Patent Publication Number: US-11644217-B2

Title: Drain pan extension

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/427,694 filed May 31, 2019, by John Bauer et al., and entitled “DRAIN PAN EXTENSION,” which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to heating, ventilation, and air conditioning (HVAC) systems. In particular embodiments, this disclosure relates to a reconfigurable drain pan extension for use with a horizontal evaporator coil. 
     BACKGROUND 
     Heating, ventilation, and air conditioning (HVAC) systems are used to regulate environmental conditions within an enclosed space. HVAC systems include a horizontal evaporator coil for cooling and/or dehumidifying air and a blower that pulls warm air from the enclosed space and pushes the air across the horizontal evaporator coil before it is returned, as conditioned air, via one or more ducts to the enclosed space. During operation of the horizontal evaporator coil, water vapor from the warm air passing over the coil condenses on the surface of the coil. A drain pan can be placed below the horizontal evaporator coil to capture this water as it falls in a vertical direction from the coil, thereby limiting the risk of moisture damage to the underlying floor (e.g., an attic floor). However, under normal operating conditions liquid water on the evaporator coil can also be pushed in a horizontal direction by air flowing across the evaporator coil such that the water is not captured by the drain pan, resulting in damage to components of the HVAC system downstream from the evaporator coil and/or to the region surrounding the evaporator coil that is not protected by the drain pan (e.g., the floor surrounding the drain pan). There exists a need for improved apparatus for preventing the undesired spread of this liquid water from the evaporator coil. 
     SUMMARY OF THE DISCLOSURE 
     As described above, HVAC systems include an evaporator coil installed in a horizontal orientation or a “horizontal evaporator coil.” A horizontal evaporator coil for a residential HVAC system is installed in an attic space. A drain pan placed below the evaporator coil on the attic floor can generally capture liquid condensate as it drips in a vertical direction from the evaporator coil. However, the drain pan typically fails to capture liquid condensate that is pushed horizontally from the surface of the coil by air flowing through the HVAC system (i.e., air flowing across the evaporator coil). This liquid condensate that is pushed in a horizontal direction is sometimes referred to as evaporator “blow off” and can result in moisture damage (e.g., corrosion and/or growth of biological contamination such as mold) in both the HVAC system (e.g., the surface of ducts downstream from the evaporator coil) and the surroundings of the horizontal evaporator coil (e.g., the attic floor and/or the underlying portion of the ceiling in a room below the attic). 
     This disclosure contemplates an apparatus that includes a reconfigurable drain pan extension that can be coupled to a drain pan prior to its installation, and used to collect evaporator blow off from a horizontal evaporator coil to prevent damage to the region surrounding the coil. The apparatus, in certain embodiments, includes a drain pan configured to receive liquid condensate from a horizontal evaporator coil positioned above the drain pan and a drain pan extension coupled to the drain pan. The front and rear sides of the drain pan each includes a horizontal notch, and the front and rear sides of the drain pan extension each includes a pin that is fitted within and movable with the corresponding notch of the drain pan. The bottom surface of the drain pan extension includes one or more stoppers positioned such that the drain pan extension is securably configurable in (i) a first (e.g., transportation) configuration in which a surface of the drain pan extension is at or near an edge of the horizontal evaporator coil and (ii) a second (e.g., installation) configuration in which the one or more stoppers contact the left side of the drain pan so that a portion of the drain pan extension extends beyond the left side of the drain pan at a predefined angle relative to the drain pan. The predefined angle is generally selected for improved collection of evaporator blow off, based on the intended operating parameters of the evaporator coil and/or a corresponding HVAC system. 
     In the first configuration, the drain pan extension may provide protection to the horizontal coil when it is transported (e.g., from a point of manufacture or sale to a point of installation). The installer can then efficiently reconfigure and secure the drain pan extension from the first configuration to the second configuration, which facilitates effective capture of liquid condensate blow off from the horizontal evaporator coil based on the intended operating conditions of the coil and/or the overall HVAC system of which it is a part. 
