Patent Description:
HVACR systems are generally used to heat, cool, and/or ventilate an enclosed space (e.g., an interior space of a commercial building or a residential building, an interior space of a refrigerated transport unit, or the like). An AHU is part of a HVACR system that is used to regulate and circulate air. A ductwork ventilation system can be connected to the AHU and directs conditioned air from the AHU to the enclosed space and air from the conditioned space to the AHU. The AHU can include a housing, fan(s), and heat exchanger(s). The heat exchanger be a combustion heater that directs combustion gases through heat exchanger tubes to heat air flowing past the heat exchanger tubes as it flows through the AHU. The AHU can also include one or more components of a refrigerant circuit of the HVACR system used to cool the air (e.g., the condenser, the evaporator, and the like).

<CIT> describes a furnace including an enclosure having a vertical support column formed by a heat exchanger compartment panel and a blower compartment panel. The furnace includes a window assembly having venting openings hidden by a viewing window. The furnace also includes a rail to support a removable heat exchanger system. The furnace further includes a wire retaining fin assembly to retain a wire. There is also described a heat exchanger header design including features to retain a sealant.

<CIT> describes a furnace including a cabinet having a top plate and a blower located in the cabinet. A blower shelf is located in the cabinet and has a first side supportive of the blower and a second side including one or more canted slide rails. A heat exchanger is located in the cabinet between the blower and the top plate and is securable to the one or more canted slide rails. The one or more canted slide rails are configured to allow removal of the heat exchanger from the cabinet along the canted slide rails without removal of the top plate from the cabinet.

<CIT> describes a protective housing structure for a heating, ventilation, and air conditioning system comprising a first end and a second end with a centerline extending therebetween. The protecting housing structure includes a cover section that is located between the first end and second end. The cover section comprises a dome-shaped top panel that is rigidly attached to a first sidewall and a second sidewall.

<CIT> describes a heating and cooling unit. Methods of installing and using the heating and cooling unit are also described. The heating and cooling unit includes a base member, a tube chase, a convertible drain, a system for mounting a burner box in a sideways orientation to a vestibule panel, a system for removably attaching a control panel to a collector box and a compressor supply plug.

<CIT> describes a condensing furnace assembly and method including a primary heat exchanger having a first zone and a second zone, and a secondary heat exchanger having a first zone and a second zone. A manifold assembly includes a first set and a second set of burners. The primary and secondary heat exchanger assemblies may include a plurality of aligned tubes. The plurality of tubes include a first zone and a plurality of the tubes include a second zone. A first air device is in communication with the first zone portions of the primary and secondary heat exchanger and the first set of burners. A second air device is in communication with the second zone of the primary and secondary heat exchangers and the second set of burners.

The invention is defined in the attached independent claims to which reference should now be made. Further, optional features may be found in the sub-claims appended thereto.

A heating, ventilation, air conditioning, and refrigeration ("HVACR") system can be utilized to heat and/or cool a conditioned space. The HVACR system can utilize an air handling unit ("AHU") to regulate and circulate air. The air handling unit receives air (e.g., air from the conditioned space, ambient air, and the like) and discharges conditioned air (e.g., heated, cooled, dehumidified, filtered, and the like) that is supplied to the conditioned space.

In an embodiment, the AHU includes a housing containing a combustion section and a combustion heater that disposed within the housing. The housing includes a first side with an opening for the combustion section. The combustion section has a first side wall with a first channel and a second side wall with a second channel. The combustion heater includes an end plate, heat exchanger tubes, and a tube support. The heat exchanger tubes extend from the end plate and into the combustion section. The tube support is slidably disposed in the first channel and the second channel and supports the heat exchanger tubes within the combustion section. The tube support is configured to slidably move through the first channel and the second channel in a first direction that moves the combustion heater through the opening in the housing.

In an embodiment, the tube support is configured to slidably move in the first direction through and from the first channel and the second channel such that the combustion heater is entirely moved through the opening in the housing.

In an embodiment, the first channel and the second channel each have an open end. The tube support has a retaining member slidably disposed in the first channel and the second channel. The moving the retaining member in the first direction through the open ends of the first channel and the second channel is configured to separate the combustion heater from the housing.

In an embodiment, the first channel and the second channel are configured to not limit the movement of the tube support in the first direction.

In an embodiment, the tube support includes a retaining member, the retaining member having a first end disposed in the first channel and a second end disposed in the second channel.

In an embodiment, the tube support includes a vertical support and a plurality of contact arms. The vertical support extends from the retaining member and each of the contact arms extends from the vertical support. Each of the heat exchanger tubes rests on a respective one of the plurality of contact arms. In an embodiment, each of the contact arms extends between a vertically adjacent pair of the heat exchanger tubes.

In an embodiment, the tube support is configured to vertically support the heat exchanger tubes within the combustion section.

In an embodiment, the first channel and the second channel are configured to restrict vertical movement of the tube support while allowing the tube support to move in the first direction.

In an embodiment, the first channel and the second channel are formed by a pair of brackets provided on opposite walls of the combustion section.

In an embodiment, the AHU includes one or more support clips for the heat exchanger tubes. Each of the support clips is fitted around a vertically adjacent pair of the heat exchanger tubes.

In an embodiment, an AHU includes a housing containing a fan section and a fan assembly disposed in the combustion section. The housing includes a first side with a first opening for the combustion section, a top side with a second opening for the combustion section, and a pair of rails disposed in the combustion section. The fan assembly includes one or more fans and a pair of grooves slidably disposed on the rails of the housing. The fan assembly is configured to be both slidably removable from the AHU through the first opening and liftably removable from the AHU through the second opening.

In an embodiment, the fan assembly is configured to be slidable along the pair of rails in a first direction to move the fan assembly through the first opening. The fan assembly is also configured to be liftable from the pair of rails in a second direction to move the fan assembly through the second opening. In an embodiment, the second direction is an upward direction.

In an embodiment, the pair of grooves includes a first groove and a second groove. The first groove is disposed on a first side of the fan assembly. The second groove is disposed on a second side of the fan assembly opposite to its first side.

In an embodiment, the grooves face downward and the rails project upwards.

In an embodiment, the fan(s) in the fan assembly is a radial fan.

In an embodiment, the AHU also includes a heater disposed in the fan section, the fan(s) of the fan assembly configured to blow air towards the heater.

Both described and other features, aspects, and advantages of an air handling unit will be better understood with the following drawings:.

Like references in the drawings refer to like features.

