Abstract:
A multi-paned fenestration unit in which the glass panes are manufactured directly into the support structure without first manufacturing an insulated glass unit. The support structure is designed to provide the structural support for the glass panes without a separate spacer.

Description:
RELATED APPLICATIONS 
     This application is a divisional of application Ser. No. 09/365,014, filed Aug. 2, 1999, now U.S. Pat. No. 6,463,706, which is a divisional of application Ser. No. 08/929,885, filed Sep. 15, 1997, now U.S. Pat. No. 6,055,783, which two applications are hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a fenestration unit which does not include an insulated glass unit (IGU). More specifically, the glass panes are placed directly into the sash without first being permanently fastened to each other by a spacer. This invention also includes a method for manufacturing a fenestration unit without the utilization of an IGU. 
     2. Description of the Prior Art 
     Early fenestration units, including windows and doors, only had a single pane of glass. Typically, the glass would be placed in the sash and then a glazing material would be applied to hold the glass into the sash. However, in more recent times, two or more panes of glass have been utilized in windows for better insulating value. A gap between any two glass panes creates further insulation. The prior art teaches the use of a separate spacer between the two glass panes to create such a gap and to structurally support the two panes of glass. 
       FIG. 1  illustrates a typical IGU  10  of the prior art. A first glass pane  11  is sealed to one end of spacer  12  with a sealant  14 , and a second glass pane  16  is sealed to the other end of spacer  12  with sealant  14 . The spacer  12  can be of many different shapes but often it is made with a jagged edge as shown in  FIG. 1  to reduce the conductance of heat through the spacer. This combination of two or more glass panes separated by a spacer is manufactured as a unit (IGU  10 ) and then later placed into the sash of the fenestration unit. 
       FIG. 2  illustrates the IGU  10  after it has been placed in the sash  17  of a fenestration unit. 
     The prior art fenestration units have a number of problems. Manufacturing involves two operations in which the first operation is manufacturing the IGU and the second operation is placing the IGU in the sash. This dual operation process incorporates significant cost into the fenestration unit. Additionally, this dual operation process typically involves shipping glass from the glass factory to the window manufacturer in the form of an IGU. Such shipping involves greater cost because the IGU&#39;s take up more space and they are easier to break than individual glass panes. Additionally, despite efforts to minimize thermal conductivity through the spacer  12 , there continues to be significant heat loss through the spacer  12 . 
     SUMMARY OF THE INVENTION 
     The invention has as its object manufacturing a fenestration unit in one operation wherein the glass panes are placed directly into the sash without the first operation of manufacturing an IGU. The sash (also referred to as the “support structure”) of the fenestration unit of this invention provides all of the structural support for the glass panes without the use of an IGU. In other words, the support of the glass panes is an integral part of the sash. 
     The invention provides a method of manufacturing a fenestration unit including the steps of constructing a support structure including a first receiving surface and a second receiving surface, placing a vapor barrier in contact with the first receiving surface and in contact with the second receiving surface, depositing a first primary sealant on a portion of the vapor barrier in contact with the first receiving surface, depositing a second primary sealant on a portion of the vapor barrier in contact with the second receiving surface, placing a first glass pane onto the first primary sealant on the first receiving surface, placing a second glass pane onto the second primary sealant on the second receiving surface, depositing a first secondary sealant between the first glass pane and the first receiving surface, where the first glass pane is structurally supported by the first receiving surface, and depositing a second secondary sealant between the second glass pane and the second receiving surface, where the second glass pane is structurally supported by the second receiving surface. 
     The invention also includes a fenestration unit comprising a first glass pane and a second glass pane. Both glass panes have an inside surface and an outside surface such that the inside surfaces face each other. The fenestration unit also includes a support structure having a first receiving surface and a second receiving surface. The first receiving surface of the sash receives the inside and outside surfaces of the first glass pane and the second receiving surface receives the inside and the outside surfaces of the second glass pane. The fenestration unit also includes a vapor barrier placed in contact with the first receiving surface and the second receiving surface. 
     The invention further provides a method of manufacturing a fenestration unit including the steps of constructing support structure members where each support structure member has a first receiving surface, a second receiving surface, a first end, and a second end. The method also includes the steps of depositing a first secondary sealant on the first receiving surfaces of each of the support structure members, depositing a second secondary sealant on the second receiving surfaces of each of the plurality of support structure members, positioning first and second glass panes on the first and second receiving surfaces, respectively, and fastening the ends of the support structure members to each other. This method forms a support structure around the first and second glass panes where the first receiving surface contacts the inside surface of the first glass pane and the second receiving surface contacts the inside surface of the second glass pane. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a prior art IGU. 
