The combustion air intake usually is piped from the exterior of the home to the furnace.
High efficiency furnace combustion air intake.
Since high efficiency furnaces draw air directly from outside the furnace itself does not require a fresh air intake in order to replace inside air.
Department of energy a defining feature of high efficiency furnaces is sealed combustion a process by which outdoor makeup air is piped directly into the burner.
Other aspects of high efficiency furnace venting there are several other important aspects of high efficiency furnace venting.
These types of furnaces have a dedicated pipeline that runs directly from an outside vent into a sealed combustion chamber of the furnace and a sealed vent to the outside of the home for venting the toxic fumes from the combustion process.
Unlike conventional furnaces a condensing furnace often uses a sealed combustion chamber and direct vent combustion air.
The main difference between a conventional furnace and a condensing furnace is the heat exchanger technology used to extract heat from the combustion process and exhaust the combustion gases.
Fortunately you are correct that your new high efficiency furnace should have an integral combustion air intake duct that supplies air directly to the combustion chamber.
According to the u s.
A high efficiency condensing furnace is a little more complex than a conventional furnace and troubleshooting is somewhat more complicated since there are more potential problems.
Due to high efficiency furnaces having their own fresh air intake no air is drawn from inside your home.
However condensing furnaces can also be installed as single pipe non direct vent configurations in which the combustion air is drawn from the indoors.