Patent Publication Number: US-2021189722-A1

Title: Pre-cast concrete flooring systems and methods of use

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application No. 62/467,878, filed Mar. 7, 2017, and entitled “Pre-Case Concrete Flooring Systems and Methods of Use,” the content of which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Most multi-story buildings are very wasteful of the space between the finished ceiling of one level and the finished floor of the level above it. This volume is referred to as the “sandwich volume.” Various building systems are routed through the sandwich volume, including HVAC, electrical, communications, plumbing, and fire protection. 
     To make the design process simpler, the design team often allocates an independent volume to each of the systems.  FIG. 1  illustrates a typical example of the sandwich volume. The structural, HVAC and lighting systems have been given their own volumes, having a horizontal extent equal to the footprint of the building and a vertical dimension great enough to accommodate the deepest component of each system. In this process, vast amounts of the interstitial volume are filled only with air. The overall height of the interstitial space is typically 5 to 6 feet in multistory office buildings. 
     Accordingly, there is a need in the art for a flooring system that allows for more efficient use of the sandwich volume. 
     BRIEF SUMMARY 
     Various implementations include an elongated pre-cast concrete floor support unit. The floor support unit comprises a first wall, a second wall, a third wall, a first web extending between the first wall and the second wall, and a second web extending between the first wall and the third wall. The second and third walls are coplanar and lie in a plane that is parallel and spaced apart from the first wall. The first and second webs are spaced apart from each other. And, the first wall and the first and second webs define a channel therebetween. 
     In some implementations, the floor support unit further comprises a first flange and a second flange. The first flange extends from an intersection of the first wall and the first web in the plane of the first wall, and the second flange extends from an intersection of the first wall and the second web in the plane of the first wall. 
     In some implementations, the first wall includes a first surface and a second surface. The first and second surfaces are opposite and spaced apart from each other. The first surface faces a first vertical direction, and the second surface faces a second vertical direction that is opposite from the first vertical direction. Each of the first and second webs has a first surface and a second surface. The first and second surfaces of the webs are opposite and spaced apart from each other, and the first surfaces of the first and second webs and the first wall define the channel. Each of the second and third walls has a first surface that faces the first vertical direction and a second surface that is opposite and spaced apart from the first surface of each of the second and third walls and faces the second vertical direction. And, thermally insulating material is disposed on at least a portion of the first surfaces of the first and second webs and the first, second, and third walls. For example, in some implementations, the thermally insulating material comprises at least one of a fiber reinforcing polymer material or sprayed foam insulation. 
     In some implementations, the unit has a first edge and a second edge, and first and second surfaces of each wall and web extend between the first edge and the second edge. The first edge of the channel is in fluid communication with a return air duct for a heating, ventilation, and air conditioning (HVAC) system, and the return air is received through the channel. 
     In some implementations, the first web lies at an angle of between 90° and 135° to the first wall. 
     In some implementations, the second web lies at an angle of between 90° and 135° to the first wall. 
     In some implementations, the concrete comprises pre-stressed tendons. 
     Various other implementations include a pre-cast concrete floor support system that comprises at least a first elongated floor support unit and a second elongated floor support unit. Each unit includes: a first wall; a second wall; a third wall; a first web extending between the first wall and the second wall; and a second web extending between the first wall and the third wall. The second and third walls are coplanar and lie in a plane that is parallel and spaced apart from the first wall, and the first and second webs are spaced apart from each other. The first wall and the first and second webs define a channel therebetween. A distal edge of the third wall of the first elongated floor support unit abuts against a distal edge of the second wall of the second elongated floor support unit, and the distal edges of the second and third walls are spaced apart from the first and second webs, respectively. The channel defined by the first wall and the first and second webs of each elongated floor support unit is a first channel and faces a first vertical direction, and a second channel is defined by the third wall and the second web of the first elongated floor support unit and the abutting second wall and the first web of the second elongated floor support unit. The second channel faces a second vertical direction that is opposite from the first vertical direction. 
