Termination for a Direct Vent Gas Burning Appliances Under 4,000 BTU Input.
Prior art is configured using concentric intake and exhaust where both intake and exhaust commute to atmosphere outside a building structure. Concentric passageways are constructed to be coaxial, one pipe within another. Various outside configurations, external to the building structure, are used to shield intake and exhaust gases in order to nullify the effects of outside (atmospheric) air, also known as weather conditions. Intake air is fresh air from outside a building structure. Exhaust is a combination of gases that are the product of a gas fuel burning or the oxidation reduction reaction that occurs when gas fuel is combined with oxygen found in air.
Prior art describes direct vent as communicating with the atmosphere outside a building. Direct vent systems combine the intake and the exhaust pipes into one concentric pipe. Prior art oversizes both exhaust and air intake pipes used for direct venting. In some prior art, exhaust gas moves into a single fitting where intake and exhaust may mingle, and where it dilutes the exhaust gases with intake air before exhausting to the atmosphere.
Prior art uses concentric piping arrangements for the convenience of making one penetration in the building structure. Concentric intake and exhaust is an interior coaxial passageway and a coaxial outer passageway. Both intake and exhaust share a single penetration that allows intake and exhaust to commute to the atmosphere outside a building structure.
Direct vent systems use various types of termination to communicate to the atmosphere outside a building. Termination is that part of the direct vent system that extends outside a building structure and is known as the point of entry for intake air and the point of exit for exhaust air. In termination systems of this type, illustrated in Valters U.S. Pat. No. 5,562,088 the combustion chamber within which the exhaust gases are generated, vents directly through an outside wall to the atmosphere outside of the building structure. Exhaust gases are piped through the center of an intake pipe, coaxially, where the intake commutes atmospheric air to support the combustion (burning) of a gas flame. In this prior art example the termination is attached to the outside of a building where the intake commutes atmospheric air to the gas flame and the exhaust commutes to the atmosphere through the concentric pipe that runs through the center of the intake pipe, coaxially. The termination holds both intake and exhaust pipes in a housing.
The affects of wind, drafts, and air pressure differences caused by the outside atmosphere that are relative to the intake and exhaust of a gas burning appliance create pressure differences large enough to affect the flow of intake air to the gas fuel burning process. The burning, or oxidation reduction reaction, of propane or natural gas requires atmospheric air. The resulting exhaust gases from burning are a mix of carbon dioxide, carbon monoxide, unused air, and other trace gases. A gas flame is burned within a vessel typically referred to as a burner box that receives intake air and contains the burning gas which results in exhaust. Smaller gas burning devices are affected by slight differences in the flow of intake and exhaust gases that, sometimes, result in extinguishing the gas flame. Small gas burners have low BTU input and are more susceptible to the affects of atmospheric, or fluid, pressure differences caused by atmospheric turbulence, or weather conditions.
This invention, the gas exchange termination assembly, is a termination design that maintains a neutral pressure inside a burner and overcomes the affects of atmospheric fluid turbulence, or weather caused air pressure differences. The solution is attributed to the construction and configuration of the termination. The combination of slots for the exhaust and round openings in the intake, maintains a balanced pressure in the burner. The novel construction also includes an exhaust plug that requires exhaust gas to turn 90 degrees to the exhaust flow through the exhaust pipe to move the exhaust through the slots. Slots are positioned in the exhaust pipe to allow exhaust gas to move vertically up and down to exit. Rain and moisture drains from the bottom exhaust slots. Openings are placed in the intake air hood, a metal awning-shape feature, of the exhaust gas termination assembly so that intake air moves through them at varying angles to the flow of intake air in the intake air pipe. Placement of openings in the intake air hood and slots in the exhaust pipe reduce the pressure differential affect between exhaust and intake.
The gas exchange termination assembly is a wall mounted assembly that incorporates both the concentric commuting of intake and exhaust gases to and from a gas flame within a burner box. In this example, atmospheric air moves from outside a building structure to a burner where products of combustion are produced. The process of combustion occurs within the burner box by burning either propane or natural gas fuels. Exhaust gases are vented from the burner box to the outside through the exhaust pipe. Direct venting implies that commuting of intake and exhaust is sealed to and from the burner so that no gas is drawn from inside the building and exhaust is not allowed to vent into the building. The invention, the gas exchange termination assembly, includes a wall mounted assembly of intake air and exhaust pipes that are configured concentrically (one within the other) and require a single penetration through the wall for installation. The gas exchange termination assembly is secured to the wall using appropriate fasteners having a length necessary to penetrate the sheathing and connect to framing studs or structural substrata of the wall.
The invention helps to prevent a gas flame from being extinguished by too much gas movement caused by atmospheric disturbance, weather, that affect the intake and exhaust of a small BTU input gas burner. The invention maintains a neutral pressure at the flame within the burner box. Gases are able to burn more efficiently by allowing intake air and combustion gases to move with minimal interference from the affects of atmospheric disturbance, known as weather conditions.
The invention is called a gas exchange termination assembly. The gas exchange termination assembly is an assemblage of parts, 11, 12, 15, 16, 17, 18 & 19 in
The gas exchange termination assembly is comprised of an exhaust pipe 15—
For sake of illustration of the invention, the intake air hood shows a total of seven combined intake air openings in drawings
The exhaust pipe 15—
10—Intake Air Hood
11—Intake Air Pipe
12—Intake Air Openings (in Intake Air Hood), 7 Openings Shown
13—(Not Shown)
14—(Not Shown)
15—Exhaust Pipe
16—Pin (to hold Exhaust Pipe from moving toward inside of building)
17—Fasteners (to secure gas exchange termination assembly to building)
18—Plug (inside Exhaust Pipe)
19—Slots (top and bottom of Exhaust Pipe), 14 Slots Shown
20—Building or Structure Wall (ancillary to the invention)
21—Interconnecting Flexible Intake Air Pipe (ancillary to the invention)
22—Intake Air Pipe (from flexible pipe to burner box) (ancillary to the invention)
23—Insulation Pack (protects exhaust pipe from burner box) (ancillary to the invention)
24—Burner Box (also known as Combustion Chamber) (ancillary to the invention)