped heating element 204.

In one or more embodiments, the radius and/or thickness of the heating element 204 of each of the heating modules 106-1 to 106-N in the heater assembly 106 may be different. Further, in some embodiments, the radius and/or thickness of the heating element 204 of at least two heating modules among the plurality of heating modules 106-1 to 106-N may be different. However, in other embodiments, the radius and/or thickness of the heating element 204 associated with each of the heating modules 106-1 to 106-N may be the same, while the heating capacity of the heating modules 106-1 to 106-N may be different.

It is to be appreciated that the radius (whether same or different) of the heating element 204 of the heating modules 106-1 to 106-N is selected based on the airflow pattern of the air (downstream of the blower 108) flowing through the heating module 106-1 to 106-N, as a result, the major portion of the air downstream of the blower 108 may flow through the heating element 204 of the heating modules 106-1 to 106-N, which may improve thermal interaction between the flowing air and the heating element 204.

In one or more embodiments, the radius and/or thickness of the heating element 204 of each of the heating modules 106-1 to 106-N may decrease towards downstream side of the heater assembly 106. For instance, the radius and/or thickness of the heating element 204 of the heating module 106-1 may be more than that of the heating module 106-2, and the radius and/or thickness of the heating element 204 associated with the heating module 106-2 may be more than that of the heating module 106-3. However, in other embodiments, the radius and/or thickness of the heating element 204 associated with each of the heating modules 106-1 to 106-N may increase towards the downstream side of the heater assembly 106.

In one or more embodiments, as shown in FIGS. 3A and 3B, the heating element 204 of the heating module 106 may have a linear shape having one or more passes or turns. For instance, the heating element 204 may have a linear shape comprising six passes as shown in FIG. 3A or four passes as shown in FIG. 3B. The heating element 204 may be formed by an angular spiral wound electrical wire of a (predefined) resistance having a linear shape, which may be turned or folded to define the passes and turns. Further, in one or more embodiments, an overall area of such heating element 204 may have a circular profile or other profile based on the airflow pattern of the air flowing through the respective heating module 106, such that the air (downstream of the blower 108) flows through the heating element 204. In one or more embodiments, the thermistors 114 may be positioned on the rods of the frame 202 such that the thermistors 114 remains positioned around and adjacent to an outer periphery of the corresponding heating element 204.

Referring back to 1B to 3B, in one or more embodiments, the heating capacity of the heating element 204 of each of the heating modules 106-1 to 106-N may be different. Further, in some embodiments, the heating capacity of the heating element 204 associated with at least two heating modules among the plurality of heating modules 106-1 to 106-N may be different. However, in other embodiments, the heating capacity of the heating element 204 associated with each of the heating modules 106-1 to 106-N may be the same/equal.

In one or more embodiments, the heating capacity of the heating element 204 of each of the heating modules 106-1 to 106-N may decrease towards downstream side of the heater assembly 106. For instance, the heating capacity of the heating element 204 associated with the heating modules 106-1 may be more than that of the heating module 106-2, and the heating capacity of the heating element 204 associated with the heating module 106-2 may be more than that of the heating module 106-3. However, in other embodiments, the heating capacity of the heating element 204 associated with each of the heating modules may increase towards the downstream side of the heater assembly 106. 3

For instance, in a non-limiting example, a first heating module 106-1 of the heater assembly 106 may have a heating capacity of 10 KW, a second heating module 106-2 of the heater assembly 106 may have a heating capacity of 3 KW, and a third heating module 106-N of the heater assembly 106 may have a heating capacity of 1 KW. Accordingly, the overall heater assembly 106 may provide a wide range of heating capacity ranging from 1 KW to 14 KW. Further, based on the heating modules being switched, the overall heater assembly 106 may provide heating capacities of 1 KW, 3 KW, 4 KW, 5 KW, 8 KW, 10 KW, 12 KW, 15 KW, 18 KW, 20 KW, and 25 KW.

In another non-limiting embodiment, a first heating module 106-1 of the heater assembly 106 may have a variable heating capacity ranging from 5 to 10 KW, a second heating module of the heater assembly 106 may have a heating capacity of 3 KW, and a third heating module of the heater assembly 106 may have a heating capacity of 1 KW. Accordingly, the overall heater assembly 106 may provide a wide range of heating capacity ranging from 1 KW to 14 KW. However, based on the heating modules being switched, the overall heater assembly 106 may provide heating capacities of 1 KW, 3 KW, 4 KW, 5 KW, 8 KW, 10 KW, 12 KW, 15 KW, 18 KW, 20 KW, and 25 KW.

