Abstract:
A structure comprises at least one outer wall having an internal wall section and an outer wall section with an air flow passage therebetween. Air is passed through the air flow passage to inhibit moisture accumulation and/or mold growth. A controller may determines a parameter relating to condition of the air in the air passage and in response thereto control the air flow through the air passage. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a continuation-in-part of and takes priority from U.S. patent application Ser. No. 10/006,635, filed on Nov. 8, 2001, which is fully incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to structures having an outer wall system, the construction of which provides for flow of air between an internal wall section and an external wall section for inhibiting moisture accumulation and mold growth on the internal wall section.  
         [0004]     2. Description of the Related Art  
         [0005]     In today&#39;s construction industry, numerous residential structures, along with a significant number of commercial structures such as, for example, apartment buildings, motels, restaurants, and strip shopping centers, have their exterior surfaces finished with a synthetic stucco-type coating applied over a foam insulation board. Such exterior finishes are generically referred to as Exterior Insulation and Finish Systems, and will be referred to hereinafter as EIFS.  
         [0006]     While such EIFS constructions have proven to be satisfactory regarding their relative ease of installation, the insulating properties and the ability to receive a variety of aesthetically-pleasing finishes, such constructions are vulnerable to moisture accumulation behind their exterior wall coverings. As used herein, the term “moisture” refers to both liquid and airborne forms of water. Such moisture may be the result of condensation or high humidity, but may also be the result of rain or wind-driven water, that may enter behind the exterior wall covering at any point where the exterior surface of the coating is penetrated. Such moisture accumulation may be the result of poor workmanship or design, deterioration of flashing or sealants over time, lesser quality doors or windows, or any other penetration or compromise of the exterior finish.  
         [0007]     When such water penetration, high humidity or condensation occurs, absent effective, reliable methods for eliminating or reducing the moisture accumulation behind the EIFS or other exterior constructions, the moisture can remain trapped long enough before evaporating to damage or rot any moisture-sensitive elements to which the insulation is attached, typically wood framing, oriented-strand board, plywood, or gypsum sheathing. In addition, the moist environment is a breeding ground for wood consuming insects and health hazards such as various varieties of molds. This problem is exacerbated in hot and humid environments.  
         [0008]     Attempts have been made to prevent entry of moisture into the building wall interior by sealing or caulking entry points in and around wall components as the primary defense against moisture intrusion, or by installing flashing around the wall components to divert the moisture. These attempts have not been completely successful. Sealants are difficult to properly install and also tend to deteriorate and separate from the wall components or wall due to changes in climatic conditions, building movement, the surface type and/or chemical reactions. Flashing is also difficult to install and may tend to hold the moisture against the wall components, accelerating the decay.  
         [0009]     The use of sealants and flashings is also limited to the attempted minimization of moisture collection in building walls in new construction, and the further collection in existing structures. These materials are of little value in addressing the problem of moisture that has already entered a building wall interior. The problem is further compounded by the prevention of evaporation of the moisture already in the wall interior.  
         [0010]     The problems of moisture penetration and accumulation have prevented the full use of new building cladding materials and may have resulted in many buildings with rotting framing structures, requiring extensive and expensive retrofitting. Thus, there is a need for a system and method to prevent or inhibit moisture from accumulating in the walls a buildings and for the removal of moisture that has already collected within the walls.  
       SUMMARY OF THE DISCLOSURE  
       [0011]     In one aspect, a structure is disclosed that includes an air supply system that supplies air under pressure; and an inner space enclosed by at least one wall, the at least one wall having an inner section and an outer section, the inner and outer sections defining an air flow passage that is configured to receive at least a portion of the air under pressure at a first opening and to discharge at least a portion of such received air to an outside environment via a second opening.  
         [0012]     In another aspect, a structure is disclosed, wherein air is supplied under pressure to an air flow passage between panels of a window to inhibit moisture build-up therein.  
         [0013]     In another aspect, the disclosure provides a method of inhibiting moisture in an outer wall of a structure that includes an air flow passage having a first opening to receive air and a second opening to discharge the air, wherein the method comprises supplying air under pressure at the first opening and allowing at least a portion of the air supplied under pressure to the air flow passage to discharge to an outside environment from the second opening to inhibit moisture in the outer wall.  