         FIG. 2  is a cross-sectional view of an IGU of the prior art inserted into a sash. 
         FIG. 3  is a frontal view of the fenestration unit of the invention including a partial cut-away. 
         FIG. 4  is a cross-sectional view of a first embodiment of the invention taken along the lines  4 — 4  of FIG.  3 . 
         FIG. 5  is a cross sectional view of the anti-outgassing strip of the first embodiment. 
         FIG. 6  is a cross-sectional view of the first embodiment of the invention and a window frame in a casement application. 
         FIG. 7  is a frontal view of the fenestration unit of a second embodiment of the invention including a partial cut-away. 
         FIG. 8  is a cross-sectional view of the second embodiment of the invention taken along a line  8 — 8  of FIG.  3 . 
         FIG. 9  is a cross-sectional view of the anti-outgassing strip of the second embodiment. 
         FIG. 10  is a cross-sectional exploded view of a third embodiment of the invention. 
         FIG. 11  is a frontal view of the fenestration unit of a fourth embodiment of the invention. 
         FIG. 12  is a cross-sectional view of a fourth embodiment of the invention taken along the line  12 — 12  of FIG.  11 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following description of the preferred embodiment, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. 
       FIG. 3  generally illustrates a fenestration unit  18  of the invention. The fenestration unit  18  includes a sash  19  which could also be a window or door frame. The use of the term “sash” is not intended to be limited to a strict sense of the word, but instead is defined as any structure that supports or holds a transparent material such as a glass pane. Therefore, the term “sash” will be used throughout this detailed description of the preferred embodiments, but it is understood to include a typical sash as well as any suitable support structure. The sash  19  includes four sash members  19   a ,  19   b ,  19   c  and  19   d  and is rectangular in shape. However, the sash members do not have to be lineal and the sash  19  could be any shape. Construction of the sash  19  involves constructing the sash members  19   a-d  and then fastening the sash members  19   a-d  together to create the sash  19 . The sash members  19   a-d  can be constructed by extrusion, wood milling or any other suitable manufacturing technique. The four sash members  19   a-d  can be fastened together in any manner known in the art. For example, depending on the type of material used for the sash  19 , the lineal sash members  19   a-d  could be connected together by an additional piece of connecting hardware, by vibratory welding, by temporary insertion of a heat plate between two adjacent sash members, or by any other method known in the art. 
     The sash  19  supports the first glass pane  20  and second glass pane  21 . The first glass pane  20  has an inner portion  22  and a border portion  23  (as seen through the cutaway portion of the sash  19 ). The border portion  23  is the portion around the periphery of the first glass pane  20 , i.e., the portion proximate to the sash  19 . In a preferred embodiment, the border portion  23  extends from the side  30  of the first glass pane  20  to about one inch from the side  30  in the direction of the interior portion  22  of the first glass pane  20 . The inner portion  22  is the portion of the first glass pane  20  which is not part of the border portion  23  and which is therefore a further distance from the sash  19 . The second glass pane  21  also has an inner portion  24  and a border portion  25  (also shown in the cut-away portion of the sash  19 ). The inner portion  24  and the border portion  25  are defined the same as above for the first glass pane  20 . The outside surface  26  of the first glass pane  20  faces the outdoors. The outside surface  32  of the second glass pane  21  faces the indoors. 
       FIG. 4  is a cross-sectional view of the first embodiment of the invention taken along the lines  4 — 4  of FIG.  3 . The first glass pane  20  includes an outside surface  26 , an inside surface  28  and a side  30 . The second glass pane  21  includes an outside surface  32 , an inside surface  34  and a side  36 . 
     The sash  19  may be made of any low-thermally conducting material. For example, the sash  19  could be hollow vinyl, hollow thermoplastic, thermoset pultrusion, milled solid wood or wood with a vinyl coating. Alternatively, the sash could be made of Fibrex™ material which is a wood fiber and polyvinyl chloride(PVC) composite patented by Andersen Corporation (See U.S. Pat. Nos. 5,406,768; 5,497,594; 5,441,801; 5,518,677; 5,486,553; 5,539,027). 