<FIG> is a schematic diagram of an embodiment of a heating, ventilation, air conditioning, and refrigeration ("HVACR") system <NUM>. The HVACR system <NUM> is configured to condition (e.g., heat, cool, dehumidify, and the like) a conditioned space by supplying conditioned air to the conditioned space <NUM>. The HVACR system can include a ductwork ventilation system <NUM> and an air handling unit ("AHU") <NUM>. The AHU <NUM> is connected to the ductwork ventilation system <NUM> that is configured to distribute the conditioned air discharged from the AHU <NUM> to the conditioned space <NUM>. The ductwork ventilation system <NUM> can also return air from the conditioned space <NUM> back to the AHU <NUM>.

The air to be conditioned flows through the AHU <NUM> from an inlet 12A to the outlet 12B of the AHU <NUM>. The air is conditioned as it flows from the inlet 12A to the outlet 12B of the AHU such that conditioned air is discharged from the outlet 12B. In an embodiment, the AHU <NUM> is configured to be capable of cooling and heating the air as it flows through the AHU <NUM>. In a heating mode, the AHU <NUM> heats the air as it flows through the AHU <NUM>. In a cooling mode, the AHU <NUM> cools the air as it flows through the AHU <NUM>.

The HVACR system <NUM> can include a refrigerant circuit <NUM> to provide cooling. The refrigerant circuit <NUM> can include a compressor <NUM>, a condenser <NUM>, an expander <NUM>, and an evaporator <NUM>. In an embodiment, the heat transfer circuit <NUM> can be modified to include additional components, such as, for example, an economizer heat exchanger, one or more valve(s), sensor(s) (e.g., a flow sensor, a temperature sensor, and the like), a receiver tank, or the like. The components of the heat transfer circuit <NUM> are fluidly connected as shown by the dashed lines in <FIG>.

The refrigerant circuit <NUM> operates by known principles of refrigerant compression and expansion to provide cooling. Working fluid (e.g., a refrigerant, a refrigerant blend, or the like) is compressed by the compressor <NUM>, cooled in the condenser <NUM>, and then expanded in the expander <NUM>. The expansion causes the working fluid to cool. The cool working fluid then flows through the evaporator <NUM>. The air flowing through the AHU <NUM> from the inlet 12A to the outlet 12B flows through the evaporator <NUM> separately from the working fluid. The cooler working fluid absorbs heat from the passing air and cools the air. The evaporator <NUM> cooling the air passing by/through the evaporator <NUM>.

As the air flows through the AHU <NUM> from its inlet 12A to its outlet 12B, the air flows through an evaporator <NUM> and a combustion heater <NUM>. In a heating mode, the AHU <NUM> operates the combustion heater <NUM> to heat the passing air. In a cooling mode, the AHU <NUM> can operate the refrigerant circuit <NUM> for the evaporator <NUM> to cool the passing air. The AHU <NUM> also includes a fan <NUM> to generate air flow through the AHU <NUM> from its inlet 12A to its outlet 12B.

As shown in <FIG>, the AHU <NUM> can contain components of the refrigerant circuit <NUM> other than evaporator <NUM>. The AHU <NUM> can include a condenser section <NUM> that utilizes air to cool one or more components of the refrigerant circuit <NUM>. In an embodiment, the AHU <NUM> can be configured to operate in a heat pump mode in which the evaporator <NUM> instead operates as a condenser that heats the air as it flows past. For example, the AHU <NUM> can include one or more fan(s) <NUM> that blow ambient air through the condenser <NUM> of the refrigerant circuit <NUM> to cool the working fluid flowing through the condenser <NUM>. The compressor <NUM> can also be disposed in the condenser section <NUM>. In an embodiment, the other components of the refrigerant circuit <NUM> may be located external to the AHU <NUM> (e.g., in a different AHU, within a building, and the like). The AHU <NUM> may also include other components for conditioning the air. The AHU <NUM> may include, for example but not limited to, an air filter <NUM>, dehumidifier, humidifier, and the like.

<FIG> is a front perspective view of an embodiment of an air handling unit ("AHU") <NUM> used in an HVACR system. In an embodiment, the AHU <NUM> can be the AHU <NUM> in the HVACR <NUM> shown in <FIG>. A ductwork ventilation system (e.g., the ductwork ventilation system <NUM> in <FIG>) can be connected to the AHU <NUM> that distributes conditioned air to a conditioned space (e.g., the conditioned space <NUM> in <FIG>) and then returns the air to the AHU <NUM> for conditioning. The AHU <NUM> includes a return inlet section <NUM>, a fan section <NUM>, and a condensing section <NUM>. The AHU <NUM> includes an inlet 108A and an outlet 108B (obscured in <FIG>; shown in <FIG>) for the air returning from and being provided to a conditioned space (e.g., the conditioned space <NUM> in <FIG>). The inlet 108A and outlet 108B can be located in the bottom of the AHU <NUM> (e.g., the bottom of the housing <NUM>). The sections <NUM>, <NUM>, <NUM> each have a depth that extends in a first direction D<NUM> and a height that extends in a second direction D<NUM>. For example, the second direction D<NUM> is perpendicular to the first direction D<NUM>. The sections of the AHU <NUM> are discussed in more detail below.

The AHU <NUM> includes a housing <NUM> with a plurality of sides. As shown in <FIG>, the AHU includes a first side <NUM>, a second side <NUM>, a third side <NUM> (obscured in <FIG>), a fourth side <NUM> (obscured in <FIG>), and a fifth side <NUM>. In <FIG>: the first side <NUM> is the front side, the second side <NUM> is the left side, the third side <NUM> is the right side, the fourth side <NUM> is the rear side, and the fifth side <NUM> is the top side of the AHU <NUM>. The sides of the housing <NUM> have panels (e.g., panel <NUM> of the front side <NUM>, panel <NUM> of the top side <NUM>, and the like). In an embodiment, one or more panels can be provided on each side. The panels can be opened to access the interior and one or more interior components of the AHU <NUM>.

The air enters the AHU <NUM> through the inlet 108A and is then discharged as conditioned air from the AHU <NUM> from the outlet 108B. The return inlet section <NUM> includes the inlet 108A. The fan section <NUM> includes the air outlet 108B. The air flows through the inlet 108A into the return inlet section <NUM>, from the inlet section <NUM> to the fan section <NUM>, through the fan section <NUM> to the outlet 108B, and is then discharged from the AHU <NUM> through the outlet 108B. The air is conditioned as it flows through the AHU <NUM> from the inlet 108A to the outlet 108B. For example, the air is conditioned within the return inlet section <NUM> and the fan section <NUM>.