         [0014]     In another aspect, the disclosure contemplates a structure with an outer wall having an internal wall section and an external wall section with a flow passage in between. A circulation system passes air through the flow passage inhibiting moisture accumulation and mold growth.  
         [0015]     In one embodiment, a structure system comprises at least one outer wall having an internal wall section and an external wall section, where the external wall section is located such that there is an air flow passage between the internal wall section and the external wall section. A circulation system circulates air through the air flow passage to inhibit moisture on the internal wall section.  
         [0016]     In another embodiment, an essentially enclosed structure system comprises at least one outer wall having an internal wall section and an external wall section, where the external wall section is located such that there is an air flow passage between the internal wall section and the external wall section. A circulation system circulates air through the air flow passage to inhibit moisture on the internal wall section.  
         [0017]     In another embodiment, an essentially enclosed structure system comprises at least one outer wall having an internal wall section and an external wall section, where the external wall section is located such that there is an air flow passage between the internal wall section and the external wall section. A circulation system circulates air through the air flow passage to inhibit moisture on the internal wall section. At least one sensor generates a signal indicative of moisture and generates a signal in response thereto. A controller receives the signal from the at least one sensor and controls the circulation system to provide a predetermined relative humidity of the air flow in the air flow passage.  
         [0018]     In one embodiment, a method is described for inhibiting moisture accumulation in an outer wall of a structure, comprising: providing an outer wall with an internal wall section and an external wall section with an air flow passage therebetween; and supplying air into the flow passage by an air circulation system to inhibit moisture accumulation on the internal wall section.  
         [0019]     Examples of the more important features of the invention thus have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     For detailed understanding of the present disclosure, references should be made to the following detailed description of the embodiments, taken in conjunction with the accompanying drawings, in which like elements have generally been given like numerals, wherein:  
         [0021]      FIG. 1  is a perspective drawing of a structure according to one preferred embodiment of the present invention;  
         [0022]      FIG. 2  is a schematic of a structure of a circulation system according to one embodiment of the present invention;  
         [0023]      FIG. 3  is a block diagram of another circulation system according to one embodiment of the present invention;  
         [0024]      FIG. 4  is a schematic of a functional block diagram for use in the structures according to one embodiment of the present invention; and  
         [0025]      FIG. 5  is a schematic diagram showing a circulation system for a structure according to another embodiment of the invention. 
     
    
     DESCRIPTION OF EMBODIMENTS  
       [0026]     Referring to  FIG. 1  and  FIGS. 2A and 2B  (collectively referred to as  FIG. 2 ),  FIG. 1  shows a perspective view and  FIG. 2  shows a sectional view of an outer wall  25  of a structure according to an exemplary embodiment of the present invention. The structure  30  comprises a foundation slab  20  having a dual section outer wall  25  attached thereto. In some structures, a subspace  102 , such as a basement or a crawl space may also be present. The dual section outer wall  25  has an un-insulated internal wall section  26  and an insulated external wall section  27  displaced a distance away from internal wall section  26  such that an air flow passage  17  is established between them. Conditioned air  16  is forced out through the air passage  17  by the air circulation system  45  shown in  FIG. 2  and described below, thereby inhibiting the accumulation of moisture and mold on the internal wall section  26 .  
         [0027]     The external wall section  27  is constructed with an exterior insulation and finish system, commonly referred to as EIFS, which comprises a weather resistant outer surface  2 , typically of synthetic stucco, attached to a thermal insulating layer  21 . Alternatively, any suitable weather resistant material may be used, including, but not limited to, brick tile, stone tile, wood siding, pressed board siding, and cementicious siding. The thermal insulating layer  21  is typically formed from an expanded polystyrene foam, but may alternatively be made from a polycyanurate or polyurethane foam or from any other suitable insulation material. The insulating layer  21  is, in turn, attached to a sheathing layer  4 , typically a cementicious material known in the art. The external wall section  27  is attached to furring strips  6  which are in turn attached to the internal wall section  26  using attachment techniques known in the art. The furring strips  6  serve to establish the size of the flow passage  17  and to secure the outer wall section  27  to the inner wall section  26 . Furring strips  6  may also be positioned to direct the flow of air  16  in the passage  17 . The furring strips can be any suitable furring strips, including but not limited to a “Z” shaped galvanized steel strip. Drain channel  18  is located near the bottom of passage  17  and is sloped to provide a drainage for any condensation or water which may need to be expelled from passage  17 . Channel  18  may be solid and thereby used to direct the air flow  16  exiting from the passage  17  at an opening  19 . Alternatively, channel  18  may have multiple holes allowing moisture and air flow  16  to exit at the base of the exterior wall  25 .  