     The sash  19  includes a first receiving surface  38 , a second receiving surface  40  and an interior surface  42 . An anti-outgassing strip  44  has a first leg  47  at one end of the anti-outgassing strip  44  and a second leg  49  at the opposite end and an interior portion  53 . The interior portion  53  is located between the first leg  47  and the second leg  49 . The first leg  47  is attached to the first receiving surface  38 , the second leg  49  is attached to the second receiving surface  40  and the interior portion  53  of the anti-outgassing strip  44  is attached to the interior surface  42  of the sash  19 . The strip  44  is illustrated in  FIGS. 4 and 5 . The anti-outgassing strip  44  prevents gas particles in the sash  19  from outgassing into the space  45  between the first glass pane  20  and the second glass pane  21 , where these particles could interfere with the clarity of the fenestration unit  18 . The anti-outgassing strip  44  is a thin foil of metal but could be any material that prevents the gas particles from the sash  19  from passing through to the space  45 . For example, the anti-outgassing strip  44  may be made of stainless steel or aluminum. The anti-outgassing strip  44  is preferably made as thin as possible to reduce the conduction of heat through the strip  44  and yet thick enough to prevent outgassing. A stainless steel anti-outgassing strip  44  must be at least about 0.001″ (inches) thick in order to effectively reduce the movement of gas particles from the sash  19  to the space  45 . It is sometimes desired to use an anti-outgassing strip  44  that is between about 0.003″ (inches) and 0.005″ (inches) because such a thickness is easier to apply to the sash  19  without tearing or destroying the anti-outgassing strip  44 . It is also within the scope of this invention to apply a metallic spray to the interior surface  42 , the first receiving surface  38  and the second receiving surface  40 . This metallic spray would then be an anti-outgassing strip. The anti-outgassing strip  44  may be affixed to the sash  19  by an adhesive. Alternatively, the anti-outgassing strip  44  may include barbs  43 , as shown in  FIGS. 4 and 5 , which are pressed into the sash and which hold the anti-outgassing strip  44  to the sash  19 . It is also within the scope of this invention to merely place an anti-outgassing strip, without barbs and without an adhesive, on the interior surface  42 , the first receiving surface  38  and the second receiving surface  40 . Then the sealants and glass panes are placed as shown in FIG.  4  and described below to permanently hold the strip  44  in place. 
     The various sealants and their functions will now be described. The portion of the outside surface  26  of the border portion  23  of the first glass pane  20  that is not situated over the anti-outgassing strip  44  is attached to the first receiving surface  38  by a first secondary sealant  46 . The function of the first secondary sealant  46  is to provide an adhesive bond between the first glass pane  20  and the sash  19 . This adhesive bond is structural and prevents the first glass pane  20  from breaking away from the sash  19  in strong winds. The first secondary sealant  46  also prevents water from flowing along the outside surface  26  of the first glass pane  20  and into the space  45 . GE 2512 by General Electric Company is used as first secondary sealant  46  but other adhesives known in the art for attaching glass to the sash material may also be used. The portion of the outside surface  26  of the border portion  23  that is situated over the anti-outgassing strip  44  is attached to the anti-outgassing strip  44  by a first primary sealant  48 . The function of the first primary sealant  48  is to prevent migration of air or argon or any other insulating gas from the space  45  to the world outside the space  45 . The first primary sealant  48  could be any compound that prevents such migration such as, for example, polyisobutylene. The function of the sealant  48  is to prevent gas molecules from moving either into the space  45  or from leaving the space  45 . It is within the scope of this invention to use one adhesive/sealant in place of first secondary sealant  46  and first primary sealant  48 . The single adhesive would perform a dual function of structurally supporting the glass panes and sealing the space  45 . 
     The portion of the inside surface  34  of the border portion  25  of the second glass pane  21  that is not situated over the anti-outgassing strip  44  is attached to the second receiving surface  40  by a second secondary sealant  50  which is the same as and performs substantially the same function as the first secondary sealant  46 . The portion of the inside surface  32  of the border portion  25  of the second glass pane  21  that is situated over the anti-outgassing strip  44  is attached to the anti-outgassing strip  44  by a second primary sealant  52 . The second primary sealant  52  is the same as and performs substantially the same function as the first primary sealant  48 . 
     The depositing of the secondary sealants  46  and  50  and the primary sealants  48  and  52  may be accomplished by hand or using a machine. For example, a caulk gun could be used to deposit the various sealants. Robotic machines are also known in the art for depositing sealants in a specified pattern. 
     The first receiving surface  38  may include a lip  54  which is a portion that is raised from the remainder of the first receiving surface  38 . The lip  54  provides a space between the first glass pane  20  and the first receiving surface  38  such that the first secondary sealant  46  and the first primary sealant  48  are not squeezed out from between the first glass pane  20  and the first receiving surface  38 , thereby preventing a messy appearance along the interface between the sash  19  and the inner portion  22  of the outside surface  26  of the first glass pane  20 . 
