What is the reduction percentage for gas appliances input used at elevations above 2,000 feet?

When dealing with gas appliances at elevations above 2,000 feet, it's essential to account for the decrease in atmospheric pressure as elevation increases. The proper adjustment for gas appliances is to reduce their input to ensure optimal performance and safety since high elevations reduce the density of the air, which can affect combustion efficiency.

For elevations above 2,000 feet, the accepted standard is to decrease the gas appliance input by 4% for each additional 1,000 feet. This reduction is vital to maintain the correct gas-to-air ratio for combustion and to ensure that the appliance operates correctly and safely without producing harmful emissions or inefficient burning.

Thus, the choice indicating a reduction of 4% for every 1,000 feet is accurate and aligns with established guidelines for gas appliance installation and operation at varying elevations.