     In some implementations, each elongated floor support unit further comprises a first flange and a second flange. The first flange extends from an intersection of the first wall and the first web in the plane of the first wall, and the second flange extends from an intersection of the first wall and the second web in the plane of the first wall. 
     In some implementations, the first wall of each elongated floor support unit includes a first surface and a second surface. The first and second surfaces are opposite and spaced apart from each other. The first surface faces a first vertical direction, and the second surface faces a second vertical direction that is opposite from the first vertical direction. Each of the first and second webs of each elongated floor support unit has first surface and a second surface, and the first and second surfaces of the webs are opposite and spaced apart from each other. The first surfaces of the first and second webs and the first wall define the channel. Each of the second and third walls of each elongated floor support unit has a first surface that faces the first vertical direction and a second surface that is opposite and spaced apart from the first surface of each of the second and third walls and faces the second vertical direction, and thermally insulating material is disposed on at least a portion of the first surfaces of the first and second webs and the first, second, and third walls. 
     In some implementations, the second channel distributes supply air from a heating, ventilation, and air conditioning (HVAC) system for a second level of a building, and the first channel receives return air for the HVAC system from a first level of the building, the first level being vertically below and adjacent the second level. 
     In some implementations, each elongated floor support unit has a first edge and a second edge, and first and second surfaces of each wall and web of each elongated floor support unit extend between the first edge and the second edge. One of the first or second edges of the first channel is in fluid communication with at least one return air inlet for the HVAC system, and the return air flows through the first channel. One of the first or second edges of the second channel is in fluid communication with at least one supply air outlet for the HVAC system, and the supply air flows through the second channel. 
     In some implementations, the first web of each elongated concrete floor support unit lies at an angle of between 90° and 135° to the first wall. 
     In some implementations, the second web of each elongated concrete floor support unit lies at an angle of between 90° and 135° to the first wall. 
     In some implementations, the concrete comprises pre-stressed tendons. 
     In some implementations, each flange defines a plurality of recessed portions along a distal edge of each flange. The distal edge extends a first distance from the web from which the flange extends, and each recessed portion has a distal edge that extends a second distance from the web from which the flange extends. The first distance is greater than the second distance. The distal edge of the second flange of the second elongated concrete floor support unit abuts the distal edge of the first flange of the first elongated concrete floor support unit, and the recessed portions defined by each edge align and define an opening through which supply air flows. 
     In some implementations, each of the second wall and third wall defines a plurality of recessed portions along a distal edge of each of the second wall and the third wall. The distal edge extends a first distance from the web from which the second or third wall extends, and each recessed portion has a distal edge that extends a second distance from the web from which the second or third wall extends. The first distance is greater than the second distance. The distal edge of the second wall of the second elongated concrete floor support unit abuts the distal edge of the first wall of the first elongated concrete floor support unit, and the recessed portions defined by each distal edge align and define an opening through which supply air flows. 
     In various other implementations, an elongated pre-cast concrete floor support unit includes: a first wall; a second wall; a third wall; a fourth wall; a first web extending between the first wall and the second wall; a second web extending between the first wall and the third wall; and a third web extending between the third wall and the fourth wall. The second and third walls are coplanar, the first and fourth walls are coplanar, the first, second, and third webs are spaced apart from each other, the second and third walls lie in a plane that is parallel and spaced apart from the first and fourth walls, the first and second webs and the first wall define a first channel therebetween, and the third wall and the second and third webs define a second channel therebetween. The first channel opens in a first vertical direction, and the second channel opens in a second vertical direction that is opposite of the first vertical direction. 
     In some implementations, the unit further comprises a first flange and a second flange. The first flange extends from an intersection of the first wall and the first web in the plane of the first wall, and the second flange extends from an intersection of the first wall and the second web in the plane of the first wall. 
     In some implementations, the unit further comprises a third flange that extends from an intersection of the fourth wall with the third web in the plane of the fourth wall. 