     The sash shown in  FIG. 4  defines hollowed portions  56  which allow for a lighter weight sash  19  while retaining structural integrity and excellent insulating properties. However, the invention is not limited to this configuration. A sash defining more or fewer hollowed portions or no hollowed portions or differently shaped hollowed portions would also be within the scope of the invention. For example, if the sash  19  was made of milled wood, then it would not include the hollowed portions  56 . 
     The sash  19  includes a flange  58  adjacent to the side  36  of the second glass pane  21 . The flange  58  provides guidance to the proper placement of the second glass pane  21 . There is a gap  57  between the end  36  of the second glass pane  21  and the flange  58 . The purpose of the gap  57  is to allow the thermal expansion and contraction of the second glass pane  21  and to allow for permanent shrinkage of the sash  19 . 
     The second receiving surface  40  includes a stop  41  which is a portion of the sash which is raised. The stop  41  creates a gap between the second glass pane  21  and the second receiving surface  40  such that the second secondary sealant  50  and the second primary sealant  52  can remain in that gap. The stop  41  is located at the end of the anti-outgassing strip  44  and the stop  41  therefore forms the juncture between the second secondary sealant  50  and the second primary sealant  52   
     A desiccant material  60  may be attached to the anti-outgassing strip  44  by an adhesive. In the preferred embodiment, the dessicant  60  is an extruded, hot melt adhesive. The desiccant material  60  assists in the removal of moisture from the space  45 . The dessicant material  60  could alternatively be an adhesive type dessicant as described in U.S. Pat. Nos. 5,510,416; 5,509,984; and 5,503,884 owned by H. B. Fuller Licensing &amp; Financing, Inc. 
     The space  45  contains a thermally insulating gas. For example, air, Argon or Krypton or some combination of these three gases could be used. If air is used, then the manufacture of the fenestration unit  18  is simplified, because the dessicant  60  will remove moisture from the space  45  and no steps are necessary to remove the air and replace it with another gas. The description below discusses filling the space  45  with Argon as an example. The description also applies to other gases that may be used. 
     Filling the space  45  with Argon involves the following steps. First, the sash  19  is constructed with a hole or multiple holes that connect the space  45  to the outside air. An example hole is shown as hole  61 . A hose can be inserted into this hole and the air sucked out of the space  45  through the hose. Then Argon can be inserted into the space  45  through the same hose that passes through hole  61 . Alternatively, one or more holes  61  may be used to remove the air while Argon is inserted into the space  45  through one or more other holes also similar to hole  61 . Other methods of inserting Argon into the space  45  may be used. Once the space  45  is filled with Argon, then the plug  59 , shown in exploded view for clarity, is inserted in the hole  61  to seal the space  45 . There could be multiple holes  61  and plugs  59  per sash  19 . The plug  59  can be maintained in the hole  61  by any method including a friction fit or use of an adhesive. 
     The second secondary sealant  50  and the second primary sealant  52  may be visible through the second glass pane  21 . Therefore, it may be desirable to place a decorative trim piece along the border portion of the second glass pane  21  to hide the sealants from view. 
     The manufacture of the embodiment shown in  FIG. 4  will now be described. First, the sash  19  including the first receiving surface  38  and the second receiving surface  40  is constructed. The construction of the sash  19  includes joining the members  19   a-d . Next, the anti-outgassing strip is placed on the interior surface  42 , a portion of the first receiving surface  38  and a portion of the second receiving surface  40 . As discussed above, the anti-outgassing strip  44  may be attached to the sash  19  by barbs or by an adhesive. A dessicant as described above is then attached to the portion of the anti-outgassing strip  44  that is adjacent to the interior surface  42  of the sash  19 . The first secondary sealant  46  is deposited on the portion of the first receiving surface  38  that is not in contact with the anti-outgassing strip  44 . The second secondary sealant  50  is deposited on the portion of the second receiving surface  40  that is not in contact with the anti-outgassing strip  44 . Next, the first primary sealant  48  is deposited on the first leg  47  of the anti-outgassing strip  44 . The second primary sealant  52  is deposited on the second leg  49  of the anti-outgassing strip  44 . The next step is to place the border portion  23  of the outside surface  26  of the first glass pane  20  onto the first receiving surface  38  such that the border portion  23  of the outside surface  26  of the first glass pane  20  sits on the first secondary sealant  46  and the first primary sealant  48 . There should be a gap between the end  30  and the interior surface  42  of the sash  19 . Next, the border portion  25  of the inside surface  34  of the second glass pane  21  is placed on the second receiving surface  40  such that the border portion  25  of the inside surface  34  of the second glass pane  21  sits on the second secondary sealant  50  and the second primary sealant  52 . There should be a gap  57  between the end  36  and the flange  58 . Finally, the space  45  is filled with a thermally insulating gas through the hole  61  as described above. 
