We recently had a VERY old central heating furnace replaced and I noticed that the HVAC installer added the following PVC pipe shortly before the inspector arrived:
The metal vents were already part of the original furnace. I'm confused on what the PVC pipe is for.
I don't think it's the condensation water escape - those are going out both sides of the house. So what is this for and why is a metal vent insufficient? Does this pertain to newer standards/codes?
That pipe looks like an air intake.
All "direct vent" style appliances (high efficiency on-demand water heater, gas fireplace, etc.) have an isolated air intake and it is common to have it suck in air from outside the building so as not to force air infiltration through doors, windows, etc.
Indeed, that is ugly. Our fireplace and tankless water heater have something far more elegant:
The stack on the left is a natural gas tankless water heater. The right is a direct vent natural gas fireplace insert.
Often vent pipes go downward if there is a chance something can go inside. Very common application when roof of the house located under oak trees when acorns can vent down and clog the system