In a heating mode, combustion gases are used to heat the air as it flows through the fan section <NUM>. In such a configuration, the fan section <NUM> can also be referred to as a combustion section. In an embodiment, the return inlet section <NUM> includes a cooling heat exchanger <NUM> of the HVACR system (e.g., the evaporator <NUM> in <FIG>). In a cooling mode, air flows through the cooling heat exchanger <NUM> as it flows through the return inlet section <NUM> and is cooled by a colder fluid (e.g., expanded refrigerant, chiller water, and the like) separately flowing through the cooling heat exchanger <NUM>. The return inlet section <NUM> may also be referred to as a cooling section. The condenser section <NUM> can contain a condenser of the refrigerant circuit of the HVACR system (e.g., condenser <NUM> in <FIG>). The condenser section <NUM> circulates air past the condenser to cool the working fluid as it flows through the condenser. In an embodiment, the HVACR system may utilize a condensing section <NUM> that is provided in separate second AHU (not shown). For example, the AHU <NUM> in such an embodiment would include the return inlet section <NUM> and the fan section <NUM> without the condensing section <NUM>.

<FIG> is partial front perspective view of the front side <NUM> of the AHU <NUM>. A panel <NUM> of the front side <NUM> is opened and removed in <FIG>. The panel <NUM> covers an opening <NUM> in the housing <NUM> for the fan a combustion heater <NUM> that extends into the fan section <NUM> of the AHU <NUM>. In a heating mode, the combustion heater <NUM> heats the air as it flows through the fan section <NUM>.

The combustion heater <NUM> includes an end plate <NUM>, igniters <NUM>, a plurality of heat exchanger tubes <NUM> (obscured in <FIG>; e.g., shown in <FIG>), and a fan <NUM>. The igniters <NUM> and fan <NUM> are provided on the end plate <NUM>. The heat exchanger tubes <NUM> are disposed in the airflow path through the fan section <NUM>. The igniters <NUM> ignite an air and fuel mixture flowing into the heat exchanger tubes <NUM>. The air and fuel mixture can be ignited before entering the heat exchanger tubes <NUM> or as the mixture flows into the heat exchanger tubes <NUM>. As the hot combustion gas flows through the heat exchanger tubes <NUM>, the air flowing through the fan section <NUM> absorbs heat from the hot combustion gas through the walls of the heat exchanger tubes <NUM>. The air is heated as it flows through the fan section <NUM> and past the heat exchanger tubes <NUM>. The fan <NUM> directs the air and fuel mixture and/or its resulting combustion gas to flow through the heat exchanger tubes <NUM>. For example, as shown in <FIG>, the fan <NUM> can provide suction to the outlets of the heat exchanger tubes <NUM> to generate flow through the heat exchanger tubes <NUM>. In another embodiment, the fan <NUM> may be upstream of the ignitors <NUM> and configured to blow the air and gas mixture to the ignitors <NUM>. The fan <NUM> can be configured to blow the cooled combustion gases out of the AHU <NUM>.

The combustion heater <NUM> is configured to be slidably removable from the AHU <NUM>. The combustion heater <NUM> is removed from the AHU <NUM> by moving through the opening <NUM> in the housing <NUM> in a direction D<NUM>. For example, the combustion heater <NUM> may be removed by being pulled through the opening <NUM> in the direction D<NUM>. The slidable removal of the combustion heater <NUM> is described in more detail below.

The removal of the combustion heater <NUM> includes fluidly and electrically decoupling the combustion heater <NUM> from the rest of the AHU <NUM>. For example, fluidly decoupling the combustion heater <NUM> can include decoupling the combustion heater <NUM> from the piping of the AHU <NUM> that supplies the air and fuel, separately or as a mixture, to the combustion heater <NUM>. Fluidly decoupling the combustion heater <NUM> can also include decoupling the exhaust outlet of the combustion heater <NUM> (e.g., the outlet vent of the fan <NUM>) from the housing <NUM>. Electrically decoupling the combustion exchanger unit <NUM> from the AHU <NUM> can include disconnecting one or more electrical wires for the combustion heater <NUM> (e.g., power supply wire(s), sensor signal wire(s), and the like).

In an embodiment, one or more retaining structures, such as fasteners (e.g., screws, bolts, clamps, and the like), flexible tabs, and the like, may be provided to secure the end plate <NUM> to the housing <NUM> so as to prevent minor movement and/or accidental movement of the combustion heater <NUM>. In such an embodiment, the removal of the combustion heater <NUM> can include removing such fasteners (e.g., flexing the flexible tab(s), unscrewing the screw(s) and/or bolt(s), removing clamp(s), and the like) to allow the movement and removal of the combustion heater <NUM>.

<FIG> shows a partial rear view of the interior of the AHU <NUM>. In particular, <FIG> illustrates the combustion heater <NUM> disposed in the fan section <NUM>. The arrows F<NUM> illustrate the flow of air through the fan section <NUM> past the heat exchanger tubes <NUM> and out through the outlet 108B. The heat exchanger tubes <NUM> generally extend in a direction perpendicular to the flow of air through the fan section <NUM>. For example, the heat exchanger tubes <NUM> extend from the end plate <NUM> of the combustion heater <NUM> in the direction D<NUM> that extends from the front to the back of the AHU <NUM>, while the air flows in a direction D<NUM> that extends from the top to the bottom of the AHU <NUM>.

Fan section <NUM> includes a pair of opposing side walls <NUM>, <NUM>. The side walls separate the fan section <NUM> from the other sections <NUM>, <NUM> of the AHU <NUM>. As shown in <FIG>, the side walls <NUM>, <NUM> are internal walls of the housing <NUM> of the AHU <NUM>. The first side wall <NUM> is an internal wall between the fan section <NUM> and the return inlet section <NUM>. The second side wall <NUM> is between the fan section <NUM> and the condenser section <NUM>. The side walls <NUM>, <NUM> can help direct the air across the heat exchanger tubes <NUM> and towards the outlet 108B in the bottom of the fan section <NUM>. The heat exchanger tubes <NUM> disposed between the side walls <NUM>, <NUM>. The side walls <NUM>, <NUM> can extend from the front of the AHU <NUM> to the rear of the AHU <NUM> (e.g., from the front side <NUM> to the rear side <NUM>) and from the bottom of the AHU <NUM> to the top of the AHU (e.g., from the bottom of the AHU to the top side <NUM>). The fan section <NUM> is formed by the front side <NUM>, the rear side <NUM>, and the top side <NUM> of the housing <NUM> and the side walls <NUM>, <NUM>.

As shown in <FIG>, the side walls <NUM>, <NUM> each have a channel 144A, 144B. The first side wall <NUM> includes a first channel 144A and the second side wall <NUM> includes a second channel 144B. The channels 144A, 144B disposed opposite to each other in the fan section <NUM>. For example, the first channel 144A has a longitudinal opening that faces the second side wall <NUM>, and second channel 144A has a longitudinal opening that faces the first side wall <NUM>. In combination, the two channels 144A, 144B form a slot across the fan section <NUM>. As shown in <FIG>, the channels 144A, 144B face each other across the combustion section. Each of the channels 144A, 144B extends along its respective side wall <NUM>, <NUM> and away from the front side <NUM> of the housing <NUM> (e.g., in the direction D<NUM> in <FIG>).

