Ventilated Roof Apparatus and Method

Abstract

In ventilating a roof, an eave vent and a ridge vent are provided. The eave vent and ridge vent each is equipped with a fabric filter. The fabric filter is not waterproof and is wettable and hence self-cleaning. The permeability to air of the eave vent fabric filter is less than that of the ridge vent fabric filter and the resistance to air flow of the eave vent is greater than that of the ridge vent. The attic space under the roof acts as a manifold, distributing low pressure throughout the attic space.

Description

I. RELATED APPLICATIONS[0001]This application is related to and claims priority from provisional application No. 61 / 337,855 filed Feb. 12, 2010 by the inventor named herein.II. BACKGROUND OF THE INVENTION[0002]A. Field of the Invention[0003]The Invention is an apparatus for ventilating a roof, a roof ventilated using the apparatus of the invention and a method of ventilating a roof using the apparatus.[0004]B. Statement of the Related Art[0005]Moisture trapped in an attic or other space underneath the pitched roof of a structure can damage the roof, can damage the remainder of the structure and can promote growth of mold within the attic. To avoid these effects, the space underneath the roof must be ventilated.[0006]As used in this document, the term ‘attic’ refers to an attic and also refers to any other air space under a roof, such as the space between a ceiling or insulation and a roof deck of a structure equipped with a cathedral ceiling.[0007]During daylight hours, the sun shin...

AI Technical Summary

Benefits of technology

[0018]The apparatus, method and roof of the invention achieve more even ventilation of the attic space by adjusting the air flow resistance of the eave and ridge vents. The resistance to air flow is adjusted so that the resistance to air flow presented by the sum of the ridge vents is less than the resistance to air flow presented by the sum of the eave vents supplying the ridge vents. The entire attic space therefore operates at a negative pressure when the air in the attic is warmed, which negative pressure no one region of the eave vents can relieve. The volume of the attic therefore acts as a large manifold, conveying that negative air pressure to every corner of the attic.

[0024]The fabric of the fabric filter is selected to allow water to pass through the fabric. The fabric is wettable and allows moisture to wick through the fabric and to wet both sides of the fabric, while preventing substantially all droplets of water from traveling through the fabric. Water that has passed through the fabric moves by gravity from the top to the bottom of the fabric. In so doing, the water entrains and carries off dust collected on both the inside and outside surfaces of the fabric. The fabric therefore allows the water to wash the dust from both the inside and the outside surfaces of the fabric, preventing blinding of the fabric filter.

[0026]Attachment of the fabric filter to both the top side and the bottom side of the ridge vent or eave vent allows convenient handling and installation of the fabric filter. Installation of the ridge or eave vent involves nailing through the vent from the top side to the bottom side. Some of the nails penetrate the fabric that is wrapped about the top side and the bottom side of the vent, mechanically securing the two ends of the fabric to the roof. The mechanical connection of the fabric to the roof allows the fabric to withstand high winds without failure.

[0028]Nonetheless, resistance to air flow can be readily adjusted by selecting a fabric filter having an appropriate permeability to air; namely, the resistance to air flow per unit area of the fabric. Selecting a fabric filter for the eave vent that has a low permeability relative to that of the ridge vent allows the air pressure within the attic to remain adequately low so that the attic acts as a manifold, drawing ventilation air through all of the eave vents and while providing adequate ventilation to the entire attic space.

Problems solved by technology

If flow paths exist, but if other flow paths present inadequate resistance to air flow, the air will take the flow path of low resistance.

The remainder of the roof that has a higher resistance to air flow will be starved for ventilation air and will suffer the evils associated with inadequate ventilation, as described above.

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