If you live in Denver, you’re likely acclimated to its weather and altitude. The human body is fantastically adaptable. However, your home’s furnace can’t adapt to the altitude here on its own. To achieve the performance you expect, furnaces here need modifications to account for the altitude and its effects. Here’s everything you need to know about the effects of Denver’s altitude on your furnace.
How High Altitudes Effect Furnaces
Here in the Mile High City, the average air density is approximately 18% lower than what you’d expect at sea level. It’s why visitors can get winded during short walks that locals can handle with ease. After living here for a while, you probably don’t notice it at all. However, that just means your body has adapted to using less oxygen. Inside your furnace, reduced oxygen completely alters the combustion process.
If you were to install a standard gas furnace in a Denver home, its burners wouldn’t be very efficient. It would operate with an incorrect air-to-gas ratio, leading to incomplete combustion. That, in turn, increases wasted fuel and decreases heat output. It also increases the production of dangerous combustion byproducts, such as carbon monoxide. You can also expect accelerated soot buildup on the furnace’s burners and combustion chamber, further harming efficiency.
How to Tell if Your Furnace Needs an Altitude Adjustment
Incomplete combustion in your furnace may produce some other signs you should watch for. One is an orange burner flame. Newer furnaces often have a small, clear viewport in their burner access doors. That lets you see how the burners operate while your furnace runs. When your furnace is working as it should, the burners should emit a light blue flame. If you see any other color, it’s a sign of incomplete combustion. Often, it’s due to an improper air-to-gas ratio.
In some cases, your furnace may even struggle to start when called upon. That happens because the furnace’s ignition system can’t work until sufficient oxygen enters the combustion chamber. While it waits, unburnt gas will build up inside. Eventually, when the ignition happens, you may hear a loud boom. The sound is that of a small gas explosion. While it isn’t typically dangerous, it isn’t something you should ignore.
How Furnace Derating Helps
The process of adapting a furnace to work properly at high altitude has a name: derating. It involves adjustments that correct the mixture of oxygen and fuel inside the furnace’s combustion chamber. You can derate most furnaces by reducing gas flow via a built-in regulator. In some cases, derating also requires changes to the size of the furnace burner orifices.
It’s important to know that derating isn’t without consequence. By reducing fuel flow, you’re also decreasing heat output below the manufacturer’s specifications. In general, you can expect a furnace to lose about 4% of its rated heat output for every 1000-foot increase in elevation. Here in Denver, that means sacrificing roughly 21% of your furnace’s rated output. If the installer of your furnace never accounted for that, you may find yourself stuck with an undersized furnace. Unfortunately, there’s no solution to that but a replacement.
The good news is that you can expect some great benefits from derating your furnace. One is that it should operate at its original promised efficiency. Another is that you’ll extend your furnace’s lifespan and reduce its need for repairs over time. You’ll also enjoy safer operation, since you’ll be reducing the odds of a deadly carbon monoxide leak in your home.
High-Altitude Furnace Experts
For 18 years, Unique Heating & Air Conditioning Inc. has installed and serviced furnaces all over Denver. Our team of expert, NATE-certified HVAC technicians is well-trained and has ample on-the-job experience. You can also count on us to service any make or model furnace you own. Plus, we offer a 100% satisfaction guarantee on our work, so you can be sure you get what you pay for. Our Better Business Bureau accreditation and A+ rating offer further proof of that. And if you need a new furnace, we can provide financing options on approved credit to help you afford one. So, if you suspect your home’s furnace needs adjustments to handle Denver’s high altitude, contact Unique Heating & Air Conditioning Inc. today!