     The second configuration may be determined by the length of the horizontal notches of the drain pan and/or the size and positioning of the stopper(s) on the drain pan extension. These parameters may be selected and designed at the time of manufacture to ensure the drain pan extension is in an evaporator-specific installation configuration, based on an anticipated amount and trajectory of liquid condensate in the evaporator blow off. For example, one or more stoppers on the drain pan may be of an appropriate height and positioned an appropriate distance from the edge of the extension on the bottom surface of the extension to facilitate the automatic and secure configuration of the drain pan extension at an appropriate angle for capturing liquid condensate from the evaporator blow off expected for an HVAC system rated for a given range of rates of air flow across the evaporator coil. As such, the apparatus of the present disclosure facilitates the straightforward adjustment of the drain pan extension to an evaporator-specific installation configuration based on known properties of the HVAC system and or the horizontal evaporator coil (e.g., expected maximum airflow rates through the horizontal evaporator coil, e.g., size of the horizontal evaporator coil, e.g., expected rate of liquid condensation on the horizontal evaporator coil). 
     Certain embodiments of the apparatus described herein include one or more additional locking mechanisms for further securing the extension in the first configuration during transport and/or for securing the extension in the second configuration after installation. For example, the locking mechanism may allow the drain pan extension to be attached in a reversible manner to the evaporator coil such that it securely protects the coil during its transport and yet is easily un-attached from the coil at the time of installation. This embodiment may provide further protection to the horizontal evaporator coil during its transport. 
     In certain embodiments, the drain pan extension can be configured at a plurality of angles such that a single extension can be used for a range of horizontal evaporator coil types and for a range of HVAC operating conditions. For example, different drain pan extension angles can be achieved using one or more additional stoppers on the bottom surface of the drain pan extension (e.g., as shown in  FIGS.  3 A-C ) or via one or more vertical grooves in the notch of the drain pan (e.g., as shown in  FIGS.  4 A-C ). 
     These one or more additional configurations of the drain pan extension may facilitate the installation of the apparatus with a wider variety of HVAC systems and/or in different environments. For example, an HVAC system with a large evaporator coil may have different evaporator blow off characteristics than a system with a relatively small evaporator coil, and the drain pan extension can be automatically configured during installation by simply selecting the appropriate configuration. Similarly, an HVAC system installed in a high humidity environment may have different evaporator “blow off” characteristics than a system installed in a relatively low humidity environment. Accordingly, the apparatus may be provided with instructions for appropriately configuring the drain pan extension based on the properties of the HVAC system and/or the local environment. This facilitates the straightforward installation and adjustment of the same apparatus for a variety of operating conditions. Moreover, the drain pan extension can be reconfigured as needed (e.g., between seasons) without requiring complicated maintenance activities (e.g., drilling through the drain pan). 
     In certain embodiments, the drain pan extension is constructed from a corrosion-resistant material such as a plastic or a corrosion resistant alloy. In some embodiments, the drain pan extension is constructed from the same material as the drain pan. 
     Certain embodiments may include none, some, or all of the above technical advantages. One or more other technical advantages may be readily apparent to one skilled in the art from the figures, descriptions, and claims included herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which: 
         FIGS.  1 A-C  are diagrams of the apparatus, according to an illustrative embodiment of the present disclosure; 
         FIGS.  2 A-C  are diagrams of the apparatus of  FIGS.  1 A-C  from perspective views; 
         FIGS.  3 A-C  are diagrams of the apparatus comprising additional stoppers with the drain pan extension in different configurations, according to an illustrative embodiment; and 
         FIGS.  4 A-C  are diagrams of the apparatus with the drain pan extension arranged in different configurations, according to an illustrative embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure and its advantages are best understood by referring to the drawings, like numerals being used for like and corresponding parts of the various drawings. 
       FIGS.  1 A-C  and  2 A-C show an example apparatus  100  according to the present disclosure.  FIGS.  1 A and  1 B  show apparatus  100  in a first configuration (e.g., a transportation configuration) and a second configuration (e.g., an installation configuration), respectively.  FIGS.  2 A-C  show perspective views of the apparatus  100  in the second (e.g., installation) configuration of  FIG.  1 B . 
