The Physics of High-Altitude Furnace Derating
In mountain towns like Coalville and Kamas, the air isn't just thinner—it's physically different for a combustion engine. At 5,600+ feet, the decreased oxygen density means your furnace is breathing "thin air." Without a technical adjustment known as **Derating**, your system is headed for a dangerous mechanical failure.
The Law of Displacement and Oxygen Density
A natural gas furnace is essentially a controlled explosion. For that explosion to be efficient and safe, it requires a precise ratio of fuel to oxygen. At sea level, air is dense and packed with oxygen atoms. At our altitude in Summit County, there are approximately 15-20% fewer oxygen molecules per cubic foot of air. If you feed the furnace the same amount of gas as you would in Los Angeles, there won't be enough oxygen to burn it all. This results in **Incomplete Combustion**.
The Danger: Carbon Monoxide and Sooting
When combustion is incomplete, the furnace produces "soot"—a heavy black carbon deposit—and significantly higher levels of Carbon Monoxide (CO). Soot quickly coats the inside of your heat exchanger, acting as an insulator and preventing heat from entering your home. Worse, it can cause the heat exchanger to overheat and crack, releasing lethal CO into your living space. This is why high-altitude calibration is a non-negotiable safety standard at Hvac Pros Coalville.
The High-Altitude Kit: How We Adjust
To fix this, we perform a technical derate. This involves replacing the gas orifices with smaller versions (to reduce fuel flow) or adjusting the gas manifold pressure to match the available oxygen. We utilize digital combustion analyzers to measure the "Exhaust CO2" and "Excess Air" levels, ensuring the flame is blue, stable, and performing to factory-spec emissions standards.
Anthony Mitchell mandates that every installation in Summit County includes a post-install combustion audit. If your installer didn't use a digital analyzer, your system isn't safe. Demand the technical authority for your home's safety.
About the Author: Anthony Mitchell is the founder of Hvac Pros Coalville and a master of high-altitude mechanical engineering with 25+ years of mountain field experience.