       FIG. 6  is similar to  FIG. 4  with the addition of a frame  62  that would be used for a casement window. The outside surface  26  of the first glass pane  20  faces the outdoors. The outside surface  32  of the second glass pane  21  faces the indoors. 
     In  FIG. 6 , the plug  59  is shown inserted into the sash assembly. A flexible bulbed weatherstop  63  is attached to the frame  62 . When the casement window is in a closed position as shown in  FIG. 6 , the flexible bulbed weatherstop  63  is in contact with the outside surface  32  of the second glass pane  21 . The sash  19  may be rotated outward away from the frame  62  as is typical of a casement window. In such a case, the outside surface  32  of the second glass pane  21  moves away from the flexible bulbed weatherstop  63 . The purpose of the flexible bulbed weatherstop  63  is to seal the window to prevent water from traveling between the frame  62  and the sash  19  when the window is in its closed position. 
     The manufacture of the structure shown in  FIG. 6  is the same as for the structure shown in  FIG. 4  with the additional step of placing the flexible bulbed weatherstop  63  into a groove  77  in the frame  62 . The weatherstop  63  is friction fit into the groove  77  so that the weatherstop  63  will not fall out of the groove  77 . Alternatively, an adhesive could be placed in the groove  77  to more securely fasten the weatherstop  63  in the groove. The groove  77  is located such that weatherstop  63  is adjacent the second glass pane  21  when the window is in the closed position as shown in FIG.  6 . 
     A frontal view of the second embodiment of the invention is shown in FIG.  7 . The sash  76  is made of four sash members  76   a-d . Each sash member has two ends, for example end  100  and end  102  of sash member  76   a . The first glass pane  64  has an inner portion  65  and a border portion  67 . The second glass pane  70  has an inner portion  71  and a border portion  73 . The inner and border portions in this embodiment are defined the same as with respect to the previous embodiment described above. 
       FIG. 8  is a cross-sectional view taken along the lines  8 — 8  in FIG.  7 . Again, in this embodiment as in the first embodiment discussed above, there is not a separate spacer between the two panes of glass and the glass panes are structurally supported entirely by the sash  76 . 
     The first glass pane  64  has an inside surface  66 , an outside surface  68  and a side  69 . The second glass pane  70  has an outside surface  72 , an inside surface  74  and a side  75 . The inside surface  66  of the first glass pane  64  faces the inside surface  74  of the second glass pane  70 . 
     The sash  76  includes a channel having a U-shaped cross-section and a plurality of receiving surfaces  78  that receive the border portion  67  of the inside surface  66  of the first glass pane  64 , and the border portion  67  of the outside surface  68  of the first glass pane  64 . The channel&#39;s receiving surface  78  may also abut against the side  69  of the first glass pane  64 . 
     Moreover, the sash  76  includes a second channel having receiving surfaces  80  that receive the border portion  73  of the inside surface  74  of the second glass pane  70 , and the border portion  73  of the outside surface  72  of the second glass pane  70 . The second channel&#39;s receiving surface  80  may also abut against the side  75  of the second glass pane  70 . 
     The sash  76  also includes an interior surface  81  which extends between the first and second channels. In this embodiment, the anti-outgassing strip  82  has a U-shaped cross-section, with an interior portion extending between a first leg  97  and a second leg  98 . The central portion of the anti-outgassing strip  82  extends across the sash&#39;s interior surface  81 . Each leg of the strip  82  abuts against the first receiving surface  78  into the second receiving surface  80 . The anti-outgassing strip  82  is made of the same material and performs the same function as the anti-outgassing strip  44  of the first embodiment shown in FIG.  4 . The anti-outgassing strip  82  may be attached to the sash  76  by an adhesive or by barbs  79 .  FIG. 9  shows a cross section of the anti-outgassing strip  82  including barbs  79  which are inserted into the sash  76 . 
     The first receiving surface  78  is attached to the border portion  67  of the outside surface  68  of the first glass pane  64  by a adhesive  84 . The second receiving surface  80  is attached to the border portion  73  of the outside surface  72  of the second glass pane  70  by a adhesive  85 . The adhesives  84  and  85  are the same and perform the same function as the adhesives  46  and  50  of the first embodiment. 
     The anti-outgassing strip  82  is attached to the border portion  67  of the inside surface  66  of the first glass pane  62  by a sealant  86 . The anti-outgassing strip  82  is attached to the border portion  73  of the inside surface  74  of the second glass pane  70  by a sealant  88 . The sealants  86  and  88  are the same and perform the same function as the sealants  48  and  52  of the first embodiment. 
