High Efficiency Furnace No Outside Air Intake

Install manuals typically show both that way and wit h an outside air intake.

High efficiency furnace no outside 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 that otherwise would have been drawn from the room the furnace is located in. See reference 2 in a sealed combustion system as high efficiency furnaces are designed to be outdoor air is essential since the system does not draw any air from inside of the house. Enerally permissible to install a furnace using indoor air for combustion no outside air intake. High efficiency furnace combustion intake from inside or outside.

Exterior combustion air draw eliminates the useless wasted time that you are now going through. Generally you can pull combustion air either from the interior or exterior. Due to high efficiency furnaceshaving their own fresh air intake no air is drawn from inside your home. Unfortunately the fresh air intake you have described is the second type and does not provide direct combustion air to the furnace room as it is directly connected to the return air plenum for.