Thus, the use of different heating modules 106-1 to 106-N having the same or different heating capacity may allow the heater assembly 106 to provide a wide range of heating capacity. Further, the heating modules 106-1 to 106-N may be accordingly switched and their heating capacity may also be adjusted to maintain a ‘first’ temperature of the corresponding heating elements 204 at a ‘second’ temperature (or temperature threshold) and/or maintain a ‘third’ temperature of the air leaving/flowing through the heating assembly 106 at a ‘fourth’ temperature (or another temperature threshold), which may be further supplied out of the AHU 100A via the outlet 102-2 of the housing duct 102.

Further, referring to FIGS. 2A to 3B, in one or more embodiments, the heating element 204 may be supported on the frame 202 using one or more thermally and electrically insulative devices to electrically and thermally isolate the frame 202 from the heating element 204. In one or more embodiments, the heating element 204 may be supported on the frame 202 using one or more ceramic holders 206 (also referred to as ceramic guides 206, herein) to electrically and thermally isolate the frame 202 from the heating element 204. Further, in one or more embodiments, the frame 202 may also be made of an electrically and thermally insulative material.

In one or more embodiments, the frame 202 may include a set of rods 202-1 to 202-3 arranged parallelly, orthogonally, and/or diagonally to each other along a plane to form the mesh of rods defining the shape of the frame 202. The rods 202-1 to 202-3 may be arranged to define the frame 202 based on an inner profile of the housing duct 102 such that an outer profile of the frame 202 allows the frame 202 or the heating modules 106 to be coaxially fitted within the housing duct 102, without any hindrance.

In one or more embodiments, as shown in FIGS. 2A and 2B, the frame 202 may include a first set of rods 202-1 arranged parallelly to each other along a plane, a second set of rods 202-2 arranged orthogonally to the first set of rods 202-1, and a third set of rods 202-3 arranged diagonally with respect to the first and second set of rods 202-1, 202-2 to form the mesh of rods defining the shape of the frame 202. Further, these rods 202-1 to 202-3 may remain in contact via the ceramic holders or ceramic guides 206. Accordingly, the formed mesh or the frame 202 may have an outer profile based on the inner profile of the housing duct 102, allowing the frame 202 or the heating modules 106 to be coaxially fitted within the housing duct 102 without any hindrance. However, in other embodiments, the rods 202-1 to 202-3 may be arranged in other fashions as well without any limitations to define the frame 202, as long as the frame 202 allows installation of the heating element 204 thereon and further allows installation of the frame 202 or heating modules 106 coaxially within the duct 102 without any hindrance. Further, the parallelly arranged set of rods (or the first set of rods 202-1) may extend between opposite inner walls of the housing duct 102 to support and help secure the frame 202 or heating modules 106 within the housing duct 102.

In one or more embodiments, the frame 202 may include one or more support plates 208-1, 208-2 connected to at least one end of the set of rods 202-1 to 202-3. The support plate(s) may 208-1, 208-2 be configured to be removably attached to an inner wall of the housing duct to secure the heating module 106 within the housing duct. Further, the thermistors 112 may be positioned on at least one of the support plates among the support plates 208-1, 208-2, such that the thermistors 112 remain adjacent to the heating element 204 for monitoring the temperature of the corresponding heating element 204 and the air leaving or flowing through the heating element 204.

In addition, in one or more embodiments, the frame 202 may include a first support plate 208-1 connecting the first end of each of the first set of rods 202-1 and a second support plate 208-2 connecting the second end of each of the first set of rods 202-1. The first support plate 208-1 and the second support plate 208-2 may be configured to be removably attached to opposite inner walls of the housing duct 102, allowing the heating modules 106 to be secured within the housing duct 102. However, in one or more embodiments, the frame 202 may only include the first support plate 208-1 connecting the first end of each of the first set of rods 202-1. In such embodiments, the first support plate 208-1 may be configured to be removably attached to an inner wall of the housing duct 102 and the second end of each of the first set of rods 202-1 may be configured to be removably attached to another wall, opposite to the first support plate 208-1, of the housing duct 102. Furthermore, in other embodiments, the frame 202 may include four support plates being connected in a substantially square or rectangular shape, with the rods 202-1 to 202-3 extending between opposite plates and the heating element 204 supported on the rods 202-1 to 202-3. In such embodiments, the support plates 208 may be configured to be removably attached to the inner walls of the housing duct 102.