     The receiving surfaces  78  and  80  may contain stops  89  and  91  respectively, for allowing some space for the sealant  86  (i.e. first primary sealant  86 ) and the sealant  88  (i.e. second primary sealant  88 ) between the inside surfaces  66  and  74  and the receiving surfaces  78  and  80 , respectively. The stops  89  and  91  are raised portions that rise above the remainder of the receiving surfaces. The purpose of the stops  89  and  91  is to prevent the first and second primary sealants  86  and  88  from squeezing out from between the receiving surfaces  78  and  80  and the first and second glass panes  64  and  70  respectively. The receiving surfaces  78  and  80  may be designed without the stops  89  and  91  but then some squeeze out of the primary sealants may occur. 
     The portions of the receiving surfaces  78  and  80  adjacent to the outside surfaces  68  and  72  of the first and second glass panes  64  and  72  respectively, are angled away from the glass so that the distance from the glass to the sash becomes less, nearer to the edges  69  and  75 . The purpose of this angle in the receiving surfaces of the sash is to facilitate the deposition of a first secondary sealant  84  and a second secondary sealant  85  between the sash and the first and second glass panes  64  and  70  respectively. It should be noted however that the present invention is not limited to the described receiving surfaces. The receiving surfaces described above are a preferred embodiment. 
     In a preferred embodiment the first receiving surface  78  also includes a raised member  93  for applying pressure to the outside surface  68  of the first glass pane  64  to hold the inside surface  66  of the first glass pane  64  in contact with the stop  89 . Additionally the second receiving surface  80  includes a raised member  95  for applying pressure to the outside surface  72  of the second glass pane  70  to hold the inside surface  74  in contact with the stop  91 . 
     The raised members  93  and  95  can be any shape which applies the appropriate pressure and should be flexible enough to allow the first secondary sealant  84  and second secondary sealant  85  to pass between it and the adjacent glass pane when such sealants are deposited. In a preferred embodiment the raised member  93  and  95  are rigid PVC. 
       FIG. 8  also shows the desiccant material  90  attached to the anti-outgassing strip  82  along the interior surface  81  of the sash  76 . The purpose and design of the desiccant material  90  is the same as the purpose and design of the desiccant material  60  in the first embodiment of the invention. A dessicant adhesive as described above with respect to the first embodiment may also be used for this embodiment. 
     Again, with this embodiment as in the first embodiment, either air or Argon or a combination of both may be used to fill the space  92  between the first glass pane  64  and the second glass pane  70 . If Argon is used, then a hole  94  may be used to insert a hose for removing air and inserting Argon into the space  92 . Once the space  92  is filled or partially filled with Argon, then it may be blocked with a plug  96  which is shown in exploded view for clarity. 
     The manufacture of the second embodiment involves the following steps. First, the sash members  76   a-d  are constructed. The sash members can be made from an extruded vinyl or composite or other material, or they can be milled from a wood. Second, the anti-outgassing strip  82  is placed on the interior surface  81  of the sash members  76   a-d . The placement of the anti-outgassing strip  82  can either utilize an adhesive or barbs or both. In a preferred embodiment the anti-outgassing strip  82  has a first leg  97 , a second leg  98  and an interior portion  99 , wherein the interior portion  99  is between the first leg  97  and the second leg  98 . The first leg  97  is adjacent to a portion of the first receiving surface  78 , the second leg is adjacent to a portion of the second receiving surface  80  and the interior surface  99  of the anti-outgassing strip  82  is adjacent to the interior surface  81  of the sash  76 . 
     The first secondary sealant  84  is deposited on the portion of the first receiving surface that is not in contact with the anti-outgassing strip  82 . The first primary sealant  86  is deposited on the first leg  97  of the anti-outgassing strip  82 . The second secondary sealant  85  is deposited on the portion of the second receiving surface  80  that is not in contact with the anti-outgassing strip  82 . The second primary sealant  88  is deposited on the second leg  98  of the anti-outgassing strip  82 . The depositions can be done manually using a caulk gun or automatically with a machine or robot. Then the first glass pane  64  is placed on a platform or support and the second glass pane  70  is suspended parallel and above the first glass pane  64  with the space between the two glass panes being similar or equal to the space  92  desired in the ultimate fenestration unit. For example, suction cups could be applied to the outside surface  72  of the second glass pane  70  to suspend the second glass pane  70  over the first glass pane  64 . The sash members  76   a-d  are then placed around the first and second glass panes  64 ,  70  such that the first receiving surface  78  receives the border portion of the first glass pane  64  and the second receiving surface  80  receives the border portion of the second glass pane  70 . The ends of the sash members  76   a-d  are then fastened together using heat plates or vibratory welding or any other means of fastening the ends of sash members  76   a-d  together to form a sash  76 . The resulting sash  76  as shown is rectangular in shape, but it could be any shape. 