As shown in <FIG>, the channels 144A, 144B can be provided using a pair of brackets 146A, 146B. A first bracket 146A is affixed to the first side wall <NUM>, and a second bracket 146B is affixed to the second side wall <NUM>. For example, the first bracket 146A is affixed to the surface of the first wall <NUM> and the second bracket 146B is affixed to the surface of the second wall <NUM>. The first and second brackets 146A, 146B can respectively form the first and second channels 144A, 144B.

The combustion heater <NUM> includes a slidable tube support <NUM> that supports the heat exchanger tubes <NUM> within the interior space of the fan section <NUM>. The slidable tube support <NUM> is configured to be slidable along in the depth direction D<NUM> of the fan section <NUM> for moving the combustion heater <NUM> through the opening <NUM> in the housing <NUM> (shown in <FIG>). The tube support <NUM> is slidable/movable relative to the housing <NUM>. For example, this allows a technician (manually or machine assisted) to pull on the combustion heater <NUM> in the direction D<NUM> to slide the entire combustion heater <NUM> through the opening <NUM> in the housing <NUM>. In an embodiment, the opening <NUM> in the housing <NUM> is enlarged to allow removal of the combustion heater <NUM> by removing additional panels of the front side <NUM> of the housing <NUM>. The slidable tube support <NUM> can be used to partial remove the combustion heater <NUM> from the housing <NUM> (e.g., sliding the combustion heater <NUM> only partway through the opening <NUM>) or to completely remove the combustion heater <NUM> from the AHU <NUM> and the housing <NUM>. For example, the partial removal may be used by a technician to allow for easier repair of the combustion heater <NUM>, while the full removal can be used for larger repairs and/or for replacement of the combustion heater <NUM>.

The slidable tube support <NUM> includes a retaining member <NUM> that is slotted into the channels 144A, 144B. The retaining member <NUM> is slidably disposed in the channels 144A, 144B. The retaining member <NUM> extends from the first channel 144A to the second channel 144B. When the combustion heater <NUM> is installed in the AHU <NUM>, the retaining member <NUM> extends between the first side wall <NUM> the second side wall <NUM>. The retaining member <NUM> has a first end <NUM> and an opposite second end <NUM>. The first end <NUM> is disposed in the first channel 144A and the second end <NUM> is disposed in the second channel 144B. As the retaining member <NUM> is vertically trapped in the channels 144A, 144B, movement of the retaining member <NUM> in the vertical direction (e.g., in direction D<NUM>, in the opposite direction of the direction D<NUM>) is prevented/restricted while being free to move along the length of the channels 144A, 144B (e.g., into or out of the drawing in <FIG>, in direction D<NUM> in <FIG>, in direction D<NUM> in <FIG>). The channels 144A, 144b configured to limit vertical movement of the tube support <NUM> while not limiting the movement along the first direction D<NUM>.

The retaining member <NUM> is rotatable within the channels 144A, 144B. The combustion heater <NUM> is configured to pivot on the retaining member <NUM>. The retaining member <NUM> acts as the rotational axis for the pivoting of the combustion heater <NUM>. For example, the combustion heater <NUM> can be swung forwards towards the front side <NUM> (e.g., in direction D<NUM>) to pivot the combustion heater <NUM> and angle the combustion heater <NUM> at an incline towards the front side <NUM> (e.g., angled upwards in the direction D<NUM>). For example, the combustion heater can be swung backwards towards the rear side <NUM> (e.g., in direction D<NUM>) to pivot the combustion heater <NUM> and angle the combustion heater <NUM> to decline towards the front side <NUM> (e.g., angled downwards in the direction D<NUM>). The channels 144A, 144B and are configured to allow sliding of the retaining member <NUM> through the length of the channels 144A, 144B while restricting/preventing vertical movement. The retaining member <NUM> is configured to only be removable from the channels 144A, 144B sliding through the open ends of the channels 144A, 144B. The channels 144A, 144B are configured so that the retaining member <NUM> cannot be vertically removed from the channels 144A, 144B (e.g., prevents upward and downward pushing from removing of the retaining member <NUM> from the channels 144A, 144B). As shown in <FIG>, the combustion heater <NUM> can also include a plurality of adjacent tube support clips <NUM>. The support clips <NUM> are discussed in more detail below.

<FIG> is a partial vertical cross-sectional view of the combustion heater <NUM> as indicated in <FIG>, according to an embodiment. For example, <FIG> illustrates the interaction between the slidable tube support <NUM> and the heat exchanger tubes <NUM>. The retaining member <NUM> is fastened to one or more of the heat exchanger tubes <NUM> to prevent the retaining member <NUM> from moving relative to the heat exchanger tubes <NUM>. As shown in <FIG>, the retaining member <NUM> can be fastened around a group of the heat exchanger tubes <NUM>. The retaining member <NUM> can include a pair of brackets <NUM> that are fastened together with fasteners <NUM> (e.g., screws, bolts, clamps, and the like). One bracket <NUM> disposed above the group of heat exchanger tubes <NUM> and the second bracket <NUM> disposed below the group of heat exchanger tubes <NUM>. The heat exchanger tubes <NUM> being pinched between the fastened together pair of brackets <NUM>. The group of heat exchanger tubes <NUM> held between the pair of brackets <NUM>. It should be appreciated that the slidable tube support <NUM> can be prevented from sliding along the heat exchange tubes <NUM> in a different manner. For example, the slidable tube support <NUM> may be affixed to the heat exchange tubes <NUM> via welding, fasteners, or the like, or the heat exchanger tubes <NUM> may have exterior projections that prevent the tube support <NUM> from sliding along the outsides of the heat exchanger tubes <NUM>.

The slidable tube support <NUM> also includes a vertical support <NUM> and a plurality of contact arms <NUM>. As shown in <FIG>, the vertical support <NUM> extends from the retaining member <NUM>, and the contact arms <NUM> each extend outward from the vertical support <NUM>. For example, the contact arms <NUM> branch off from the vertical support <NUM>. The contact arms <NUM> are connected to the retaining member <NUM> by the vertical support <NUM>. For example, the vertical support <NUM> is directly connected to the retaining member <NUM>, and the contact arms <NUM> are each directly connected to the vertical support <NUM>.

The vertical support <NUM> extends along a column of the heat exchanger tubes <NUM>. As shown in <FIG>, the vertical support <NUM> can extend between two adjacent columns of the heat exchanger tubes <NUM>. In an embodiment, the vertical support <NUM> extend along an outside column of heat exchanger tubes <NUM>.

