What is the maximum allowable temperature rise through a furnace heat exchanger?

The maximum allowable temperature rise through a furnace heat exchanger is established to ensure efficiency, safety, and proper functioning of the heating system. A temperature rise of 70°F is typically the accepted standard in many HVAC industry guidelines.

This limit helps to maintain the integrity of the heat exchanger materials and prevents overheating, which could lead to fatigue and premature failure of the equipment. Exceeding this temperature rise could compromise the system’s efficiency, cause discomfort due to fluctuating temperatures, and pose safety risks.

In contrast, exceeding a 70°F rise, as seen with the other options stated, could lead to operational issues, including potential damage to the furnace components as well as higher energy consumption, which is neither efficient nor cost-effective for the homeowner. Understanding these standards is crucial for ensuring that heating systems operate within safe and efficient parameters.