The answer is yes and no.
Can you vent a 80 furnace through a wall.
What vent pipe is required on top of a furnace.
An 80 efficient furnace can be side wall vented per national fuel as code 7 3 4 with the use of a mechanical draft system of either forced or induced draft design.
Be sure to check the clearance distances required for your particular heater brand and model.
So what does this mean.
Also known as the type b this vent is operating on the natural air convection.
Always go by the manufactures installation instructions in short no even if it had a combustion blower as in some 80 furnaces they need a vertical vent to operate as intended and be to code.
The barometric damper will prevent pulling additional excess air through the furnace.
You need to use an auxiliary power inducer.
When the vent is withdrawing air from the house it expels the gas outside through the vent.
It could either go out the unused walled in chimney that the oil furnace was vented through or they could cut a hole in the concrete block wall and vent it out the side of the house.
You cannot just take the vent off an 80 efficient furnace and run it out a side wall.
The wall mount direct vent gas furnace exhaust vent outdoor clearance distances shown in our illustration below are an example adapated from williams 2018.
This structure generally uses the furnace vent pipe through roofbecause the b venting pipe is designed in vertical manner.
Replacing a gas furnace whether a wall or forced air furnace requires the appropriate venting to protect your family from carbon monoxide poisoning.
The combustion air flow through the furnace must be controlled or its efficiency will decline.
Example of outdoor and through wall clearances for a direct vent wall mount gas furnace.
The basement ceiling is about 6 1 2 or 7 feet high.
If it went out the chimney it would leave more headroom.