         [0028]     The inner wall section  26  comprises a suitable liquid barrier  8  attached to an external sheathing  10 , which may be a plywood or oriented stranding board (OSB). The liquid barrier  8  inhibits or minimizes the passage of liquid water but allows for the passage of gases and water vapor and is well known in the art. The external sheathing  10  is attached to and supported by the framing studs  12 . Any suitable framing stud material can be used including wood and metal materials. An interior sheathing  14  such as paneling, drywall board, or other suitable interior surface is attached to the interior side of the framing studs  12 . In one aspect, the inner wall section  26 , contrary to common construction, may have minimal or no insulation in its internal cavities. However, the internal wall section may include insulation normally contained in residential or commercial structures. The flow of appropriately conditioned air  16  through the flow passage  17  bordered by external sheathing  10  provides an air temperature at the external sheathing essentially the same as the air temperature inside the structure  30  thereby inhibiting condensation on the liquid barrier  8  or the sheathing  10 .  
         [0029]     Still referring to  FIGS. 1 and 2 , wall  25  may include one or more windows, such as window  120 . The window  120 , in one aspect, may include an inside pane  120   a  and an outside pane  120   b  with an air passage  120   c  therebetween. The window may further include an air inlet opening  116  and an air outlet opening  119 . In one aspect, air under pressure from the air system  45  ( FIG. 2 ) or from the inner space  50  may be passed into the spacing  120   c  at the opening  116  and discharged at the opening  119  so as to inhibit or eliminate condensation in the space  120   c.    
         [0030]     As shown in  FIG. 2 , a circulation system  45  (also referred to as the air supply system) is shown located in an attic space  36  of structure  30 . The attic  36  is bounded by roof  22  and ceiling  29 . Roof  22  is connected to and essentially sealed with external wall section  27  by flashing  28  which extends around the periphery of structure  30 . Conditioned air  16  from the circulation system  45  is forced through duct  33  into the interior  50  of structure  30 . The air  16  exits the interior space  50  through a plurality of ceiling vents  34  which exhaust into the attic space  36 . The attic space acts as a plenum for circulation system  45 . Air enters the circulation system  45  through inlet damper  43  in attic  36  and outside makeup air  44  enters through makeup damper  46  and the combined intake air flows through blower  42  and into heating and cooling elements in conditioner  40 , through duct  32  into humidifier  38  for maintaining a predetermined relative humidity. The heater elements (not shown), in conditioner  40  may be electric or gas type elements common in the art, or any other suitable heating elements. The cooling system (not shown) in conditioner  40  may be a conventional compressor/condenser type system. Alternatively, a heat pump system may be used for heating and cooling the air, as may other suitable systems. Guidelines for selecting the predetermined relative humidity are available in published documents of The American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE), Standard 62-1999, Ventilation for Acceptable IndoorAir Quality, which indicates that the relative humidity should be maintained below about 70% to inhibit fungal contamination including, but not limited to, molds and mildew. The actual relative humidity and air flow requirements will be structure-specific and are determined using procedures and standards known in the art.  
         [0031]     The conditioned air flows through duct  33  and into interior space  50  and as previously described, exhausts through vents  34  into attic  36 . The addition of the outside makeup air  44  to the air volume existing in the essentially sealed structure creates a suitable positive pressure in the structure  30  and attic  36  relative to the outside environment, and causes conditioned air to flow  16  through the air flow passage  17  in the outer wall  25 . In one aspect, the blower  42  may operate continuously or substantially continuously forcing an essentially continuous flow of conditioned air  16  through the passage  17 , thereby inhibiting the buildup of moisture and mold on the inner wall section  26 . Alternatively, the air may be passed through the air passage selectively in response to one or more sensor inputs.  
