Originally Posted By: mbartels This post was automatically imported from our archived forum.
Can a high efficiency gas furnace located in an unfinished attic draw it’s combustion air from the attic or is the intake air required to be from the exterior?
The exhaust vent on said furnace went through the roof. Why did they not bother with extending the intake as well?
Originally Posted By: rcloyd This post was automatically imported from our archived forum.
Matthew:
It is permissible to draw the combustion air from the attic as long as:
1) The attic provides the necessary volume of combustion air.
2) the combustion air opening shall be provided with a metal sleeve
extending from the appliance to at least 6 inches above the top of
the ceiling joists and insulation.
3) The end of the combustion air inlet duct shall not be screened.
