external air intake for oil burner?

Underdog

Is a fresh air intake for oil burners required in some locations? Does this boost efficiency or reduce drafts? Standard practice for newer homes? why bother?

Steamhead

This setup is needed if there is not enough combustion air available. It's possible some local Codes require it. I'd say whoever put it in determined it was needed.

Intplm.

Boiler room fresh air supply may have been found to be inadequate. What can be described as not enough "free air" for proper burner combustion.

EBEBRATT-Ed

Saves fuel...but not much. Without it the burner uses heated basement air and sends it up the flue.

With it the burner uses cold outside air so warm basement air is not lost but the cold air is still heated in the boiler (absorbing fuel) and sent up the flue.

When the boiler is off without the combustion air intake warm basement air leaks into the boiler and up the flue due to the chimney draft. This probably accounts for some savings.

As others have pointed out it is required if the burner does not have access to sufficient combustion air.

Burning 1 gallon of fuel oil requires about 1800 cubic feet of air...quite a bit

Underdog

I've noticed that during my annual oil boiler cleaning, the tech leaves the door to the basement open. One year during annual cleaning the system "failed." It took a while before the problem was discovered. The problem turned out to be that the door at the top of the basement stairs had swung shut, clamping (restricting) air through a hose. We opened the door (un-crimping the hose) and everything registered perfectly. Makes me question if the door needs to be open to get the performance needed. Why did the hose run up the stairs?

EBEBRATT-Ed

When the air intake leaves the boiler where does it go? It should terminate through the sill to the outdoors