Patent ID: 7757686

Claim:
In combination: a) an appliance that produces combustion gases during operation and having a flue outlet through which the combustion gases are discharged from the appliance; and b) a vent assembly comprising: a conduit assembly bounding a flow space into which discharged combustion gases from the flue outlet are communicated and from which the discharged combustion gases are exhausted through a vent outlet to a first location, the conduit assembly comprising a first conduit length in which a) the combustion gases are communicated in a first direction in a first path between the flue outlet and the vent outlet; and b) backflow is communicated in the first path in a direction opposite to the first direction, the conduit assembly further comprising a draft control assembly, the draft control assembly comprising a conduit portion defining a flow passage that is part of the flow space and in which backflow is diverted out of the first path and exhausted to a second location that is spaced from the first location, wherein the draft control assembly further comprises a flow guide assembly within the flow space, the flow guide assembly defining a surface for intercepting backflow, moving in the first path opposite to the first direction toward the flue outlet, and through the surface guidingly changing a direction of movement of the intercepted backflow and thereby diverting the backflow into the conduit portion to be exhausted to the second location wherein the conduit assembly has a straight length extending from the flue outlet to and past the flow guide assembly.