The heat exchanger tubes <NUM> rest on the contact arms <NUM>. Each heat exchanger tube <NUM> can rest on a respective contact arm <NUM>. In an embodiment, the contact arms <NUM> help to hold the heat exchanger tubes <NUM>. For example, the bottom surface of a heat exchanger tube <NUM> rests on the upper surface of its respective contact arm <NUM>. The contact arms <NUM> are prevented from vertically moving by the retaining member <NUM> being disposed/slotted in the channels 144A, 144B. The contact arms <NUM> vertically remain in place and provide a support surface for resting the heat exchanger tubes <NUM>. Each contact arm <NUM> prevents/limits the downward movement of its respective heat exchanger tube <NUM>.

In an embodiment, one or more of the exchanger tubes <NUM> may be contacted by just a single contact arm <NUM>. For example, the heat exchanger tubes <NUM> in the rightmost column of heat exchanger tubes <NUM> in <FIG> are each in contact with multiple contact arms <NUM>. In an embodiment, one or more of the heat exchanger tubes <NUM> may be contacted by multiple contact arms <NUM>. The heat exchanger tube <NUM> can rest on a first contact arm <NUM> as discussed above. A second contact arm <NUM> can contact the top of the heat exchanger tube <NUM> and be configured to prevent upward movement of the heat exchanger tube <NUM>. For example, the second contact arm <NUM> can also provide support to the upper adjacent heat exchanger tube <NUM>. The upper adjacent heat exchanger tube <NUM> rests on the upper surface of the second contact arm <NUM>.

The combustion heater <NUM> shown in <FIG> and <FIG> has a single tube support <NUM>. However, the combustion heater <NUM> in an embodiment may include multiple of the tube support <NUM>. The heat exchanger tubes <NUM> are supported within the AHU <NUM> by only the end plate <NUM> and the one or more tube support(s) <NUM>.

<FIG> shows a perspective view of the slidable tube support <NUM> and the adjacent tube support clips <NUM>, according to an embodiment. Dashed lines are provided in <FIG> to illustrate the positions of the leftmost column of heat exchanger tubes <NUM>. The support clips <NUM> can help ensure a desired vertical spacing is maintained between adjacent heat exchanger tubes <NUM> (e.g., vertically adjacent heat exchanger tubes <NUM>).

Each support clip <NUM> includes a first opening <NUM> and a second opening <NUM>. The first opening <NUM> is configured to fit around a first heat exchanger tube <NUM>, and while second opening <NUM> is configured to fit around a second adjacent heat exchanger tube <NUM>. In an embodiment, the first opening <NUM> and second opening <NUM> are configured to snap fit around their respective heat exchanger tube <NUM>. The support clip <NUM> also has a middle portion <NUM> disposed between its adjacent pair heat exchanger tubes <NUM>. The middle portion <NUM> is configured to restrict movement between the adjacent heat exchanger tubes <NUM>. For example, the middle portion <NUM> is a bent portion that acts as a spring that biases the adjacent heat exchanger tubes <NUM> to a predetermined relative vertical position (e.g., biased to a set predetermined distance between the adjacent heat exchanger tubes <NUM>).

Each support clip <NUM> in the plurality of adjacent tube support clips <NUM> couples a different set of heat exchanger tubes. The support clips <NUM> can overlap at least one heat exchanger tube <NUM>. For example, a first support clip 170A couples a first heat exchanger tube 136A to a second heat exchanger tube 136B, and a second support clip 170B couples the second heat exchanger tube 136B to a third heat exchanger 136B.

The slidable tube support <NUM> in <FIG> includes a contact arm <NUM> for each heat exchanger tube <NUM>. However, the sliding support <NUM> in an embodiment may not have a contact arm <NUM> for each heat exchanger tube <NUM>. In such an embodiment, the support clip(s) <NUM> can be used to couple a heat exchanger tube <NUM> without a contact arm <NUM> to a heat exchanger tube <NUM> with a contact arm <NUM>. The slidable tube support <NUM> can provide support to the heat exchanger tube <NUM> without a contact arm <NUM> via the supported heat exchanger tube <NUM> and said support clip(s) <NUM>.

<FIG> show the combustion heater <NUM> in various positions when being removed from the AHU <NUM>. Dashed lines are provided in <FIG> and <FIG> to illustrate the sides of the housing <NUM> that form the fan section <NUM> of the AHU <NUM>.

<FIG> shows the combustion heater <NUM> in a first position. The first position is the position in which the combustion heater <NUM> is installed in the AHU <NUM> and is ready for operation. The combustion heater <NUM> in the installed position is ready for operating to direct combustion gases through the heat exchanger tubes <NUM> and heats the air as it flows through the fan section <NUM>. The first position can also be referred to as the installed position. <FIG> also shows the combustion heater <NUM> in its installed position.

As shown in <FIG>, the channels 144A, 144B each extend between the front side <NUM> and the rear side <NUM> of the AHU <NUM>. Each of the channels 144A, 144B extending towards the opening <NUM> in the front side <NUM> of the AHU <NUM>. As shown in <FIG>, each of the channels 144A, 144B extends along its respective side wall <NUM>, <NUM> in a direction towards the opening <NUM> in the front side <NUM> of the AHU <NUM>. The end <NUM> of each channels 144A, 144B that faces towards the front side <NUM> is open. The brackets 146A, 146B also each extending in the depth direction (e.g., direction D<NUM>) of the fan section <NUM>.

<FIG> shows the combustion heater <NUM> in a second position. The second position is a position in which the combustion heater <NUM> is partially slidably removed from the AHU <NUM>. For example, the combustion heater <NUM> in <FIG> is slidably moved (e.g., pulled) through the opening <NUM> in the front side <NUM> of the AHU <NUM> to reach the second position shown in <FIG>. The combustion heater <NUM> is slidably moved in the direction D<NUM> from the first position (shown in <FIG>) into the second position (shown in <FIG>). The second position may allow, for example, a technician to more easily access and/or work on the combustion heater <NUM>.

<FIG> shows the combustion heater <NUM> in a third position. The third position is a position in which the combustion heater <NUM> is completely removed from the AHU <NUM>. For example, the combustion heater <NUM> in <FIG> and <FIG> is slidably moved (e.g., pulled) through the opening <NUM> in the front side <NUM> of the AHU <NUM> to reach the third position shown in <FIG>. The combustion heater <NUM> slidably moved in the direction D<NUM> from the second position (shown in <FIG>) into the second position (shown in <FIG>). In the removed position (shown in Figure 7D), the combustion heater <NUM> is completely separated from the AHU <NUM>.

