How long has this code been in effect? Is it the state or city? I was in NY last year and replaced a system for some friends, It was installed in 86 when the entire town house development was built. Every system there had black ABS on the drains and it was ran over into the washing machine standpipe.
What if the system uses a condensate pump? does the clear vinyl hose fall into the category?
Just curious! I wonder if this is code in other states? All other states I worked in used plastic.
In NY, you cant use PVC for a drain. It has to be copper or black pipe. Sucks huh?
I've seen this for the interior due to smoke given off during a potential fire but typically if it is outside, you can use pvc. Although I think that is the last thing the inspector would care about on this unit!