Gas Heat ESCO Practice Exam

Gas furnaces installed at altitudes above how many feet need adjustments to operate properly?

1. 1,000 feet

2. 2,000 feet

3. 3,000 feet

4. 4,000 feet

The correct answer is: 2,000 feet

The correct answer is that gas furnaces installed at altitudes above 2,000 feet typically need adjustments to operate properly. At higher altitudes, the air pressure is lower, which affects the combustion process of gas appliances. Specifically, the amount of available oxygen decreases, which can lead to incomplete combustion if the furnace is not adjusted appropriately. To ensure safe and efficient operation, adjustments might include modifying the gas valve, changing burner orifices, or making other tweaks to the furnace settings. This optimization is crucial to prevent issues such as poor heating performance, increased emissions, and potential safety hazards, like carbon monoxide production, which can occur if the furnace is not operating correctly in lower oxygen levels. Understanding the need for adjustments at this altitude threshold is important for HVAC professionals to ensure that gas furnaces function efficiently and safely in higher elevation environments.