     Apparatus  100  is generally configured to receive liquid condensate from an evaporator coil  112 , as shown in  FIGS.  1 A and  1 B . For example, the apparatus  100  may be placed below the evaporator coil  112  to receive liquid condensate from the coil  112 . Apparatus  100  includes a drain pan  102  disposed below the coil  112 , and a drain pan extension  110  attached to the drain pan  102 . The drain pan  102  has a first notch  104   a  (e.g., a front notch) and second notch  104   b  (e.g., a rear notch) such that a first pin  106   a  (e.g., the front pin) and a second pin  106   b  (e.g., the rear pin) of the drain pan extension  110  are fitted and slidably movable within the correspond notch of notches  104   a  and  104   b . The notches  104   a,b  and pins  106   a,b  generally facilitate adjustment of the drain pan extension  110  between two or more configurations, including the first (e.g., transportation) configuration and the second (e.g., installation) configurations shown in  FIGS.  1 A and  1 B , respectively. 
     The evaporator coil  112  may be a horizontal evaporator coil. The evaporator coil  112  may be positioned on or above and/or be attached to a top surface  134  of the base  122  of the drain pan  102 . For example, a base and/or other support of the evaporator coil  112  may be attached to the top surface  134  (see  FIGS.  2 A-C ) of the drain pan  102 , or a portion of the evaporator coil  112  may be allowed to rest on top of or within the drain pan  102 . The evaporator coil  112  may include one or more circuits for the flow of a working fluid (e.g., a refrigerant). The working fluid may be any acceptable working fluid including, but not limited to, fluorocarbons (e.g. chlorofluorocarbons), ammonia, non-halogenated hydrocarbons (e.g. propane), hydrofluorocarbons (e.g., R- 410 A), or any other suitable type of refrigerant. The evaporator coil  112  generally acts as a heat exchanger, providing heat transfer between air flowing across the coil  112  (i.e., contacting an outer surface of the evaporator coil  112 ) and working fluid passing through the interior of the evaporator coil  112 . In a typical HVAC system, the evaporator coil  112  is fluidically connected to a condenser and a compressor (not shown), such that cool liquid-phase working fluid flows from the condenser to the evaporator coil  112  and heated vapor-phase working fluid flows from the evaporator coil  112  to the compressor. 
     The drain pan  102  is generally configured to capture liquid condensate falling from the evaporator coil  112  (i.e., falling downward under the influence of gravity). The drain pan  102  may be made of a corrosion-resistance material such as a plastic or a corrosion-resistant alloy. The drain pan  102  includes a pan base  122 , a left pan side  120  extending along the left edge  150  of the pan base  122 , a right pan side  128  extending along the right edge  156  of the pan base  122 , a front pan side  124  extending along the front edge  152  of the pan base  122 , and a rear pan side  136  extending along the rear edge  154  of the pan base  122 . Each of the left pan side  120 , the right pan side  128 , the front pan side  124 , and the rear pan side  136  extends in an upward direction from the top surface  134  of the pan base  122  to form the drain pan  102 . Each of the sides  120 ,  124 ,  128 ,  136  may have a height of about 1 to 10 inches. Any one or more of the pan sides  120 ,  124 ,  128 ,  136  may have a different height as appropriate for collecting liquid condensate falling from the evaporator coil  112 . 
     The left pan side  120  of the drain pan  102  generally extends at least to the left edge  116  of the evaporator coil  112 . However, in preferred embodiments, the left pan side  120  of the drain pan  102  is positioned beyond the edge of the evaporator coil  112  by about 3 to 12 inches. The right pan side  128  of the drain pan  102  is generally similarly configured such that the right pan side  128  is at least positioned in line with the right edge  118  of the evaporator coil  112 . The front side  124  and rear side  136  of the drain pan  102  similarly extend at least to a front edge and rear edge of the evaporator coil  112  to capture condensed liquid falling therefrom. In some embodiments, the rear pan side  128 , front side  124 , and/or rear side  136  of the drain pan  102  extend about 3 to 12 inches from the corresponding edge of the evaporator coil  112 . 
