Read past posts, and I’m still confused. Is this proper, allowed, etc. etc. ??? If wrong, how would you write it up?
Note- It was a high efficiency furnace.
It is wrong and amateurishly done.
It cannot be connected directly. It must be indirect with an air gap.
Recommend correction.
The problem is that the trap will dry out in the winter time unless it’s a high-efficiency furnace that produces condensate in the heating mode.
The trap must be a wet trap design, meaning that the trap will remain sealed by some water source, other than the HVAC system.
Is the furnace an up flow or down flow configuration?
Up flow causes positive air pressure during operation, down flow causes negative pressure and will suck sewer gases into the air handling system and distribute them throughout the house.
Nothing in code against it, but indirect waste receptors are not recommended for crawl spaces. Releases humidity into the already humid air there.
Recommend that it terminate outdoors 6 to 12 inches above grade where it can be routinely monitored.
The international mechanical code refers to manufacturers installation instructions.
I agree.
The correction should be determined by the specialist.
Was the furnace in the crawl?
That line looks huge. Looks more like a waste pipe. A typical condensation line is only 1 inch.
I normally see primary condensation lines terminating next to the condenser.