         [0032]     Dampers  43  and  46  may be manually set to provide the appropriate flows. Alternatively, the dampers  43  and  46  may have actuators (not shown) which may be controlled remotely. Additionally, baffles  112   a  and/or  112   b  may be utilized to control the flow of outside air into the air passage  17 . The baffles may be mechanically controlled, such as by a spring action or electrically controlled. Any other suitable device may also be used to control the outside air.  
         [0033]     In one exemplary embodiment, such as shown in  FIG. 3 , temperature and relative humidity sensors  62  and  63  are disposed in passage  17  to measure the temperature and relative humidity of conditioned air flow  16 . Signals from the sensors are received by a control system  60 , which may contain sensor interface circuits, a processor, and output control circuits for actuating devices in the circulation system  45 . As shown in  FIG. 3 , control system  60  receives signals from sensors  62  and  63  and acts according to programmed instructions to actuate makeup air damper  46 , intake damper  43 , blower  42 , conditioner  40 , and humidity controller  38  to maintain a predetermined temperature and relative humidity in conditioned air flow  16 .  
         [0034]     In another exemplary embodiment, such as  FIG. 4 , conditioned air is split from duct  33  and travels in header  52  around the periphery of the attic space  36 . Multiple discharge ducts  54  direct conditioned air  16  from the header towards the opening of passage  17 . The air flow is controlled by multiple dampers  56  on multiple discharge ducts  54 . The dampers  56  may be manually set or, alternatively, may be fitted with actuators (not shown) which may be remotely controlled by control system  60 .  
         [0035]     In another embodiment, a plurality of blowers (not shown) may be mounted so as to intake the conditioned attic air and discharge the air directly into the passage  17  at a plurality of predetermined locations around the perimeter of the structure. The passage of the discharged air passing between the furring strips  6  act to create a venturi effect to induce flow from between adjacent furring strips  6 .  
         [0036]     It will be appreciated by those skilled in the art, that the circulation system  45  may be wholly located external to the structure  30  with air flow to and from the structure  30  through suitable conduit or ducting (not shown). Alternatively, the circulation system  45  may be partially located in the structure  30  and partially located external to the structure  30  as is common in home systems. It is also to be understood that local environmental conditions and local building codes will, to some extent, dictate the individual components used.  
         [0037]      FIG. 5  shows a schematic diagram of an air supply system  200  according to one embodiment that may be utilized with a structure  201 , which may be any type of structure including a multistory building. The structure  201  is shown to include an inner space  202  that has a first outer wall  204   a  that includes an outer section  206   a  and an inner section  208   a  and an air passage  210   a  between these inner and outer sections. Also shown is a second outer wall  204   b  that has an air passage  210   b  that is bounded by the inner and outer sections  206   b  and  208   b  of the wall  204   b . The structures of the walls  204   a  and  204   b  may be the same, similar or different from the ones described in reference to  FIGS. 1-4 . Also, the air supply system  220  may be the same or similar to the systems described in reference to  FIGS. 1-4  or any other suitable system. The structure  201  also is shown to include a secondary enclosed space  102  adjacent to and in air flow communication with the inner space  202 . The structure  201  may also include any number of additional enclosed spaces in air communication with one or more such spaces and may lie above, below, adjacent or spaced from the inner space  202 . The secondary space  102  may also be a subfloor or subspace, such as a basement or crawl space.  
         [0038]     In one aspect, the air supply system  220  may supply air  211  under pressure to the inner space  202 . All or a portion of the air from the inner space  202  may then be passed to a secondary enclosed space, such as space  102 . In one aspect, the air from the space  102  may be passed to one or more of the air passages, such as the passage  210   b  via an opening  266  and then to the outside environment via an opening  268 , as shown by arrows  267 . A baffle  212   b  or another suitable device may be provided to inhibit outside air from entering the air flow passage  210   b . Alternatively or in addition to the above, the air from the secondary space  102  may pass directly to the outside environment via an air outlet  264  or to the air system  220  via a suitable conduit or return air flow path, shown generally by arrow  265 . In another aspect, air  233  from the inner space  202  and/or from any of the other spaces may return to an air filtration or disinfectant unit  250 , where the return air may be filtered and/or treated to disinfect it to a selected quality level and then returned to the air system for recirculation. Any air  237  passing to the air system  220  from the outside environment may also be passed through the filtration/disinfectant unit  250 . The filtered/disinfected air  221  passes to the air system  220 .  