     The front pan side  124  includes a first horizontal notch  104   a , and the rear pan side  136  includes a second horizontal notch  104   b . The horizontal notches  104   a,b  generally facilitate coupling of the drain pan extension  110  to the drain pan  102 . Each notch  104   a,b  may have an approximately rectangular or rounded rectangular shape. As shown in  FIG.  2 C , notch  104   a  extends along a portion of the front pan side  124 . The notch  104   a  may extend from a distance  172  (e.g., of about 0.1 inch) from the left edge  150  of the base  122  of the drain pan  102  (e.g., from the left pan side  120 ) to less than the entire length  174  of the front pan side  124 . As shown in  FIG.  2 B , a similar notch  104   b  is in the rear side  136  of the drain pan  102 . In some embodiments, the notches  104   a,b  extend for less than about 25% of the length of the front pan side  124 . In some embodiments, the length of each of notches  104   a,b  is in range from about 0.5 to 8 inches. The height of each of notches  104   a,b  may be in range from about 0.1 to about 3 inches. 
     The drain pan extension  110  is slidably coupled to the drain pan  102  via pins  106   a,b  that are fitted and movable within the horizontal notches  104   a,b  of the drain pan  102 . The drain pan extension  110  is generally configured to capture liquid condensate falling from the evaporator coil  112  that is pushed horizontally by air flowing across the coil  112  (i.e., in the leftward direction in the view of  FIGS.  1 A-B  and  2 A-C). The drain pan extension  110  is movable between and securable in the first (e.g., transportation) configuration shown in  FIG.  1 A  and the second (e.g., installation) configuration shown in  FIG.  1 B . The drain pan extension  110  may be made of a corrosion-resistant material such as a plastic or a corrosion-resistant alloy. In some embodiments, the drain pan extension  110  is made of the same material as that of the drain pan  102 . 
     The drain pan extension  110  includes a base  138 , a front side  144  extending along the front edge  160  of the base  138 , an optional left side  148  extending along the left edge  164  of the base  138 , and a rear side  146  extending along the rear edge  162  of the base  138 . Each of sides  144 ,  146 , and  148  extends vertically from (e.g., normal to, or approximately perpendicular to) the top surface  140  of the base  138  of the drain pan extension  110 . The drain pan extension  110  may have a length  130  ( FIG.  1 B ) similar to the height of the leftmost edge  116  of the evaporator coil  112  and a width  170  ( FIG.  2 C ) similar to the width of the drain pan  102 . For example, the length  130  of the drain pan extension  110  may be between about 6 and 36 inches, and the width of the drain pan extension  110  may be between about 6 and 36 inches. 
     The front side  144  and rear side  146  of the drain pan extension  110  include pins  106   a  and  106   b , respectively, that facilitate coupling of the drain pan extension  110  to the drain pan  102  via notches  104   a,b . As shown in  FIGS.  2 A-B , the pins  106   a,b  are generally positioned an equal distance (e.g., of at least 0.1 inch) from the right edge  158  of the base  138  of the drain pan extension  110 . The pins  106   a,b  are fitted and horizontally movable within the corresponding notches  104   a,b  of the drain pan  102 . The pins  106   a,b  may be any appropriate protrusions for fitting into and moving within the corresponding notches  104   a,b  of the drain pan  102 . For example, the pins  106   a,b  may be sized and shaped to fit and move within the notches  104   a,b . In some embodiment, an end cap or cover may be affixed to the end of one or more of the pins  106   a,b  to prevent the pins  106   a,b  from being removed from the corresponding notch  104   a,b  and to further facilitate the secure coupling of the drain pan extension  110  to the drain pan  102 . 