In removing the combustion heater <NUM> from the AHU <NUM> (e.g., moving the combustion heater <NUM> into the completely removed position shown in <FIG>), the slidable tube support <NUM> slides out of the channels 144A, 144B. The retaining member <NUM> sliding out of the ends <NUM> of the channels 144A, 144B. This allows for easy removal of the combustion heater <NUM> from the AHU <NUM> by simply pulling it in the third direction D<NUM> from the AHU <NUM>. The slidable tube support <NUM> is configured to support the installed combustion heater <NUM> (e.g., vertically support the heat exchanger tubes <NUM> within the fan section <NUM>) while also allowing slidable movement and removal of combustion heater <NUM> from the AHU <NUM>. In an embodiment, the slidable tube support <NUM> is slidable in the depth direction D<NUM> such that is does not restrict movement of the combustion heater <NUM> along the depth direction D<NUM>.

In an embodiment, a slidable tube support system for an AHU <NUM> includes one or more of the slidable tube supports <NUM>. In an embodiment, the slidable tube support system for an AHU <NUM> includes one or more of the slidable tube supports <NUM> and one or more adjacent tube support clips <NUM>. For example, the slidable tube support system may include a plurality of the adjacent tube support clips <NUM>.

<FIG> is a rear perspective view of an embodiment of an AHU <NUM>. A panel <NUM> of the rear side <NUM> is opened and removed in <FIG>. The panel <NUM> covers an opening <NUM> in the rear side <NUM> of housing <NUM> for the fan section <NUM> of the AHU <NUM>. The opening <NUM> in the housing <NUM> can be for an upper portion of the fan section <NUM>. The top side <NUM> of the housing <NUM> of the AHU <NUM> (e.g., top side <NUM> in <FIG>) in <FIG> is also removed for illustration. For example, a panel <NUM> (shown in <FIG>) of the top side <NUM> is opened and removed in <FIG>. The panel <NUM> covers an opening <NUM> in the top side <NUM> of the housing <NUM> for the fan section <NUM> of the AHU <NUM>. In particular, the opening <NUM> is for the top of the fan section <NUM>.

The AHU <NUM> includes a fan assembly <NUM>. The fan assembly <NUM> operates to generate air flow through the housing <NUM> from the inlet 108A to the outlet 108B (obscured in <FIG>), as discussed above. The fan assembly <NUM> one or more fan(s) <NUM> and a fan frame <NUM>. The fan(s) <NUM> affixed to the fan frame <NUM>. For example, the fan frame <NUM> provides a support frame for the fan(s) <NUM>. As shown in <FIG>, the fan(s) of the fan assembly <NUM> are radial fan(s). A radial fan has an axial inlet and at least one radial outlet. The radial fan axially suctioning air into its blade and discharging the air in one or more radial direction(s). The shape of the fan section <NUM> can direct the air downward towards the heat exchanger tubes <NUM> and the outlet 108B.

The fan(s) <NUM> are configured to suction air from the inlet section <NUM> into the combustion suction <NUM>. As shown in <FIG>, the fan frame <NUM> can also define an inlet <NUM> for each fan(s) <NUM> to suction air from the inlet section <NUM>. During operation of the AHU <NUM>, fan(s) <NUM> generates the flow of air through the inlet section <NUM> and the fan section <NUM> as discussed above. In particular, the fan assembly <NUM> can be configured to blow air so that the air flows downward from the fan assembly <NUM> and across the heat exchanger tubes <NUM> of the combustion heater <NUM> (e.g., air flows downward in direction D<NUM> across the heat exchanger tubes <NUM> as shown in <FIG>). For example, the suction of the fan(s) <NUM> pulls air through the inlet 108A (obscured in <FIG>) into inlet section <NUM> and blows the air past the heat exchanger tubes <NUM> and out through the outlet 108B in the fan section <NUM>.

The housing <NUM> includes a pair of rails 250A, 250B for supporting the fan assembly <NUM>. The rails 250A, 250B disposed in the fan section <NUM>. Each of the rails 250A, 250B has a length L that extends between the front side <NUM> and the rear side <NUM> of the housing <NUM>. For example, the rails 250A, 250B each extending away from the opening <NUM> into the fan section <NUM>. The fan frame <NUM> includes a pair of grooves 236A, 236B. The grooves 236A, 236B configured to be placed on the rails 250A, 250B to couple the fan assembly <NUM> to the housing <NUM>.

<FIG> shows the fan assembly <NUM> in a first position. The first position is the installed position of the fan assembly <NUM>. The fan assembly <NUM> in its installed position is ready for operating to blow air from the inlet section <NUM> downward towards the heat exchanger tubes <NUM> of the combustion heater <NUM>. The fan assembly <NUM> is configured to be both slidably and liftably removable from the AHU <NUM> as discussed below. For example, the disposition of the grooves 236A, 236B of the fan assembly <NUM> to the rails 250A, 250B is configured to vertically support the fan assembly <NUM> within the AHU <NUM> while also allowing lifting and horizontal sliding of the fan assembly <NUM> sufficient to remove the fan assembly from the AHU <NUM>. In an embodiment, the AHU <NUM> can include one or more the sliding block(s) <NUM>. The sliding block(s) <NUM> are discussed in more detail below.

<FIG> shows a rear view of the fan assembly <NUM> disposed on the rails 250A, 250B. A portion of the top side <NUM> of the housing <NUM> that extends along the fan section <NUM> is illustrated in dashed lines in <FIG> for illustration purposes. The fan assembly <NUM> hangs from the rails 250A, 250B. The fan assembly <NUM> is slidable on the rails 250A, 250B. The grooves 236A, 236B disposed on the rails 250A, 250B such that the fan assembly <NUM> is slidably supported within AHU <NUM>. The configuration of the grooves 236A, 236B disposed on the rails 250A, 250B also allows for the fan assembly <NUM> to be lifted off of the rails 250A, 250B (e.g., does not limit upward movement of the fan assembly <NUM>).

As shown in <FIG>, the fan <NUM> includes an electrical motor <NUM>. The electrical motor <NUM> that drives the fan <NUM>. The AHU <NUM> can include one or more electrical wires (e.g., power supply wire(s), signal wire(s), and the like) (not shown) for operating the fan(s) <NUM>. The removal of the fan assembly <NUM> can include electrically decoupling the fan assembly <NUM> from the rest of the AHU <NUM>. For example, electrically decoupling the fan assembly <NUM> from the AHU <NUM> can include disconnecting the electrical wire(s) for the combustion heater <NUM>.