     A third embodiment of the invention is shown in exploded view in FIG.  10 . This embodiment is similar to the second embodiment shown in  FIG. 8  with the difference being that the sash in the third embodiment is three sash sections  110 ,  112  and  114 . When the parts are assembled together the first receiving surface  120  of the first sash section  110  is adjacent to the outside surface  68  and a portion of the end  69 . The second receiving surface  122  of the second sash section  112  is adjacent to the inside surface  66  and a portion of the end  69 . The third receiving surface  124  located on the second sash section  112  is adjacent to the inside surface  74  and a portion of the end  75 . The fourth receiving surface  126  of the third sash section  114  is adjacent to a portion of the end  75  and the outside surface  72 . 
     If the sash is rectangular, then there are four first sash sections, four second sash sections and four third sash sections. The advantage of using first, second and third sash sections  110 ,  112  and  114  is that manufacturing is accomplished in a bed formation in which one layer is placed on top of the other. The manufacturing steps are described below. 
     First, the three sash sections  110 ,  112  and  114  are assembled. For a rectangular window, this assembly comprises connecting the four first sash section lineals to each other at the corners to form a rectangular frame. The connection can be by any of the methods described above including hot plate welding, vibratory welding or the use of a mechanical fastener. This rectangular frame is referred to in whole as the first sash section  110 . The same assembly process is performed to assemble the second and third sash sections  112  and  114 . Next, the anti-outgassing strip  82  is placed on the interior surface  81 , on the second receiving surface  122  and on the third receiving surface  124 . Then the dessicant material  90  is placed on the interior surface  81  of the second sash section  112 . 
     A first secondary sealant  84  is deposited on the first receiving surface  120 . Alternatively, the first secondary sealant  84  can be deposited on the border portion  67  of the outside surface  68  of the first glass pane  64 . Then the border portion  67  of the outside surface  68  of the first glass pane  64  is placed on the first receiving surface  120 . A first primary sealant  86  is deposited on the portion of the anti-outgassing strip  82  that is adjacent to the second receiving surface  122 . Alternatively, the first primary sealant  86  can be deposited on the border portion  73  of the inside surface  66  of the first glass pane  64 . Next, the second sash section  112  is lowered onto the first sash section such that the portion of the anti-outgassing strip  82  that is adjacent to the second receiving surface  122  is placed on the border portion  73  of the inside surface  66  of the first glass pane  64 . A second primary sealant  88  is deposited on the portion of the anti-outgassing strip  82  that is adjacent to the third receiving surface  124 . Alternatively, the second primary sealant  88  may be deposited on the border portion  73  of the inside surface  74  of the second glass pane  70 . Then the border portion  73  of the inside surface  74  is placed on the portion of the anti-outgassing strip  82  adjacent to the third receiving surface  124 . A second secondary sealant  85  is deposited on the fourth receiving surface  126 . Alternatively, the second secondary sealant  85  may be deposited on the border portion  73  of the outside surface  72 . The fourth receiving surface  126  is then placed on the border portion  73  of the outside surface  72 . 
     The three sash sections  110 ,  112  and  114  may be connected together by any method including by an adhesive such as silicone sealant or by use of a fastener.  FIG. 10  shows a screw  130  which fits into the hole  132  which extends through the third and second sash sections  114  and  112  and partially into the first sash section  110 . A number of such screws  130  would be inserted into a corresponding number of holes  132  around the entire sash to connect all three sash sections together. The end result is that the three sash sections  110 ,  112  and  114  are connected to form one sash which supports the glass panes. 
     A fourth embodiment of the invention is shown in  FIGS. 11-12 .  FIG. 11  generally illustrates a fenestration unit  170  of the invention. The fenestration unit  170  includes a sash  200  which could also be a window or door frame. The sash  200  includes four sash members  200   a ,  200   b ,  200   c  and  200   d  and is rectangular in shape. However, the sash members do not have to be lineal and the sash  200  could be any shape. Construction of the sash  200  involves constructing the sash members  200   a-d  and then fastening the sash members  200   a-d  together to create the sash  200 . The sash members  200   a-d  can be constructed by extrusion, wood milling or any other suitable manufacturing technique. The four sash members  200   a-d  can be fastened together in any manner known in the art. For example, depending on the type of material used for the sash  200 , the lineal sash members  200   a-d  could be connected together by an additional piece of connecting hardware, by vibratory welding, by temporary insertion of a heat plate between two adjacent sash members, or by any other method known in the art. 
