At what elevation should gas appliances have their input reduced by 4% for each 1000 feet above sea level?

Gas appliances should have their input reduced by 4% for each 1000 feet above sea level due to the decrease in atmospheric pressure that occurs at higher elevations. As altitude increases, the density of the air decreases, which affects the combustion process of gas appliances. The correct altitude at which this adjustments should begin is 2,000 feet above sea level.

At elevations higher than this threshold, the air becomes less dense, leading to less oxygen available for combustion. This is why an adjustment in the gas input is necessary to ensure that appliances operate efficiently and safely.

Reducing the input at this elevation helps to maintain the proper air-to-fuel ratio, which is critical for efficient combustion and to prevent issues like incomplete combustion or increased carbon monoxide production. Therefore, understanding that 2,000 feet is the appropriate elevation for when to start applying a reduction helps technicians ensure that appliances are functioning within safe operating parameters as they install or service equipment in elevated areas.