1.   Some are designed to be used with vent hoods.

2.   The standard vent hood that has a four-inch and will not affect the length of the duct run.

3.   The type and size of the vent hood at the end of the duct also affects the total length.

4.   To check the flow, hold a smoking incense stick near the vent hood.

5.   We had a grill cook who was not familiar with the way vent hoods work.

6.   High wind prevented technicians from moving a vent hood into position over the external fuel tank, part of the preparation for filling the tank.