     The sash  200  supports the first glass pane  222  and second glass pane  230  creating a space  181  between the glass panes. The first glass pane  222  has an inner portion  172  and a border portion  174 . The inner portion  172  and the border portion  174  are defined the same as for the prior embodiments. In a preferred embodiment, the border portion  174  (seen through the cut-away of the upper glazing bead  175 ) extends from the side  176  of the first glass pane  222  to about one inch from the side  176  in the direction of the inner portion  172  of the first glass pane  222 . The second glass pane  230  also has an inner portion  178  and a border portion  180 . The inner portion  178  and the border portion  180  are defined the same as above for the first glass pane  222 . 
       FIG. 12  shows a cross sectional view of the fourth embodiment of the invention. The sash  200  is the same material and is constructed in the same manner as the sash  19  described above. The sash  200  has a hollowed portion  182 . This hollowed portion is to reduce the weight of the fenestration unit  170 . However, the invention is not limited to the particular shape of the hollowed portion  182  shown in FIG.  12  and in fact it is within the scope of this invention to use a solid sash  200  without a hollow portion  182 . The sash includes a first receiving surface  202  which is generally flat but including a stop  204  which is portion of the first receiving surface that is raised above the generally flat portion of the first receiving surface  202 . The sash  200  also includes a second receiving surface  206  which is generally flat but includes a stop  208 . The sash  200  also includes an interior surface  210  which is located between the first receiving surface  202  and the second receiving surface  206 . 
     An anti-outgassing strip  212  which is the same as the anti-outgassing strip  82  is located in contact with the interior surface  210 . The anti-outgassing strip includes barbs  213  for attaching to the sash  200 . However, as described above, the invention is not limited to the use of barbs for attachment to the sash  200 . The anti-outgassing strip  212  includes a first leg  214 , a second leg  216  and an interior portion  218 . The first leg  214  is in contact with a portion of the first receiving surface  202  as shown in FIG.  12 . The second leg  216  is in contact with a portion of the second receiving surface  206  also as shown in FIG.  12 . The first leg  214  and the second leg  216  extend up to the respective stops  204  and  208 . The interior portion  218  is in contact with the interior surface  210  of the sash  200 . The purpose of this anti-outgassing strip  212  is the same as for the first two embodiments of this invention. 
     A dessicant material  184  is located on the interior surface  218  of the anti-outgassing strip  212 . A plug  186  is shown exploded out from the hole  188 . The plug  186  fits into the hole  188  and serves the same purpose as the plugs and holes in the earlier described embodiments. 
     A first secondary sealant  220  is located between the inside surface  221  of the first glass pane  222  and the first receiving surface  202 . The first secondary sealant  220  is the same as the first secondary sealant discussed above with respect to the first two embodiments of this invention. A first primary sealant  224  is located between the first leg  214  of the anti-outgassing strip  212  and the first glass pane  222 . The first primary sealant  224  is the same as the first primary sealants in the first two embodiments of this invention. 
     A second secondary sealant  226  is located between the inside surface  228  of the second glass pane  230  and the second receiving surface  206 . The second secondary sealant  226  is the same as the first secondary sealant  220 . A second primary sealant  232  is located between the second leg  216  of the anti-outgassing strip  212  and the second glass pane  230 . The second primary sealant  232  is the same as the first primary sealant  224 . The stops  204  and  208  serve the same function as the stop  41  in the first embodiment. 
     The upper glazing bead  175  is an aesthetic piece which hides the second secondary sealant  226  and the second primary sealant  232  from view of an observer. Likewise, the lower glazing bead  177  hides the first secondary sealant  220  and the first primary sealant  224  from view of an observer. The tips  190  and  192  of the glazing beads  177  and  175  are flexible so that the tips can be pressed tightly against the outside surfaces of the glass panes. The glazing beads  177  and  175  may also apply some pressure to the outside surfaces of the first and second glass panes  222  and  230  respectively. This pressure may assist in holding the glass panes in place while the sealants  220 ,  224 ,  226  and  232  are curing. 
     The manufacturing steps in this fourth embodiment are the same as for the first embodiment with one exception. The first glass pane is positioned on the sash  200  differently in that the border portion  174  of the inside surface  221  of the first glass pane  222  is placed on the first receiving surface  202 . The first glass pane  222  may be placed on a support structure to hold the first glass pane in contact with the sealants and the first receiving surface. Such a support could be a table or other structure. Alternatively, a fast curing sealant or hot melt can be used as the first secondary sealant  220  to allow the first glass pane  222  to be quickly adhered to the first receiving surface  202 . 
     The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.