Why your commercial heating bill doesn't add up: the inefficiency most facility teams miss

The November utility bill arrives, and the number is higher than it should be. Occupancy hasn't changed. Setpoints haven't changed. Rates went up a little, but not enough to explain the gap.

For most commercial buildings on the Front Range, the missing piece is inside the air handlers. This FAQ covers the questions facility managers and building engineers ask most when winter energy costs stop adding up.

Why is my commercial HVAC system using so much energy?

The most common hidden cause of high HVAC energy use in commercial buildings is dirty coils. Dust, hydrocarbon deposits, and biological growth coat the coil surface and fins, insulating the coil from the air moving across it. The system has to run longer, and the fans have to work harder, to deliver the same amount of heat.

It rarely shows up as a breakdown. It shows up as a bill that creeps higher every season, with no single event to blame.

How much energy do dirty coils actually waste?

Dirty coils can increase HVAC energy consumption by up to 37 percent, according to EPA data. The U.S. Department of Energy puts the penalty for dirty condenser coils at up to 30 percent.

It doesn't take much buildup to start the clock. A layer of debris just 1/100th of an inch thick can cut coil efficiency by 5 percent. Commercial coils that haven't been cleaned in three or more years are usually carrying far more than that.

Don't coils only matter during cooling season?

No. Air handlers move air across coils all winter, and that is where many commercial buildings lose energy without noticing.

Hot water and steam heating coils foul the same way cooling coils do. Fouled coils also restrict airflow, so supply fans run harder and longer to push air through. A multi-climate study published by NADCA found that HVAC cleaning reduced fan and blower energy use by 41 to 60 percent and improved airflow by 10 to 46 percent. Across a Denver heating season that runs October through April, that fan penalty compounds for six months.

We change our filters regularly. Doesn't that keep the coils clean?

Filters help, but they don't keep coils clean on their own. Fine particulate, grease-laden air, and moisture-driven biological growth get past standard filters and build up deep in the coil, where a visual check of the coil face won't reveal it.

Filter bypass makes it worse. Small gaps around filter racks let unfiltered air go straight to the coil. A building can have a perfect filter schedule and still have coils that haven't truly been clean in years.

Does rising energy use mean our equipment needs to be replaced?

Not necessarily. Equipment that looks like it's failing is often being overworked by fouled coils, not reaching end of life.

Before approving a replacement, find out what a cleaning would recover. Proper coil cleaning reduces strain on compressors, motors, and fans, and routinely extends equipment life by two to four years. On a large air handler, that delay is worth far more than the cost of the cleaning.

What does commercial HVAC coil cleaning actually save?

Commercial HVAC coil cleaning typically pays for itself within a year. CCER clients recover an average of $4.36 for every dollar spent, with an 11-month average payback.

Published results back that up. Augusta University documented $21,000 in annual HVAC energy savings, about 6.7 percent, after cleaning its steam coils, along with a 33 percent drop in coil pressure differential. The University of Wyoming saw total building energy use fall by more than half after a full air handler cleaning.

Colorado Springs Utilities identifies coil cleaning as the maintenance task with the greatest energy benefit across HVAC system types.

How is professional coil cleaning different from pressure washing?

High-pressure washing cleans the surface, can bend fins, and leaves deep buildup in place. CCER uses a medium-pressure, low-volume application of chemistry selected for each site's specific buildup. It penetrates the full depth of the coil, removes the hydrocarbon and oxide deposits water alone can't reach, and is fully recaptured with zero storm drain discharge.

How can I tell if dirty coils are driving up my energy bill?

Watch for these signs:

• Energy use is higher than the same month last year, with similar weather and occupancy
• Air handlers and boilers are running longer to hold setpoint
• Staff or tenants report uneven temperatures or stuffy zones
• Static pressure or pressure drop across the coil has risen
• No one can say when the coils were last professionally cleaned
• If two or more apply, an assessment will show how much of your bill is coming from the coils.

When should you schedule coil cleaning?

Before the year-end rush. December across the Front Range fills quickly with holiday projects and year-end budget work, and contractor calendars close up fast. Booking in November gets your building on the schedule before that happens, while the heating season still has five months of savings left to capture.

Start with a free 15-minute energy assessment. CCER inspects your coils, estimates what cleaning would recover, and gives you a projected ROI before you commit to anything.

(720) 224-3306 · hvaccoilclean.com/free-assessment · Denver and the Front Range