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?