The two systems use different venting systems.
High efficiency furnace venting through roof.
When the vent is withdrawing air from the house it expels the gas outside through the vent.
If your furnace has an afue rating of 90 percent or above it will have a flue pipe that goes out of the side of your house.
If you are venting a high efficient furnace with the pvc piping you can go through a roof or wall.
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.
If your furnace has an afue rating below 90 percent it will most likely have a flue pipe that goes up through your roof.
Depending on the installation a high efficiency furnace will have at least one and sometimes two pvc pipes exiting the home.
Since it takes less energy to move the cooled exhaust horizontally he furnaces typically exhaust to the side of a building rather than the top.
As the gases are cooler pvc cpvc or abs piping can be used to carry the exhaust to the outside.
This residual liquid is highly acidic.
It uses a venting system to extract that heat before venting.
This structure generally uses the furnace vent pipe through roofbecause the b venting pipe is designed in vertical manner.
In newly built homes these vents will usually exit thru the roof.
A high efficiency condensing furnace can achieve efficiency ratings of 90 or above.
A high efficiency furnace uses a different type of venting system because it extracts the heat that remains in those combustion gases before venting the resultant mixture of water and carbon dioxide.
Run the vent pipe up through the roof and install a metal or pvc flashing collar over it.
Also known as the type b this vent is operating on the natural air convection.
It is easier to go through the wall next to the furnace and makes it a lot easier to deal with.
Match the vent pipe to the furnace maker s recommendations either sheet metal or vinyl.
If you notice water on the floor around your high efficiency furnace or water or rust stains within the cabinet your furnace is not draining properly.
It s a high efficiency gas furnace and that s the exhaust vent.