Furnace vent and intake terminal and blockage safety shut down system

A horizontal air intake and combustion gas vent terminal positionable in an exterior wall of a building for admitting outside air to a fuel fired furnace in the building and venting combustion gas therefrom to the outside of the building, the terminal comprising:

• (a) a vent conduit for receiving combustion gases from the furnace, the vent conduit extending along a longitudinal vent axis and having a length and an open vent outlet end positionable to extend outwardly from the exterior wall for venting the combustion gases to the outside of the building, the vent conduit being tapered along the length thereof towards the vent outlet end for accelerating a flow of combustion gas therethrough;
• and
• (b) an intake conduit disposed around the vent conduit and extending along a longitudinal intake axis, the intake conduit having an air flow space defined therein in cooperation with the vent conduit for receiving a horizontal flow of outside air through an open intake inlet end and delivering said air through the air flow space to the furnace, the intake inlet end being positionable between the vent outlet end and the wall;
• and
• (c) wherein the longitudinal vent axis and the longitudinal intake axis are noncoaxial and nonparallel, and the longitudinal vent axis is disposed substantially below the longitudinal intake axis at the vent outlet end.