I inspected a basement furnace that vented <5’ out the side of the house. It terminates 12" higher than the grade, but I wonder if the run is long enough
Combustion air vent clearance, 12” inch minimum & 18” inches for Canada, above highest anticipated snow level and maximum of 24” above roof. runs can be up to 65’ feet if my memory serves me well…
^^^^^ This is what gets missed most often in our area. ^^^^^
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Great point, Larry. Inspectors should pay attention clearances.
Insulation vapour barrier (Kraft paper) orientation facing the wrong direction.
Area at the rim joist, floor joist the vent penetrates is not insulated.
In the Denver metro area, a place that definitely gets snow up to and over 12", the minimum height above grade is 12" and in many parts of the mountains, 16-18".
In practice, the heat from the furnace will keep that concentric vent clear (exceptions can be if the snow-fall dumps while the furnace is between burns and the vent gets covered). The bigger problem is when the exhaust and intake are separate. The intake can get easily covered.
If I was king, I would enforce the 12" above highest anticipated snow levels. Around here that would be around 30" above grade.