     In some implementations, the first, second, third, and fourth walls each include a first surface and a second surface. The first and second surfaces are opposite and spaced apart from each other. The first surface faces a first vertical direction, and the second surface faces a second vertical direction that is opposite from the first vertical direction. Each of the first, second, and third webs has a first surface and a second surface. The first and second surfaces of the webs are opposite and spaced apart from each other, and the first surfaces of the first and second webs and the first wall define the first channel, and the second surfaces of the second and third webs and the third wall define the second channel. Thermally insulating material is disposed on at least a portion of the first surfaces of the first, second, and third webs and the first, second, third, and fourth walls. 
     In some implementations, the unit has a first edge and a second edge, and first and second surfaces of each wall and web extend between the first edge and the second edge. One of the first or second edges of the first channel is in fluid communication with at least one return air inlet for a heating, ventilation, and air conditioning (HVAC) system, and the return air is received through the first channel. And, one of the first or second edges of the second channel is in fluid communication with a supply air outlet for the HVAC system, and supply air is received through the second channel. 
     In some implementations, the second channel provides supply air to a second level of a building, and the first channel receives return air from a first level of the building, wherein the first level is vertically adjacent and below the second level. 
     In some implementations, the first web lies at an angle of between 90° and 135° to the first wall. 
     In some implementations, the second web lies at an angle of between 90° and 135° to the first wall. 
     In some implementations, the third web lies at an angle of between 90° and 135° to the fourth wall. 
     In some implementations, the unit further includes a fifth wall and a fourth web, the fifth wall being coplanar with the second and third walls, wherein fourth web is spaced apart from the first, second, and third webs, the fourth web extends between the fourth wall and the fifth wall, and the third and fourth webs and the fourth wall define a third channel therebetween that opens in the first vertical direction. In some implementations, the fourth web lies at an angle of between 90° and 135° to the fourth wall. 
     In some implementations, the unit further includes a fourth flange that extends from an intersection of the fourth wall with the fourth web in the plane of the fourth wall. 
     And, in some implementations, the concrete comprises pre-stressed tendons. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a typical sandwich volume in a building according to the prior art. 
         FIG. 2  illustrates an end view of a floor support unit according to one implementation. 
         FIG. 3  illustrates a partial cross-sectional view of two of the floor support units shown in  FIG. 2  disposed horizontally adjacent each other. 
         FIG. 4  illustrates a cross sectional view of two floor support units shown in  FIG. 2  disposed horizontally adjacent each other. 
         FIG. 5  illustrates a perspective view of a plurality of the floor support units shown in  FIG. 2  installed in a building according to one implementation. 
         FIG. 6A  illustrates a partial perspective view of a plurality of floor support units installed in a building according to another implementation. 
         FIG. 6B  illustrates a cross sectional view of two of the floor support units shown in  FIG. 6A  as taken through the B-B line shown in  FIG. 6A . 
         FIG. 6C  illustrates a cross sectional view of two of the floor support units shown in  FIG. 6A  as taken through the A-A line shown in  FIG. 6A . 
         FIG. 7A  illustrates a partial perspective view of a plurality of floor support units installed in a building according to one implementation. 
         FIG. 7B  illustrates a cross sectional view of two of the floor support units shown in  FIG. 7A  as taken through the A-A line shown in  FIG. 7A . 
         FIG. 7C  illustrates a cross sectional view of two of the floor support units shown in  FIG. 7A  as taken through the B-B line shown in  FIG. 7A . 
         FIG. 8  illustrates the floor support units shown in  FIG. 6A  and a pedestal floor system. 
         FIG. 9  illustrates the floor support units and pedestal floor system of  FIG. 8  and supply and return ducts installed adjacent one end of a building, according to one implementation. 
         FIG. 10  illustrates the floor support units and pedestal floor system of  FIG. 8  and supply and return ducts installed adjacent a side of a building, according to one implementation. 
         FIG. 11  illustrates the floor support units and pedestal floor system of  FIG. 8  and supply and return ducts installed within an interior volume in a building, according to one implementation. 
