If you trace this duct down, you'll find that it connects to an opening at the exterior of the building. This is essentially just a hole in the side of the building that brings in fresh outdoor air.

Adequate combustion air supply is a critical aspect of safe operation for any fuel-fired equipment. To provide this essential component, openings constructed of metal ducts or fixed grilles are ...

Q We had to put a new furnace in our home and they put in a flexible tube from the outside to the furnace. It was to supply fresh air for the furnace, but it seems to me like having an open window in ...

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 air. Brrrrrr. Is this really required? Can ...

Combustion issues can be a service technician’s most challenging and intimidating problem to diagnose. Unless you’re equipped with the proper skills to tackle these issues, it’s easy to become ...