In one or more embodiments, the AHU 100 may further include a packaged rooftop air management system that may be communicably coupled to the different components of the AHU 100, including, without limitations, the heat exchanger 104, the (supplemental) heating modules 106, the blower 108, and the motor.

Referring back to FIGS. 1A to 3B, the AHU 100 may include a controller 110 configured to control the operations of the different components of the AHU 100 (as depicted in FIGS. 1A and 1B) and control the heating modules 106. The controller 110 may include one or more processors coupled to a memory storing instructions executable by the processors, which may cause the controller to perform the designated operations.

In one or more embodiments, the controller 110 that may be in communication with different components of the AHU 100, including, without limitations, the thermistors 114, the heating module(s) 106, the blower 108, and the heat exchanger 104. The controller 110 may be configured to control the operations of the different components of the AHU 100. The controller 110 may include one or more processors 110-1 coupled to a memory 110-2 storing instructions executable by the processors 110-1, which may cause the controller 110 to perform the designated operations.

The controller 110 may be configured to monitor, using the thermistors 114, a ‘first’ temperature of the heating element 204 and/or a ‘third’ temperature of the air leaving or flowing through the heating element 204 associated with each of the heating module(s) 106. The controller 110 may accordingly adjust the heating capacity of the heating element(s) 204 based on the monitored/determined (i.e., the first and/or third temperatures), to maintain the first temperature of the heating element(s) 204 at a second temperature or a temperature threshold, and/or maintain the third temperature of the air flowing through or leaving/exiting the heating assembly 104 at a fourth temperature or another temperature threshold.

In one or more embodiments, when the first temperature of the heating element 204 of the heating module(s) 106 is detected to be below the second temperature, the controller 110 may be configured to reduce the heating capacity of the one or more heating element(s) 204 associated with the heater modules 106 upon detecting the third temperature of the air leaving/or flowing through the heater assembly 106 to exceed the fourth temperature. Further, in one or more embodiments, when the first temperature of the heating element 204 of the heating module(s) 106 is detected to be below the second temperature, the controller 114 may be configured to increase the heating capacity of the one or more heating element(s) 204 associated with the heater modules 106 upon detecting the third temperature of the air leaving or flowing through the heater assembly 106 to be below the fourth.

Furthermore, in one or more embodiments, the controller 110 may be configured to switch the one or more heating element(s) 204 off associated with the heater assembly/module(s) 106 upon detecting the first temperature of the corresponding heating element 204 to exceed the second temperature and/or upon detecting the temperature of the air leaving or flowing through the heater assembly/modules 106 to exceed the second temperature.

In addition, in some embodiments, the controller 110 may additionally control the switching and/or speed of the blower 108 of the AHU 100 to maintain the first temperature of the heating element 204 at the second temperature and/or the third temperature of the air leaving or flowing through the heater assembly 106 at the fourth temperature.

Accordingly, these operations may facilitate the AHU 100 to bring and maintain the third temperature of the air leaving or flowing through the heater assembly 106 at the fourth predefined temperature, while keeping the first temperature of the heating element 204 of the heating module 106(s) below the second (safe) temperature.

In one or more embodiments, a dedicated controller 110 may be associated with heater assembly 106, where the controller 110 may be removably secured on any of the heating modules 106 as shown in FIGS. 2A to 3B. In other embodiments, each of the heating modules 106 may include a separate controller 110, where each of the controller 110s may be in communication with each other and/or the AHU 100 via a wired or wireless network. Further, in some embodiments, the controller 110 may be a part of the HVAC controls of the AHU 100 as well.

