I'm not talking about this.High-efficiency furnace creates exhaust that has condensation in it it's a product from the flue gas going through a secondary heat exchanger it's not created inside any cold pipe.
Condensation is also created in the exhaust pipe when it goes outside the house. The cold temperature outside makes the exhaust pipe cold. This is why there's a drain line at the end of the inducer motor and not before. This is also why the exhaust pipe must also be sloped downwards towards the furnace so the condensate makes it's way down the pipe and into the drain catch line at the neck of the inducer.