         FIG. 12  illustrates a floor support unit according to another implementation. 
         FIG. 13  illustrates a floor support unit according to another implementation. 
     
    
    
     DETAILED DESCRIPTION 
     Various implementations include a corrugated concrete floor system that includes a plurality of elongated pre-cast concrete floor support units disposed in a horizontal arrangement relative to each other. The concrete floor support units are disposed between floors of a multi-story building. The units define a plurality of supply air plenums and return air plenums that are arranged alternately in the sandwich space between each floor. The supply air plenums are in fluid communication with the building level above them, and the return air plenums are in fluid communication with the building level below them. By having the supply-air plenum and the return-air plenum share the volume occupied by concrete floor support units, the height of the sandwich space is reduced. 
     In addition, various implementations of the floor system provide thermal comfort and good air quality by providing a continuous supply air plenum that delivers fresh, thermally conditioned air upward through the floor surface to the occupied space above and a continuous return air plenum that removes stale air through the ceiling of the occupied space below. In the occupied spaces, gently rising ventilation air assures comfort and maximizes air quality by taking off the most contaminated air at the ceiling. 
     The height of the sandwich space is also reduced by providing a top flange cross sectional area and an extensive bottom flange cross sectional area that provides a favorable cross-sectional area for the floor unit. The top flange increases the section modulus and moment of inertia of the floor unit and provides a working surface for construction activities and a support surface on which to mount an elevated access flooring that is used to enclose the supply plenum and provide a level, finished floor for the building occupants. In addition, the top flanges may be coupled together intermittently to complete the floor diaphragm. 
     By reducing the sandwich space, each floor of the building can have higher ceilings, and/or the overall height of the building can be reduced. Higher ceilings can provide lighter, more cheerful spaces and deeper penetration of natural light, which can reduce lighting electricity consumption. And, a lower building height decreases the cost of the building envelope area, reduces energy operating costs associated with energy losses through a thermal envelope of the building, and reduces the cost of additional structure that may be required to resist overturning moments due to wind and/or seismic activity. 
     In addition, by forming the units with concrete, the units provide full fire separation between building stories. Thus, no separate concrete topping layer is required. And, the system is compatible with steel-frame and pre-cast concrete-frame construction, which eliminates site-cast concrete and simplifies and speeds up the construction process. 
     Various implementations of the concrete floor system are applicable to any multi-story building. For example, the concrete floor system may be used in commercial, retail, residential, or industrial buildings. 
       FIG. 2  illustrates an elongated pre-cast concrete floor support unit  10  that includes a first wall  12 , a second wall  14 , a third wall  16 , a first web  18 , and a second web  20 . The second  14  and third walls  16  are coplanar and lie in a plane that is parallel and spaced apart from the first wall  12 . The first web  18  extends between the first wall  12  and the second wall  14 , and the second web  20  extends between the first wall  12  and the third wall  16 . The first web  18  and the second web  20  are spaced apart from each other, and the first wall  12  and the first  18  and second webs  20  define a channel  26  therebetween. In some implementations, each of the first web  18  and second web  20  lies at an angle Θ of between 90° and 135° to the first wall  12 . 
     The first wall  12  includes a first surface  32  and a second surface  34 , and the first  32  and second surfaces  34  are opposite and spaced apart from each other. The first surface  32  faces a first vertical direction, and the second surface  34  faces a second vertical direction that is opposite from the first vertical direction. In addition, each of the first  18  and second webs  20  has a first surface  36  and a second surface  38 , and the first  36  and second surfaces  38  of the webs  18 ,  20  are opposite and spaced apart from each other. The first surfaces  36  of the first  18  and second webs  20  and the first surface  32  of the first wall  12  define the channel  26 . Furthermore, each of the second  14  and third wall  16  has a first surface  40  that faces the first vertical direction and a second surface  42  that is opposite and spaced apart from the first surface  40  and faces the second vertical direction. 