     The bottom surface  142  of the drain pan extension  110  includes stoppers  108  ( FIG.  2 C ) positioned a predefined distance  176  ( FIG.  1 B ) from the right edge  158  ( FIG.  2 A-B ) of the base  138  of the drain pan extension  110  such that the drain pan extension  110  is securably configurable in the first configuration shown in  FIG.  1 A  and the second configuration shown in  FIG.  1 B . The stoppers  108  protrude from the bottom surface  142  of the drain pan extension  110  and facilitate securing the drain pan extension  110  in the predefined second (e.g., installation) configuration shown in  FIG.  2 B . The stoppers  108  may include a securing mechanism such as a clasp or lock to further secure the drain pan extension in the second configuration. For instance, a clasp on one of stoppers  108  may be attached to the left side  120  of the drain pan  102  or to a surface on which the drain pan  102  is placed. While the illustrative example of  FIGS.  1 A-B  and  2 A-C show cylindrically shaped stoppers  108 , it should be understood that any other stopper shape or type may be used without departing from the scope of the present disclosure. 
     Now referring to  FIG.  1 A , in the first (e.g., transportation) configuration, the drain pan extension  110  is generally configured at a predetermined angle  126  that is equal to or greater than 90°. For example, angle  126  may be between 90° and 180°. Angle  126  is generally determined by the extent to which the drain pan  102  extends beyond the edge  116  of the evaporator coil  112 , the height of the evaporator coil  112  above the drain pan  102 , and/or the positions of notches  104   a,b  and pins  106   a,b . In the first (e.g., transportation) configuration shown in  FIG.  1 A , the drain pan extension  110  may rest against the edge  116  of the evaporator coil  112 . In some embodiments, the drain pan extension  110  and/or the evaporator coil  112  includes a securing mechanism  114  that is operable to secure the drain pan extension  110  to the edge  116  of the evaporator coil  112 . The securing mechanism  114  may be any appropriate clasp, lock, or adapter for securably attaching the drain pan extension  110  to the evaporator coil  112 . For example, the securing mechanism  114  may be a clasp that is attached to the evaporator coil  112  to secure the drain pan extension  110  in the first configuration shown in  FIG.  1 A . In some embodiments, the securing mechanism  114  is a temporary securing mechanism (e.g., a removable tie) that is removed and discarded after installation. 
     During installation, the drain pan extension  110  is moved and/or rotated to the second configuration shown in  FIG.  1 B . In the second configuration, the drain pan extension  110  may be at an angle  132  relative to the top surface  134  of the base  122  of the drain pan  102 . Angle  132  may generally be any angle that is appropriate for capturing liquid condensate blow off from the evaporator coil  112 . In certain embodiments, angle  132  is less than or equal to 45°. In some embodiments, the angle  132  is between about 10° and 20°. 
     Generally, angle  132  may be determined based on properties of the evaporator coil  112  and/or of an HVAC system associated therewith. For example, angle  132  may be determined based on a known range of rates of airflow across the evaporator coil  112 , because the rate of airflow will determine the distance traveled in a horizontal direction by liquid condensate on the surface of the evaporator coil  112 . The angle  132  may be determined based on the height and/or type of the evaporator coil  112 . For example, if the height of the evaporator coil  112  relative to the drain pan  102  is increased, the value of angle  132  may be increased to facilitate capture of liquid condensate blow off from the coil  112 . A selected value for angle  132  is then determined based on one or more of the length of the horizontal notches  104   a,b , the position of stoppers  108  on the bottom surface  142  of the drain pan extension  110 , and the height of stoppers  108 . The relationship between angle  132  and the configuration of various components of the apparatus  100  is described in greater detail below with respect to  FIGS.  3 A-C . 
     Referring to  FIG.  1 B , during an example operation of the apparatus  100  (e.g., during operation of an HVAC system comprising the evaporator coil  112  and the apparatus  100 ), warm air flows across the evaporator coil  112  and is cooled via heat transfer with the working fluid flowing through the evaporator coil  112 . During this heat transfer, liquid condensate (i.e., liquid water) may form on the outer surface of the evaporator coil  112 . This liquid condensate can fall downwards (i.e., in a vertical direction) and/or be pushed horizontally (e.g., to the left in the view of  FIGS.  1 A and  1 B ) by air flowing across the evaporator coil  112 . In the absence of the drain pan extension  110 , at least a portion of the liquid condensate pushed horizontally by the air flow may not be captured by the drain pan  102 , resulting in possible damage to the underlying surface. When the drain pan extension  110  is present, as in apparatus  100 , this liquid condensate is captured and redirected into the drain pan  102 , preventing or significantly reducing damage to the underlying surface. 
