System and Method for Inhibiting Moisture and Mold in Structures

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

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

1. Field of the Invention

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.

2. Description of the Related Art

In today'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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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

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:

FIG. 1 is a perspective drawing of a structure according to one preferred embodiment of the present invention;

FIG. 2 is a schematic of a structure of a circulation system according to one embodiment of the present invention;

FIG. 3 is a block diagram of another circulation system according to one embodiment of the present invention;

FIG. 4 is a schematic of a functional block diagram for use in the structures according to one embodiment of the present invention; and

FIG. 5 is a schematic diagram showing a circulation system for a structure according to another embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

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.

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.

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.

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 120a and an outside pane 120b with an air passage 120c 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 120c at the opening 116 and discharged at the opening 119 so as to inhibit or eliminate condensation in the space 120c.

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.

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.

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 112a and/or 112b 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.

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.

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.

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.

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.

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 204a that includes an outer section 206a and an inner section 208a and an air passage 210a between these inner and outer sections. Also shown is a second outer wall 204b that has an air passage 210b that is bounded by the inner and outer sections 206b and 208b of the wall 204b. The structures of the walls 204a and 204b 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.

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 210b via an opening 266 and then to the outside environment via an opening 268, as shown by arrows 267. A baffle 212b or another suitable device may be provided to inhibit outside air from entering the air flow passage 210b. 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.

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 210a of wall 204a at an opening 214a, as shown by arrows 231, 235 and 239. A baffle 212a may be provided to inhibit entry of the outside air into the air passage 210a. 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.

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 210a. 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 T₁, T₂, etc.), which sensors may be placed at any suitable locations in the structure 202. Signals S₁, S₂, etc. from the sensors T₁ and T₂ 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 212a and 212b as desired.

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.

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.

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.

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.

Claims

1. A structure, comprising:

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.

2. The structure of claim 1, wherein the air supply system supplies the air under pressure to the inner space and the air flow passage receives the at least a portion of air under pressure from the inner space.

3. The structure of claim 1, wherein the structure further comprises a secondary enclosed space and wherein the air supply system supplies the air under pressure to the inner space, the enclosed secondary space receives the air from the inner space and discharges at least a portion of the air received from the inner space to the outside environment via the air flow passage.

4. The structure of claim 1 further comprising a conditioning unit that disinfects air received from the inner space.

5. The structure of claim 1 further comprising a treatment unit that treats the air under pressure received at the first opening to inhibit formation of one of humidity, mildew and algae.

6. The structure of claim 1, wherein the air supply system supplies conditioned air that is one of: (i) heated air; (ii) cooled air; (iii) disinfected air; and (iv) air treated with a chemical to inhibit humidity, mildew or bacteria.

7. The structure of claim 1, wherein the air supply system comprises a controller that controls the supply of the air under pressure.

8. The structure of claim 7, wherein the controller controls the supply of the air under pressure in response to at least one sensor measurement.

9. The structure of claim 1 further comprising a baffle that controls the flow of the air into the air flow passage from the outside environment.

10. The structure of claim 1, wherein the air supply system supplies the at least a portion of the air under pressure to the air flow passage in a manner that is one of: (i) directly into the first opening; (ii) via the inner space; (iii) from an attic space associated with the inner space; (iv) from a unit that is placed outside the structure; (v) from a unit that placed inside the structure; (vi) from a unit that is partially placed inside the structure; and (vii) from a space adjacent the inner space that receives the air under pressure.

11. The structure of claim 1, wherein the at least one wall further encloses at least one additional inner space above the inner space and wherein the air received by the air flow passage flows in a direction that is one of: (i) upward; (ii) downward; and (iii) at least partially sideways.

12. A structure, comprising:

an air supply system that supplies air under pressure; and

a window unit associated with an enclosed space of a structure, the window including 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 supplied 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.

13. The structure of claim 12, wherein the air flow passage receives the at least a portion of the air under pressure from one of: (i) the enclosed space; (ii) directly from the air supply unit; and (iii) a conditioning unit associated with the air supply system.

14. A system, comprising:

an air supply system configured to supply air under pressure to an air passage in a wall of a structure via a first opening and to discharge at least a portion of the air supplied to the air passage to an outside environment via a second opening.

15. A method of inhibiting moisture in a wall of a structure that includes an air flow passage having a first opening to receive air and a second opening to discharge the received air, the method comprising:

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.

16. The method of claim 15, further comprising supplying the air under pressure to the first opening form one of: (i) a space that is enclosed by the wall; (ii) directly from an air supply system; (iii) an attic associated; (iv) an enclosed space above the first opening; and (v) an enclosed space below the second opening.

17. The method of claim 15, wherein supplying air under pressure to the first opening comprises treating the air supplied under pressure to control one of humidity and mildew before supplying the air under pressure to the first opening.

18. The method of claim 15 further comprising controlling the supply of the air under pressure to the first opening in response to a sensor measurement.

19. The method of claim 15 further comprising inhibiting flow of an outside air into the air flow passage.

20. The method of claim 15, wherein the air flow passage runs along a plurality of floors associated with the structure.