In one or more embodiments, electrical terminals 204-1 of the heating elements 204 may extend through the first support plate 208-1 and/or the support second plate 208-2 to allow the electrical connection of the heating modules 106 to the controller 110 and a power source associated with the AHU 100A, 100B. In such embodiments, slots may be formed in any of the support plates 208 to allow extension of the terminals 204-1 therethrough. In addition, an insulator 210 may be configured between the electrical terminals 204-1 and the support plate(s) 208 to electrically and thermally isolate the electrical terminals 204-1 from the duct 102 as well as the frame 202. Further, in one or more embodiments, the controller 110 may be part of each the heating modules 106 where the controller 110 may be removably secured on any of the support plates 208 associated with the heating modules 106, thereby forming a modular/stackable heater assembly 106 as shown in FIG. 2B which can be stacked and/or easily removably configured within the housing duct 102 of any AHU 100. Further, in one or more embodiments, the controller 110 may be a part of the HVAC controls of the air conditioning system as well.

In one or more embodiments, the controller 110 and the thermistors 112 may form a temperature control and safety system.

Referring to FIG. 4, a method 400 for enabling temperature control and safety in a heater assembly or heating modules associated with an air handling unit is disclosed. The method 400 may involve the thermistors 114, the controller 114, and various other components associated with the system 100 and AHU 102 of FIGS. 1A, 1B, and/or 1C. In one or more embodiments, method 400 may include step 402 of monitoring/determining, using the one or more thermistors configured (at predefined positions) around a heating element of the heater assembly, a first temperature of the heating element. The method 400 may further include step 404 of adjusting the heating capacity of the heating element based on the first temperature, to maintain the first temperature at a second temperature/temperature threshold.

In one or more embodiments, the method 400 (such as at step 402) may also include determining a third temperature of air leaving/flowing through the heater assembly. In one or more embodiments, the method 400 (such as at step 404) may also include adjusting the heating capacity of the heating element based on the third temperature, to maintain the third temperature at a fourth temperature/another temperature threshold.

In one or more embodiments, method 400 may include step 406 of switching the heating element(s) off when the first temperature of the heating element(s) exceeds the second temperature and/or when the third temperature of the air leaving/flowing through the heater assembly exceeds the fourth temperature/another temperature threshold.

Further, in one or more embodiments, when the first temperature of the heating element falls below the second temperature, method 400 may include the steps of reducing the heating capacity of the heating element when the third temperature of the air leaving the heater assembly exceeds the fourth temperature. Furthermore, when the first temperature of the heating element falls below the second temperature, method 400 may include the steps of increasing the heating capacity of the heating element when the third temperature of the air leaving the heater assembly goes below the fourth temperature.

Furthermore, in one or more embodiments, method 400 may include the steps of controlling switching and/or adjusting the speed of the blower associated with the air handling unit to maintain the first temperature of the heating element at or below the second temperature and/or the third temperature the air leaving the heater assembly at or below the fourth temperature. Accordingly, these operations may facilitate bringing and maintaining the third temperature of the air leaving the heater assembly at the fourth temperature, while keeping the first temperature of the heating element of the heating module(s) below the second (safe) temperature.

Throughout the specification, the term first temperature and the third temperature refer to real-time/actual temperature of the heating elements or the air flowing through the heating elements at the time of measurement or determination by the thermistors 114. The value of the first and the third temperatures may change at each iteration of the method 400, and may be affected on performance/execution of the adjusting step 404. Further, the second temperature and the fourth temperature refer to threshold temperatures determined and/or set for the first and third temperatures, respectively.

Thus, the subject disclosure overcomes the limitations and drawbacks associated with existing bimetallic strip-based temperature control systems, by providing an improved and reliable temperature control and safety system and method that provides a more adaptable and reliable solution for preventing over-temperature conditions, ensuring the safety, efficiency, and longevity of the heater assembly and the AHU.

The subject disclosure also provides an improved heating solution in AHUs by providing the heating module comprising a heating element having a shape/design based on the airflow characteristics of the air flowing through the AHU. This improves the thermal interaction between the air and the heating element, thereby ensuring efficient and evenly distributed heating of the air downstream of the blower/fan. As a result, the use of different heating modules having the same or different heating capacities may allow the heater assembly to provide a wide range of heating capacities. This may help control the temperature of the corresponding heating elements and/or further control and vary the temperature of the air leaving the heating elements.

In addition, the heating modules have a modular, stackable, and/or shock-proof design that may allow technicians to easily stack and install the heating modules within or remove the heating modules from the housing duct associated with existing AHUs. Moreover, the shock-proof and thermally safe design allows the heating modules to safely operate within the AHU without affecting the other components of the AHU.

While the disclosure has been described with reference to exemplary 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 disclosure as defined by the appended claims. Modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed, but that the disclosure includes all embodiments falling within the scope of the disclosure as defined by the appended claims.