     The length  130  and angle  132  of the drain pan extension  110  in the second configuration shown in  FIG.  1 B  may be determined at the time of manufacture to ensure the drain pan extension can be secured in a predetermined installation configuration, based on an anticipated amount and trajectory of liquid condensate in the evaporator blow off. As described above, by providing the preconfigured installation configuration shown in  FIG.  1 B , the apparatus  100  facilitates appropriate placement of drain pan extension  110  without risk of installer error and without requiring after-market modification and possible damage to the drain pan  102 . 
     While  FIGS.  1 A-B  show the apparatus  100  in a “left-hand” configuration in which the drain pan extension  110  of the apparatus  100  extends to the left relative to coil  112 , it should be understood that the apparatus can be installed in a “right-hand”configuration in which the drain pan extension  110  extends to the right relative to coil  112 . For example, the apparatus  100  can be rotated to accommodate the right-hand configuration shown in  FIG.  1 C . 
       FIGS.  3 A-C  show an example of a portion  300  of an apparatus that is configurable in multiple installation configurations (i.e., at multiple predetermined installation angles). For example portion  300  may be a portion of apparatus  100  shown in  FIGS.  1 A-B  and  2 A-C, described above. Accordingly, as would be understood by one skilled in the art, drain pan  305  and drain pan extension  325  may include each of the parts and features of drain pan  102  and drain pan extension  110 , respectively, described above with respect to  FIGS.  1 A-B  and  2 A-C. In the illustrative examples of  FIGS.  3 A-C , the different configurations are realizable using stoppers  320   a - c . The apparatus includes the same features and components described with respect to apparatus  100  above. However, in the portion  300  of the apparatus shown in  FIGS.  3 A-C , the bottom surface of the drain pan extension  325  includes stoppers  320   a - c  at different distances from the right edge of the base of the drain pan extension  325 . Each of the stoppers  320   a - c  facilitates configuration of the drain pan extension  325  in a different installation configuration, which may be selected to improve capture of liquid condensate from an evaporator coil. 
       FIG.  3 A  shows the drain pan extension  325  in a first installation configuration. In this configuration, the pin  315  is near the left edge of notch  310  such that there is a relatively short distance  365  between pin  315  and the left side of the drain pan  305 . The drain pan extension  325  is held in the first installation configuration by stopper  320   a . The angle  330  between the drain pan extension  325  and the drain pan  305  is determined, based on geometric considerations, by the height  360  of the drain pan  305  relative to the notch  310  and the distance  365 . For instance, the tangent of angle  330  is approximately given by height  360  divided by distance  365 . When the ratio of height  360  to distance  365  is large (i.e., corresponding to the case where the pin  315  is near the left side of the drain pan  305  as in  FIG.  3 A ), the value of angle  330  is relatively large. Accordingly, in the first installation configuration shown in  FIG.  3 A , the drain pan extension  325  is at a relatively large angle  330 . 
       FIG.  3 B  shows the drain pan extension  325  in a second installation configuration. The drain pan extension  325  is held in the second installation configuration by stopper  320   b . Stopper  320   b  is a greater distance from the right edge of the drain pan extension  325  than is stopper  320   a . In this configuration, the pin  315  is near the center of notch  310  such that there is a longer distance  370  between pin  315  and the left side of the drain pan  305 , compared to the first configuration shown in  FIG.  3 A . Because of the same geometric considerations described above, in the second installation configuration shown in  FIG.  3 B , the drain pan extension  325  is at a smaller angle  340  relative to angle  330  shown in  FIG.  3 A . 
     Similarly,  FIG.  3 C  shows the drain pan extension  325  in a third installation configuration with the pin  315  near the right edge of notch  310  such that there is an even longer distance  375  between pin  315  and the left side of the drain pan  305 , compared to distances  365  and  370  of  FIGS.  3 A and  3 B . The drain pan extension is held in the third installation configuration by stopper  320   c . Stopper  320   c  is a greater distance from the right edge of the drain pan extension  325  than is stopper  320   b . Because of the same geometric considerations described above, in the third installation configuration shown in  FIG.  3 C , the drain pan extension  325  is at a smaller angle  350  relative to angle  340  shown in  FIG.  3 B . 
