Combustion Air Ducts, Part I: Why Houses Need Them. Homeowners, builders, and insulation contractors spend lots of time trying to seal up every little air leak in to a house, ...

Vertical combustion air ducts are also required by code for one duct to be within 12 inches of the top and bottom of the mechanical room. These ducts are usually terminated to the outdoors or an area ...

The combustion air duct should never be blocked. To reduce the amount of cold air that flows in, place the discharge end of the duct into a large wastebasket or box.

Draft testing helps determine if the flue functions as intended. It also identifies external influences that lead to spillage and backdrafting, such as duct leakage and exhaust fans. This ...

For nearly all duct burners, the GT is the source of combustion air. Accordingly, burner performance depends largely on the flow and composition of turbine exhaust gas (TEG).

There's no reason anyone needs to live with a noisy furnace. All furnaces produce a certain amount of noise, largely because of air movement through the ductwork, but that's about all you should hear.

Figure 4. Transition duct cracking before repair. The crews also repaired a crack in a generator lubricating oil line, whose discovery came from inspections apart from those of the duct and stack.

Dear Ken: When we got a new furnace, they installed two big ducts through the outside wall. I’m thinking of blocking them up because they let in so much cold Around the House: Options for ...

A unique design feature of turbofan engines is something called the bypass duct which is located around the engines. Besides ...

Since the chimney and the combustion air duct must pass through those surfaces, make every effort to avoid cutting any rafters or floor joists. If this isn’t possible, ...

The throttle body is a vital component of a fuel-injected internal combustion ... and allow the inside of the throttle body to air dry for at least 10 to 15 minutes before reinstalling the air duct.

Ducts carry heated or cooled air. Under normal operation, they don't carry combustion byproducts and are sealed as a matter of energy efficiency, not combustion safety. Sheetmetal flue pipes, on th ...