In interpreting the specification, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C. . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

Without excluding further possible embodiments, certain example embodiments are summarized in the following clauses:

• • Clause 1: An air handling unit for use with an air conditioning system, the air handling unit comprising:
    • a housing duct through which air is moved from an inlet to an outlet;
    • a blower disposed inside the housing duct, configured for moving air within the housing duct; and
    • a heater assembly comprising a plurality of heating modules coaxially stacked over each other along a direction of the airflow, the heater assembly coaxially disposed inside the housing duct along a direction of flow of the air, wherein each of the heating modules comprises a frame formed by a mesh of rods, the frame configured to be removably disposed inside the housing duct, and a heating element, removably attached to the frame, and wherein the heating element has a shape selected based on an airflow pattern of the air flowing through the respective heating module such that the air flows through the corresponding heating element.
  • Clause 2: The air handling unit of preceding clause, wherein the heating element associated with each of the heating modules is supported on the frame using one or more thermally and electrically insulative devices to electrically and thermally isolate the frame from the heating element.
  • Clause 3: The air handling unit of any of the preceding clauses, wherein the frame is made of an electrically and thermally insulative material.
  • Clause 4: The air handling unit of any one of the preceding clauses, wherein the heating element has a substantially circular ring-shaped profile, and wherein the ring-shaped heating element has an inner radius and a thickness based on the airflow pattern of the air flowing through the respective heating module.
  • Clause 5: The air handling unit of preceding clause 4, wherein the radius and/or thickness of the heating element associated with each of the heating modules is different.
  • Clause 6: The air handling unit of preceding clause 4, wherein the radius and/or thickness of the heating element associated with each of the heating modules decreases towards a downstream side of the heater assembly.
  • Clause 7: The air handling unit of preceding clause 4, wherein the radius and/or thickness of the heating element associated with at least two heating modules among the plurality of heating modules is different.
  • Clause 8: The air handling unit of preceding clause 4, wherein the radius and/or thickness of the heating element associated with each of the heating modules is same.
  • Clause 9: The air handling unit of any the preceding clauses, wherein the heating element has a linear shape comprising one or more passes and turns,
  • Clause 10: The air handling unit of the preceding clause 9, wherein an area of the linear shaped heater is circular or based on the airflow pattern of the air flowing through the respective heating module.
  • Clause 11: The air handling unit of any of the preceding clauses, wherein the heating capacity of the heating element associated with each of the heating modules is different.
  • Clause 12: The air handling unit of any of the preceding clauses, wherein the heating capacity of the heating element associated with at least two heating modules among the plurality of heating modules is different.
  • Clause 13: The air handling unit of the preceding clause 12, wherein the heating capacity of the heating element associated with each of the heating modules decreases towards a downstream side of the heater assembly.
  • Clause 14: The air handling unit of any of the preceding clauses, wherein the heating capacity of the heating element associated with each of the heating modules is same.
  • Clause 15: The air handling unit of any of the preceding clauses, wherein the heating capacity of the heating element associated with at least one of the heating modules of the heater assembly is variable.
  • Clause 16: The air handling unit of any of the preceding clauses, wherein the frame comprises at least one support plate connecting at least one end of each of a set of rods.
  • Clause 17: The air handling unit of preceding clause 16, wherein the at least one support plate is configured to be removably attached to an inner wall of the housing duct to secure the corresponding heating module within the housing duct.
  • Clause 18: The air handling unit of preceding clause 16, wherein electrical terminals of the heating element extend through the at least one plate and an insulator is configured between the electrical terminals and the corresponding support plate.

Further example embodiments are summarized in the following clauses:

• • Clause 1: A temperature control and safety system for an air handling unit configured with a supplemental heater assembly, the system comprising:
    • one or more thermistors configured around or adjacent to a heating element of the heater assembly; and
    • a controller operatively connected to the one or more thermistors, the heating element, and a blower of the air handling unit, wherein the controller comprises one or more processors coupled to a memory storing instructions executable by the processors, which causes the controller to:
      • determine, using the one or more thermistors, a first temperature of the heating element; and
      • adjust a heating capacity of the heating element based on the determined first temperature, to maintain temperature of the heating element at a second temperature.
  • Clause 2: The system of the preceding clause, wherein the controller is further configured to:
    • determine, using the one or more thermistors, a third temperature of air flowing through the heating element; and
    • adjust the heating capacity of the heating element based on the determined third temperature, to maintain the third temperature of the air flowing through the heating element at a fourth temperature.