     The floor support unit  10  also includes a first flange  28  and a second flange  30 . The first flange  28  extends from an intersection of the first wall  12  and the first web  18  in the plane of the first wall  12  in a first horizontal direction, and the second flange  30  extends from an intersection of the first wall  12  and the second web  20  in the plane of the first wall  12  in a second horizontal direction that is opposite of the first horizontal direction. The first  28  and second flanges  30  have second surfaces  44  that are coextensive with second surface  34  of the first wall  12 . 
     As shown in  FIGS. 3 and 4 , thermally insulating material  51  is disposed on at least a portion of the first surfaces  36  of the first  18  and second webs  20 , the first surface  32  of the first wall  12 , and the first surfaces  40  of the second  14  and third walls  16 . For example, the thermally insulating material includes a fiber reinforcing polymer material, sprayed foam insulation, and/or soy-based material. 
     Furthermore, in some implementations, the concrete of the floor support unit  10  may include pre-stressed tendons. 
       FIG. 5  illustrates a plurality of the floor support units  10  shown in  FIGS. 2-3  disposed horizontally adjacent each other on support beams. Each floor support unit  10  is elongated, and each floor support unit  10  has a first edge  46  and a second edge  48 . The first surfaces  32 ,  36 ,  40  and second surfaces  34 ,  38 ,  42  of each wall  12 ,  14 ,  16  and web  18 ,  20 , respectively, extend between the first edge and the second edge. 
       FIGS. 6A-6C  illustrates a plurality of support units  210   a,    210   b  disposed upon horizontal support beams, according to another implementation. The support units  210   a,    210   b  are similar to support unit  10  except as noted. As shown in this implementation, each flange  228 ,  230  defines a plurality of recessed portions  262  along a distal edge  264  of each flange  228 ,  230 . The distal edge  264  extends a first distance D 1  from the respective web  218 ,  220  from which the flange  228 ,  230  extends, and each recessed portion  262  has a second edge  266  that extends a second distance D 2  from the respective web  218 ,  220  from which the flange  228 ,  230  extends. The first distance D 1  is greater than the second distance D 2 . And, the distal edge  264  of the second flange  230  of the second elongated concrete floor support unit  210   b  abuts the distal edge  264  of the first flange  228  of the first elongated concrete floor support unit  210   a,  and the recessed portions  262  defined by each edge  264  align and define an opening through which supply air flows from the adjacent supply channel  258 . The second edge  266  may define a stepped portion  266   b  as shown in  FIG. 6C . The stepped portion  266   b  may receive a vent cover. For example, a horizontal portion of the stepped portion  266   b  may provide support for the vent cover, and a vertical portion of the stepped portion  266   b  prevents the vent cover from sliding horizontally. A depth of the vertical portion of the stepped portion  266   b  may be similar to a height of the vent cover so that an upper surface of the vent cover is flush with the second surfaces  244  of the respective flanges  228 ,  230 . 
     The implementation shown in  FIGS. 7A-7C  is similar to the implementation shown in  FIGS. 6A-6C  but each of the second wall  214 ′ and third wall  216 ′ defines a plurality of recessed portions  270 ′ along the distal edge  254 ′ of the second wall  214 ′ and the distal edge  256 ′ of the third wall  216 ′. The distal edges  254 ′,  256 ′ extend a first distance D 1 ′ from the web  218 ′,  220 ′ from which the second  214 ′ or third wall  216 ′ extends, respectively. And each recessed portion  270 ′ has a distal edge  272 ′ that extends a second distance D 2 ′ from the web  218 ′,  220 ′ from which the second  214 ′ or third wall  216 ′ extends. The first distance D 1 ′ is greater than the second distance D 2 ′, and the distal edge  254 ′ of the second wall  214 ′ of the first elongated concrete floor support unit  210   a ′ abuts the distal edge  256 ′ of the third wall  216 ′ of the second elongated concrete floor support unit  210   b ′. The recessed portions  270 ′ align and define openings  274 ′ through which supply air flows into the adjacent supply channel  258 ′ from the plenum  251 ′ disposed below the recessed portions  270 ′. 