As shown in <FIG>, each of the rails 250A, 250B project upwards (e.g., in direction D<NUM>) towards the top side <NUM> of the housing <NUM>. For example, the rails 250A, 250B project upwards in the direction D<NUM>. The rails 250A, 250B shown in <FIG> project directly upward. In an embodiment, rails 250A, 250B may project upwards at an angle. In an embodiment, the grooves 236A, 236B of the fan assembly <NUM> are slotted onto the rails 250A, 250B of the housing <NUM>. For example, a first groove 236A is slotted onto a first rail 250A and a second groove 236B is slotted onto the second rail 250A.

As shown in <FIG>, the grooves 236A, 236B face downward away from the top side <NUM> of the housing <NUM>. For example, the grooves 236A, 236B face downwards in the direction D<NUM>. The grooves 236A, 236B shown in <FIG> face directly downwards. In an embodiment, the grooves 236A, 236B may face downwards at an angle. Each groove 236A, 236B forms a space that is enclosed on at least two sides. The grooves 236A, 236B as shown in <FIG> are enclosed on at least three sides. For example, the space in the grooves 236A, 236B in <FIG> are enclosed by a first side wall that extends upwardly, a second side that extends outwardly from the first side, and a third side that extends downwardly from the second side. This provides the grooves 236A, 236B with a U shaped cross section. The grooves 236A, 236B can hook over each of the rails 250A, 250B so as to also provide rigid support between the two rails 250A, 250B. For example, the grooves 236A, 236B being hooked over each of the rails 250A, 250B allows the fan assembly <NUM> to prevent the rails 250A, 250B from bowing away from each other.

In an embodiment, a groove 236A can be enclosed on just two sides. For example, the grooves 236A, 236B may not include the third side. In such an embodiment, the space formed by the groove 236A, 236B can be the space formed in the corner of the two intersecting sides. The groove in such an embodiment can be formed by a flange that extends horizontally outward from the fan frame <NUM>.

The fan assembly <NUM> is supported within the housing <NUM> so as to be liftably removable. The fan assembly <NUM> has a configuration that allows for the fan assembly <NUM> in its install position to be lifted (e.g., moved vertically upward in direction D<NUM>) out of the AHU <NUM> and its housing <NUM>. The liftably removable configuration of the fan assembly <NUM> allows for the fan assembly to be lifted from its install position to a position entirely outside of the AHU and its housing <NUM>. When the fan assembly <NUM> is to be removed (e.g., for repair, testing, replacement, and the like), the fan assembly <NUM> is configured from its installed position to liftable/movable in the upward direction D<NUM> to pass through the opening <NUM> in the top side <NUM> of the housing <NUM> to be entirely outside of the AHU <NUM> and its housing <NUM>.

<FIG> shows a partial top view of the fan assembly <NUM> disposed in the fan section <NUM>, according to an embodiment. The general position of the heat exchanger tubes <NUM> is schematically illustrated with dashed lines in <FIG>. The general position of the outlet 108A is also illustrated in <FIG>.

As similarly discussed above, the grooves 236A, 236B of the fan assembly <NUM> are slidably disposed on the rails 250A, 250B of the housing <NUM>. The grooves 236A, 236B are slidably disposed on the rails 250A, 250B such that the fan assembly <NUM> is slidable along the rails 250A, 250B. For example, the supported fan assembly <NUM> is configured to be slidable along the length L of the rails 250A, 250B in the direction D<NUM> towards the opening <NUM> in the housing <NUM>. The fan assembly <NUM> slides along the rails 250A, 250B to move the fan assembly <NUM> through the opening <NUM> in housing <NUM>.

As shown in <FIG>, the grooves 236A, 236B are disposed on opposite sides of the fan frame <NUM>. For example, the first groove 236A is located along the rear of the fan frame <NUM> and the second groove 236B is disposed along the front of the fan frame <NUM>. The grooves 236A, 236B in <FIG> have multiple sections. For example, the first groove 236A is non-continuous and has multiple sections disposed on the first rail 250A, 250B. In an embodiment, the grooves 236A, 236B may each have one or more sections.

The fan assembly <NUM> is slidably removable by having a configuration that allows for the fan assembly <NUM> to be slide from its installed position to a position outside of the AHU <NUM> and its housing <NUM>. For example, the fan assembly <NUM> from its installed position is slidable in the horizontal direction (e.g., in the direction D<NUM>) to an extent that allows for the fan assembly <NUM> to be moved entirely outside of the AHU <NUM> and its housing <NUM>.

In an embodiment, the AHU <NUM> may include one or more sliding block <NUM>. The sliding block(s) <NUM> restrict the sliding movement of the fan assembly <NUM> along the rails 250A, 250B. A sliding block <NUM> is disposed in the sliding path of the fan assembly <NUM>. The sliding block <NUM> limits the sliding of the fan assembly <NUM> along the rails 250A, 250B. For example, the groove 236A contacts the sliding block <NUM> and is stopped from sliding further in the direction D1. As shown in <FIG>, a sliding block 270A can be provided along one of the rails 250A, 250B between the fan assembly <NUM> and the opening <NUM> and/or between sections of one of the grooves 236A, 236B.

Operation of the AHU <NUM> can shake the fan assembly <NUM>. The operation of the fan(s) <NUM> can also apply directional forces to the fan assembly <NUM>. For example, operation of the fan(s) can apply a force in the first direction D1 to the fan assembly <NUM>. The sliding block(s) <NUM> can be used to limit/prevent sliding of the fan assembly <NUM> in their installed position during operation of the AHU <NUM>. For example, the sliding block(s) <NUM> preventing incidental sliding of the fan assembly <NUM> not related to removal of the fan assembly <NUM> (e.g., forces not applied by a technician (directly or mechanically) for sliding the fan assembly <NUM>). In an embodiment, the sliding removal of the fan assembly <NUM> can include detaching the slide blocks <NUM> to allow the full sliding movement and removal of the fan assembly <NUM>.

<FIG> is a rear perspective exploded view of a sliding block <NUM> for the fan assembly <NUM>, according to an embodiment. The sliding block <NUM> is configured to be detachably affixed to the housing <NUM> and/or to the fan assembly <NUM>. The sliding block <NUM> can have a first side <NUM> that is detachably affixed to the housing <NUM>. As shown in <FIG>, the first side <NUM> may be detachably affixed to the one of the rails 250A, 250B via a fastener <NUM> (screw, bolt, clamp, and the like). The sliding block <NUM> can have a second side <NUM> that is detachably affixed to the fan assembly <NUM>. For example, the second side <NUM> is detachably affixed to the fan frame <NUM> via a fastener <NUM> (e.g., screw, bolt, clamp, and the like), coupling, or the like. When the fan assembly <NUM> is to be removed, the sliding block <NUM> is detached from the fan assembly <NUM> and/or the housing <NUM>. In an embodiment, sliding removal of the fan assembly <NUM> can include removing one or more of the fasteners <NUM> to detach the sliding block <NUM> (e.g., unscrewing, pulling out, removing, and the like) from fan assembly <NUM> and/or the housing <NUM>.