Clause 3: The system of any of the preceding clauses, wherein the one or more thermistors are positioned adjacent to the heating element along a plane of the heating element.

Clause 4: The system of any of the preceding clauses, wherein the one or more thermistors are positioned adjacent to the heating element along a plane downstream at a distance from a plane of the heating element.

Clause 5: The system of any of the preceding clauses, wherein the heating element is associated with a heater module being coaxially disposed, upstream or downstream of the blower, in a housing duct associated with the air handling unit, and wherein the one or more thermistors are configured at the predefined positions in the heating module.

Clause 6: The system of any of the preceding clauses, wherein the one or more thermistors are positioned, adjacent to the heating element, on a frame supporting the heater module.

Clause 7: The system of the preceding clause 6, wherein the one or more thermistors are positioned on at least one of the rods among a set of rods that form the frame, the thermistors being configured adjacent to the heating element.

Clause 8: The system of the preceding clause 7, wherein the frame comprises one or more support plates connected to at least one end of the set of rods, the one or more support plates configured to be removably attached to an inner wall of the housing duct.

Clause 9: The system of any of the preceding clause, wherein the one or more thermistors are positioned on at least one of the support plates among the one or more support plates.

Clause 10: The system of any of the preceding clauses, wherein the one or more thermistors are positioned around an outer curved circumference of the heating element having a ring-shaped profile.

Clause 11: The system of any of the preceding clauses, wherein the one or more thermistors are positioned around an outer periphery of the heating element having a linear shape.

Clause 12: The system of the preceding clause 2, wherein the controller is configured to switch the heating element off upon detecting the first temperature of the heating element to exceed the second temperature and/or upon detecting the third temperature of the air leaving the heater assembly to exceed the fourth temperature.

Clause 13: The system of the preceding clause 2, wherein when the first temperature of the heating element is below the second temperature, the controller is configured to reduce the heating capacity of the heating element upon detecting the third temperature of the air flowing through the heater assembly exceeds the fourth temperature.

Clause 14: The system of the preceding clause 2, wherein when the first temperature of the heating element is below the second temperature, the controller is configured to increase the heating capacity of the heating element upon detecting the third temperature of the air leaving the heater assembly to be below the fourth temperature.

Clause 15: The system of the preceding clause 2, wherein the controller is configured to control switching and/or speed of the blower to maintain temperature of the heating element at the second temperature and/or temperature the air leaving the heater assembly at the fourth temperature.

Clause 16: A method for enabling temperature control and safety in an air handling unit configured with a supplemental heater assembly, the method comprising:

• • determining, using the one or more thermistors configured around a heating element of the supplemental heater assembly, a first temperature of the heating element; and
  • adjusting a heating capacity of the heating element based on the determined first temperature, to maintain the first temperature of the heating element at a second temperature.
  • Clause 17: The method of the preceding clause 16, wherein the method comprising the steps of:
  • monitoring, using the one or more thermistors, a third temperature of air flowing through the heating element; and
  • adjusting the heating capacity of the heating element based on the determined third temperature, to maintain the third temperature of the air flowing through the heating assembly at a fourth temperature.
  • Clause 18: The method of the preceding clause 17, wherein the method comprises the steps of switching the heating element off when the first temperature of the heating element exceeds the second temperature and/or when the third temperature of the air flowing through the heater assembly exceeds the fourth temperature.
  • Clause 19: The method of the preceding clause 17, wherein when the first temperature of the heating element is below the second temperature, the method comprises the steps of reducing the heating capacity of the heating element when the third temperature of the air leaving the heater assembly exceeds the fourth temperature.
  • Clause 19: The method of the preceding clause 17, wherein when the first temperature of the heating element is below the second temperature, the method comprises the steps of increasing the heating capacity of the heating element when the third temperature of the air leaving the heater assembly falls below the fourth temperature.
  • Clause 20: The method of the preceding clause 17, wherein the method comprises the steps of controlling switching and/or adjusting speed of a blower associated with the air handling unit to maintain the first temperature of the heating element at the second temperature and/or the third temperature the air leaving the heater assembly at the fourth temperature.