     As shown in  FIGS. 8-11 , the first channels  226  on a particular level of a building are in fluid communication with one or more return trunks  250  for the particular level, and the return trunk(s)  250  for each level are in fluid communication with one or more return chases  252 , which return the air to heating, ventilation, and air conditioning (HVAC) system for conditioning. Similarly, the second channels  258  on a particular level of the building are in fluid communication with one or more supply trunks  253  for the particular level, and the supply trunk(s)  253  for each level are in fluid communication with one or more supply chases  260 , which supplies conditioned air to the supply trunks  253  from the HVAC system. 
     In the implementation shown in  FIGS. 8-9 , the supply trunks  253  are disposed adjacent the first edges  246  of the second channels  258 , and the return trunks  250  are disposed adjacent the first edges  246  of the first channels  226 . The supply chase(s)  260  and the return chase(s)  252  are also disposed adjacent an exterior side of the building adjacent the first edges  246  of the channels  226 ,  258 . 
     In other implementations, the supply and return trunks and the supply and return chases may be disposed adjacent other exterior sides of the building or extend through interior portions of the building (e.g., spaced inwardly from exterior sides). For example, in the implementation shown in  FIG. 10 , the return air trunks  150  and the supply air trunks  153  are disposed adjacent the distal edge  254  of the second wall  214  of a unit  210  that is disposed along an exterior side of the building, between the first edges  246  and second edges  248  of the units  210 . The return air chase  152  and supply air chase  160  are also disposed along that exterior side of the building. And, in the implementation shown in  FIG. 11 , the return and supply trunks and the return chase  252  and supply chase  260  extend through an interior portion of the building. 
     As shown in  FIGS. 8-11 , in some implementations, a pedestal access flooring layer  280  is disposed over the second surface  234  of the first wall  212  and the second surfaces  244  of the first  228  and second flanges  230 . The pedestal access flooring layer  280  includes a horizontal surface  282  supported by a plurality of adjustable pedestals  284  that are supported by the second surfaces  234 ,  244 . The height of each pedestal  284  is adjustable to provide a level, finished floor sub-surface for installation of the flooring material (e.g., carpet, hardwood, laminate, etc.) for the level of the building. The flooring layer  280  also defines the supply air plenum with the channels  258  below the flooring layer  280 . The flooring layer  280  further defines a plurality of vents  286  through which supply air flows into the level of the building. The vents  286  are adjustable to control the supply air flowing into the level of the building adjacent the vents  286 . Furthermore, baffles or other air directing structures may be disposed within the supply air plenum defined between the flooring layer and the second surfaces  234 ,  244  of the floor support units  210  to direct air flow through the supply air plenum. 
     In addition, a dropped ceiling may be disposed below the floor support units  210 . The dropped ceiling defines a plurality of vents through which return air flows into the return air plenum defined between the dropped ceiling and the first surfaces  240 ,  232 , and  236  and channel  226  of the floor support units  210 . 
       FIG. 12  illustrates another implementation of a floor support unit  110 . Each unit  110  includes a first wall  112 , a second wall  114 , a third wall  116 , a first web  118 , and a second web  120 , which are similar to the units  10 ,  210 ′,  210  described above in relation to  FIGS. 2-11 . However, the implementation shown in  FIG. 12  also includes a fourth wall  174  and a third web  178 . The third web  178  is spaced apart from the first web  118  and the second web  120 . In addition, the first  112  and fourth walls  174  are coplanar. The second  114  and third walls  116  lie in a plane that is parallel and spaced apart from the first  112  and fourth walls  174 . The first  118  and second webs  120  and the first wall  112  define a first channel  126  therebetween, and the third wall  116  and the second  120  and third webs  178  define a second channel  158  therebetween. The first channel  126  opens in a first vertical direction, and the second channel  158  opens in a second vertical direction that is opposite of the first vertical direction. 