<FIG> shows the separation of the fan assembly <NUM>. In an embodiment, the fan frame <NUM> of the fan assembly <NUM> is configured to be separable into multiple separate portions 238A, 238B as shown in <FIG>. Each of the portions 238A, 238B includes at least one fan <NUM>. The portions 238A, 238B can be coupled together via one or more removable fasteners (not shown) (e.g., screw, bolt, clamp, and the like). For example, the fan frame <NUM> is separable into a first frame portion 238A that includes a first fan 232A and a second frame portion 238B that includes a second fan 232B. The fan assembly <NUM> is separable into two portions in <FIG>. In an embodiment, the fan assembly <NUM> may include more than two fans <NUM> and be separable into more than two frame portions 238A, 238B. For example, the fan assembly <NUM> in an embodiment may include three or more fans <NUM> and be separable into three or more portions.

<FIG> show the fan assembly <NUM> in various positions during removal from the AHU <NUM>. <FIG> and <FIG> shows the fan assembly <NUM> when slidably removed from the AHU <NUM>. <FIG> shows the fan assembly <NUM> when liftably removed from the AHU <NUM>. As noted above, <FIG> shows the fan assembly <NUM> in the first position, which is its installed position.

<FIG> shows the fan assembly <NUM> in a second position. The second position is a position in which fan assembly <NUM> is partially slidably removed from the AHU <NUM>. For example, fan assembly <NUM> in <FIG> is slidably moved (e.g., pulled) through the opening <NUM> in the rear side <NUM> of the AHU <NUM> to reach its second position as shown in <FIG>. The fan assembly <NUM> is slidably moved along the rails 250A, 250B in the direction D<NUM> from the first position (shown in <FIG>) into the second position (shown in <FIG>). The second position may allow, for example, a technician to more easily access and/or work on the fan assembly <NUM>.

As shown in <FIG>, the first fan portion <NUM> is positioned outside of the AHU <NUM> when the fan assembly <NUM> is in the second position. In an embodiment, the second position allows for the first fan portion <NUM> to be detached and separated from the AHU <NUM>. For example, the first fan portion 238A is disposed outside the AHU <NUM> which can allow the first fan portion 238A to be separated from the rest of the fan assembly <NUM> (e.g., can allow the first fan portion 238A to be separated from the second fan portion 238B). The second position may advantageously allow, for example, a technician to remove the first fan portion 238A when there is limited room along the rear side <NUM> of the housing <NUM> (e.g., the rear side <NUM> is close to the side of a building, another AHU, or the like).

<FIG> shows the fan assembly <NUM> in a third position. The third position is a position in which fan assembly <NUM> is completely slidably removed from the AHU <NUM>. For example, the fan assembly <NUM> in <FIG> and/or <FIG> is slidably moved (e.g., pulled) through the opening <NUM> in the rear side <NUM> of the AHU <NUM> to reach the third position shown in <FIG>. The fan assembly <NUM> slidably moved in the direction D<NUM> from the first position (shown in <FIG>) to the third position (shown in <FIG>). The fan assembly <NUM> reaching and being moved from the second position (shown in <FIG>) as the fan assembly <NUM> is moved from the first position (shown in <FIG>) to the third position (shown in <FIG>). The second position in <FIG> can be an example of an intermediate position between the installed position and the completely slidably removed position. In the removed position (shown in <FIG>), the fan assembly <NUM> is completely separated from the AHU <NUM>.

The fan assembly <NUM> is configured to slide through an opening <NUM> in the rear side <NUM> of AHU <NUM>. In an embodiment, the sliding direction/removal direction of the fan assembly <NUM> may be invested. For example, the AHU <NUM> in an embodiment may be configured to have the fan assembly <NUM> configured to be slidably move through an opening in the front side <NUM> of housing <NUM> instead of the rear side <NUM>.

<FIG> shows the fan assembly <NUM> in a fourth position. The fourth position in <FIG> is a position in which fan assembly <NUM> is completely liftably removed from the AHU <NUM>. The fourth position can be referred to as a completely liftably removed position. For example, fan assembly <NUM> in the installed position (as shown in <FIG>) is moved upwardly (e.g., lifted, pulled upwards) through the opening <NUM> in the top side <NUM> of the AHU <NUM> to reach the fourth position shown in <FIG>. The fan assembly <NUM> is lifted/moved in the direction D<NUM> from the first position (shown in <FIG>) into the fourth position (shown in <FIG>).

When fan assembly <NUM> is configured to be capable of being both slidably removable and liftably removable from the AHU <NUM>. For example, the fan assembly <NUM> in the first position (as shown in <FIG>) is capable of sliding out of the AHU <NUM> to be removed and is capable of being lifted out of the AHU <NUM> to be removed. This duel removability of the fan assembly <NUM> advantageously allows removal through two different sides of AHU <NUM>. This can be advantageous when one side of an installed AHU is close to another object (e.g., a portion of a building, another AHU, and the like) that does not allow for removal through said side.

In an embodiment, the removable configuration of the fan assembly <NUM> may be employed in AHU <NUM> that does not include a combustion heater. For example, in such an embodiment, the AHU <NUM> may be configured to utilize a non-combustion type of heater or to not have a heating mode. In an embodiment, the removable configuration of the combustion unit <NUM> may be employed in an AHU <NUM> that does not utilize the liftably and slidably removable fan assembly. In such an embodiment, the AHU <NUM> may employ a conventional fan configuration for directing air through the fan section <NUM>.

Claim 1:
An air handling unit (AHU) (<NUM>, <NUM>) for a heating, ventilation, air conditioning, and refrigeration system, the air handling unit (<NUM>, <NUM>) comprising:
a housing (<NUM>) containing a combustion section (<NUM>), the housing (<NUM>) including: a first side (<NUM>) with a first opening (<NUM>) for the combustion section (<NUM>), a top side (<NUM>) with a second opening (<NUM>) for the combustion section (<NUM>), and a pair of rails (250a, 250b) disposed in the combustion section (<NUM>), and
a fan assembly (<NUM>) including one or more fans (<NUM>),
characterized in that the fan assembly (<NUM>) is disposed in the combustion section (<NUM>) and includes a pair of grooves (236a, 236b), the pair of grooves (236a, 236b) slidably disposed on the pair of rails (250a, 250b),
wherein the fan assembly (<NUM>) is configured to be both slidably removable from the AHU (<NUM>, <NUM>) through the first opening (<NUM>) in the housing (<NUM>) and liftably removable from the AHU (<NUM>, <NUM>) through the second opening (<NUM>) in the housing (<NUM>).