         [0039]     In another aspect, the air under pressure may be treated in a treatment unit  240  with a suitable chemical or by using another process that will inhibit the formation of a harmful elements, such humidity, mildew, etc., before supplying the air to an air passage, such as passage  210   a  of wall  204   a  at an opening  214   a , as shown by arrows  231 ,  235  and  239 . A baffle  212   a  may be provided to inhibit entry of the outside air into the air passage  210   a . The air from the passage may discharge at an opening  262 . Air discharging at the opening  262  may first be passed to a chemical unit  260  that traps any harmful chemicals in the air and then allow relatively harmless air to pass to the outside environment, as shown by arrows  273  and  275 .  
         [0040]     A control unit or controller  230 , which may be a microprocessor-based unit, may control the operations of the air system  220  and the treatment unit  240 . In one aspect, the controller  230  may control a valve  234  to control the amount of air from the air system  220  to the treatment unit  240 . In this manner the controller  230  may control the amount of the treated air that passes to the air passage  210   a . In another aspect, the controller  230  may control the supply of air from the air system  220  in response to one or more sensor measurements, such as from temperature, humidity, pressure sensors (generally designated herein as T 1 , T 2 , etc.), which sensors may be placed at any suitable locations in the structure  202 . Signals S 1 , S 2 , etc. from the sensors T 1  and T 2  respectively pass to the controller  230 , which processes the received signals and controls the various operations in response thereto. The control unit also may control the baffles  212   a  and  212   b  as desired.  
         [0041]     Thus in one aspect, a structure is disclosed that may include an air supply system that supplies air under pressure and an enclosed space that has at least one wall having an inner section and an outer section. The inner and outer sections define an air flow passage that is configured to receive at least a portion of the air under pressure at a first opening and discharge at least a portion of such received air to an outside environment via a second opening. The air supply system may supply the air under pressure to the enclosed space and the air flow passage may receive a portion of the air from the enclosed space. The structure also may further include a secondary enclosed space which receives the air from the inner space and then discharge at least a portion of the received air into an air passage, to the outside environment and/or back to the air supply system. The system may further include a filtration and/or disinfectant unit that disinfects air returning from the inner space, one or more of the other enclosed spaces and/or the outside before returning such air to the air supply system. The filtration and/or disinfection unit may use any suitable method that conditions the air for humans. In another aspect, the air under pressure from the air supply system may be treated with a suitable chemical that will inhibit the formation of harmful elements, such as humidity, algae, mildew, etc. in the air passage or along the wall sections. The air supplied may be heated air, cooled air, disinfected air, filtered air, treated with a chemical to inhibit humidity, mildew or bacteria, etc.  
         [0042]     In one aspect, a controller may control the operations for one more aspects of the system of  FIG. 5  in response to one or more sensor measurements an/or in accordance with programmed instructions provided to the controller. Baffles or other suitable devices, mechanically or electrically controlled, may be used to inhibit a flow of outside air into the air flow passages. Also, the air to the air flow passages may be supplied in any suitable manner, including, but not limited to, directly into an opening; via the inner space; from an attic space associated with the inner space; from a unit that is placed outside the structure; from a unit that is placed inside the structure; from a unit that is partially placed inside the structure; and/or from a space adjacent the inner space that receives the air under pressure. Any air passage may enclose additional spaces, which may lie above, below or on the side of the inner space. The air may flow upward, downward or at least partially sideways. In another aspect, the air supply system supplies air to a window of a structure, which includes an inner panel and an outer panel, the inner and outer panels defining an air flow passage that is configured to receive at least a portion of the air under pressure at a first opening and to discharge the received air at a second opening.  
         [0043]     In another aspect, a method for inhibiting moisture in an outer wall of a structure is disclosed, which wall includes air flow passage having a first opening to receive air. The method comprises supplying air under pressure at the first opening and allowing at least a portion of the air supplied under pressure to the air flow passage to discharge to an outside environment from the second opening to inhibit moisture in the outer wall.  
         [0044]     The foregoing description is directed to particular embodiments of the present invention for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope and the spirit of the invention. It is intended that the following claims be interpreted to embrace all such modifications and changes. The abstract is provided to satisfy certain requirements of the patent office and is not intended to limit in any way the scope of the claims.