     Similar to units  10 ,  210 ′,  210 , each unit  110  includes a first flange  180  and a second flange  182 . The first flange  180  extends from an intersection of the first wall  112  and the first web  118  in the plane of the first wall  112 , and the second flange  182  extends from an intersection of the first wall  112  and the second web  120  in the plane of the first wall  118 . However, unit  110  also includes a third flange  184  that extends from an intersection of the fourth wall  174  with the third web  178  in the plane of the fourth wall  174 . 
     The first  112 , second  114 , third  116 , and fourth walls  174  each include a first surface  132  and a second surface  134 . The first  132  and second surfaces  134  are opposite and spaced apart from each other, and the first surface  132  faces a first vertical direction and the second surface  134  faces a second vertical direction that is opposite from the first vertical direction. The first  118 , second  120 , and third webs  178  have a first surface  136  and a second surface  138 . The first  136  and second surfaces  138  of the webs  118 ,  120 ,  178  are opposite and spaced apart from each other. The first surfaces  136  of the first  118  and second webs  120  and first surface  132  of the first wall  112  define the first channel  126 , and the second surfaces  138  of the second  120  and third webs  178  and the second surface  134  of the third wall  116  define the second channel  158 . In some implementations, thermally insulating material  151  is disposed on at least a portion of the first surfaces  136  of the first  118 , second  120 , and third webs  178  and the first surfaces  132  of the first  112 , second  114 , third  116 , and fourth walls  174 . The unit  110  also includes a first edge and a second edge, and first  132  and second surfaces  134  of each wall  112 ,  114 ,  116 ,  174  and the first  136  and second surfaces  138  of each web  118 ,  120 ,  178  extend between the first edge and the second edge. 
       FIG. 13  shows another implementation of a floor support unit  410 . The unit  410  is similar to unit  110  but further incudes a fifth wall  486  and a fourth web  488 . The fifth wall  486  is coplanar with the second  414  and third walls  416 . The fourth web  488  is spaced apart from the first  418 , second  420 , and third webs  478 . The fourth web  488  extends between the fourth wall  474  and the fifth wall  486 . The third  478  and fourth webs  488  and the fourth wall  474  define a third channel  494  therebetween that opens in the first vertical direction. In addition, the unit  410  includes a fourth flange  496  that extends from an intersection of the fourth wall  474  with the fourth web  488  in the plane of the fourth wall  474 . 
     The first  412 , second  414 , third  416 , fourth  474 , and fifth walls  486  each include a first surface  432  and a second surface  434 . The first  432  and second surfaces  434  are opposite and spaced apart from each other, and the first surface  432  faces a first vertical direction and the second surface  434  faces a second vertical direction that is opposite from the first vertical direction. The first  418 , second  420 , third webs  478  and fourth webs  488  have a first surface  436  and a second surface  438 . The first  436  and second surfaces  438  of the webs  418 ,  420 ,  478 ,  488  are opposite and spaced apart from each other. The first surfaces  436  of the first  418  and second webs  420  and the first surface  432  of the first wall  412  define the first channel  426 , the second surfaces  438  of the second  420  and third webs  478  and the second surface  434  of the third wall  416  define the second channel  458 , and the first surfaces  436  of the third  478  and the fourth webs  488  and the first surface  432  of the fourth wall  474  define the third channel  494 . In some implementations, thermally insulating material  451  is disposed on at least a portion of the first surfaces  436  of the first  418 , second  420 , third  478 , and fourth webs  488  and the first surfaces  432  of the first  412 , second  414 , third  416 , fourth  474 , and fifth walls  486 . The unit  410  also includes a first edge and a second edge, and first  432  and second surfaces  434  of each wall  412 ,  414 ,  416 ,  474  and the first  436  and second surfaces  438  of each web  418 ,  420 ,  478  extend between the first edge and the second edge. 
     The terminology used herein is for the purpose of describing particular implementations only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The implementation was chosen and described to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various implementations with various modifications as are suited to the particular use contemplated.