The intake was just stubbed off the unit in the attic.
Furnace vent pipe through roof.
If your furnace has an afue rating of 90 or lower it probably exhausts the gases though the flue pipe on your roof.
Another problem is that flue pipes that go through the roof tend to be less efficient.
Run the vent pipe up through the roof and install a metal or pvc flashing collar over it.
Match the vent pipe to the furnace maker s recommendations either sheet metal or vinyl.
Push the male end of a new vent pipe up through the bottom of the roof flashing and set its female end on the male end of the vent pipe that connects to the gas furnace.
The only thing terminated through the roof was the exhaust.
That s because the combustion byproducts are in a gaseous form so the gases can float up through the flue pipe and out of your roof.
Twist the roof s vent pipe clockwise one half turn with one hand while holding the gas furnace s vent pipe still with the other hand.
Ambient temperature two ambients must be considered.
Vent pipes provide this air by running outside the structure of the house.
The vents consist of circular or oblong pipe that attaches to a flange on the furnace and extends upward through an attic and passes through a roof flashing.
If your furnace has an afue rating of 90 percent or above it will have a flue pipe that.
High efficiency furnaces take advantage of the heat in the combustion gases that are wasted in natural ventilation systems.
Running a vent pipe out of the roof takes some careful preparation.
On the roof you don t want to turn the exhaust vent down because if the chance of recirculating flue gas back into the combustion air intake.
As stated earlier heat loss through the vent pipe walls can take away from the draft force.
Ok the new efficient furnace requires a pvc vent pipe and the older furnace required a metal type b vent.
The exhaust flue was 2 pipe with two elbows and about 6 in length.
1 avoid an excessive number of turns and bends figure 5 and 2 maximize rise.
If your furnace has an afue rating below 90 percent it will most likely have a flue pipe that goes up through your roof.
First consider the ambient temperature of the air around the vent pipe.
When water drains air must replace the space that was taken up by the water.
Plumbing vent pipes are connected to your drain system and are needed for water to drain properly.
The outer pipe draws air for combustion from outside and the smaller pipe occupies the inner position and is used to vent the exhaust fumes.
Old furnace vents are removed when.