You can go through the wall then run a vent pipe straight up above the roofline.
Can you vent a gas furnace through a wall.
Adhere to them even if you are building the vent on your own.
The exhaust gas is too cool for it to rise.
Gas furnaces usually come with their own specifications.
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.
You cannot just take the vent off an 80 efficient furnace and run it out a side wall.
The answer is yes and no.
Only units designed for it can have a vent go thru the wall and end there without a vertical stack.
When installing a direct vent wall furnace there will be two sets of clearance distances that must be respected.
So what does this mean.
These ventilation pipes should be isolated from the furnace combustion chamber and made airtight to eliminate the possibility of combustion gas leakage.
Proper sidewall venting requires installing separate vent pipes horizontally so that they vent to the outdoors through a wall of your home.
The vent pipe must overlap at each joint to prevent gas from leaking.
I have not heard of high efficieny only lasting 10 13 years.
Distances pertaining to the furnace combustion air intake and exhaust vent distances from the indoor furnace cabinet itself and nearby surfaces materials or combustibles.
I would be very leary of a hvac contractor would not do this.