       FIGS.  4 A-C  shows a portion  400  of an alternative apparatus that is configurable in multiple installation configurations (i.e., at multiple installation angles). For example portion  400  may be a portion of apparatus  100  shown in  FIGS.  1 A-B  and  2 A-C, described above. Accordingly, as would be understood by one skilled in the art, drain pan  405  and drain pan extension  425  may include each of the parts and features of drain pan  102  and drain pan extension  110 , respectively, described above with respect to  FIGS.  1 A-B  and  2 A-C. However, in the portion  400  of the apparatus shown in  FIGS.  4 A-C , each of the notches  104   a,b  of apparatus  100  are replaced with a notch  410  with one or more vertical grooves  420   a - c , and the one or more stoppers  108  of apparatus  100  are optional. In the illustrative examples of  FIGS.  4 A-C , the different configurations are realizable using vertical grooves  420   a - c , which are configured to secure pin  415  in the first installation configuration of  FIG.  4 A  (at angle  430 ), the second installation configuration of  FIG.  4 B  (at angle  440 ), and the third installation configuration of  FIG.  4 C  (at angle  450 ). In general, angle  430  is greater than angle  440 , and angle  440  is greater than angle  450 . The drain pan extension  425  may be securely configured without including one or more stoppers (e.g., such as stoppers  108  of  FIGS.  1 A and  1 B ) on the bottom surface of the base of the drain pan extension  425 . However, in some embodiments, the drain pan extension  425  further includes stoppers on the bottom surface of the base of the drain pan extension  425  (e.g., stoppers  108  shown in  FIGS.  1 A-B  and  2 A-C). 
       FIG.  4 A  shows the drain pan extension  425  in a first installation configuration. In this configuration, the pin  415  is near the left edge of notch  410  and fitted within vertical groove  420   a  such that there is a relatively short distance between pin  415  and the left side of the drain pan  405 . The drain pan extension  425  is held in the first installation configuration by groove  420   a . The angle  430  between the drain pan extension  425  and the drain pan  405  is determined by the height of the drain pan relative to the notch  410  and the distance from the groove  420   a  to the left edge of the drain pan  405 . Accordingly, in the first installation configuration shown in  FIG.  4 A , the drain pan extension  425  is at a relatively large angle  430 . 
       FIG.  4 B  shows the drain pan extension  425  in a second installation configuration. The drain pan extension  425  is held in the second installation configuration by groove  420   b . Groove  420   b  is a greater distance from the right edge of the drain pan extension  425  than is groove  420   a . In this configuration, the pin  415  is near the center of notch  410  and fitted within groove  420   b  such that there is a longer distance between pin  415  and the left side of the drain pan  405 , compared to the first configuration shown in  FIG.  4 A . Accordingly, in the second installation configuration shown in  FIG.  4 B , the drain pan extension  425  is at a smaller angle  440  relative to angle  430  shown in  FIG.  4 A . 
     Similarly,  FIG.  4 C  shows the drain pan extension  425  in a third installation configuration with the pin  415  near the right edge of notch  410  and fitted within groove  420   c  such that there is a longer distance between pin  415  and the left side of the drain pan  405 , compared to the distances of  FIGS.  4 A and  4 B . The drain pan extension  425  is held in the third installation configuration by vertical groove  420   c , which is a greater distance from the right edge of the drain pan extension  425  than is groove  420   b . Because of the same geometric considerations described above, in the third installation configuration shown in  FIG.  4 C , the drain pan extension  425  is at a smaller angle  450  relative to angle  440  shown in  FIG.  4 B . 
     While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods might be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented. 
     In addition, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as coupled or directly coupled may be indirectly coupled. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein. 
     To aid the Patent Office, and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants note that they do not intend any of the appended claims to invoke 35 U.S.C. § 112(f) as it exists on the date of filing hereof unless the words “means for” or “step for” are explicitly used in the particular claim.