What is typically required for a condensing gas furnace?

A condensing gas furnace is designed to utilize the heat from combustion gases more effectively than traditional furnaces. One of the key features of a condensing furnace is that it lowers flue gas temperatures during combustion. This process leads to the production of condensate — water that is formed when the combustion gases are cooled below their dew point.

To manage this condensate, a dedicated condensate drain is essential. This drain ensures the safe and effective removal of the acidic water, preventing potential damage to the furnace components and the surrounding environment. Thus, having a condensate drain is critical for the proper operation and maintenance of the condensing gas furnace, making it the correct answer to the question. This consideration also highlights the advanced efficiency and design aspects that distinguish condensing furnaces from traditional models, which often rely on higher exhaust temperatures and simply vent gases through a chimney.