One of the most impactful — and most overlooked — commercial HVAC maintenance tasks is routine coil cleaning. Dirty condenser and evaporator coils don’t just reduce comfort; they silently drain hundreds or thousands of dollars from your energy budget every year while accelerating the deterioration of the most expensive component in your system: the compressor.
For commercial buildings in Metro Detroit, Livonia, and throughout Southeast Michigan, Samco Facilities Maintenance provides professional AC coil cleaning services that restore system efficiency and extend equipment life. Here’s what you need to know.
What Are AC Coils and Why Do They Get Dirty?
Your commercial HVAC system contains two types of coils that work together to move heat:
- Evaporator coils (inside your building) absorb heat from indoor air as refrigerant evaporates inside them. They’re located in the air handler or indoor unit.
- Condenser coils (outside or on the rooftop) release that heat to the outdoor air as refrigerant condenses. On rooftop package units, they face the ambient environment.
Both types collect contaminants over time. Condenser coils accumulate airborne debris, cottonwood seeds (a serious problem in Michigan from May through June), bird droppings, and pollutants. Evaporator coils collect dust, mold, bacteria, and in commercial kitchens, grease — the most damaging contaminant of all for coil surfaces.
The Real Cost of Dirty Commercial HVAC Coils
The energy penalty from dirty coils is not a minor issue. Research from the Air-Conditioning, Heating and Refrigeration Institute (AHRI) and real-world commercial HVAC data consistently show:
- Condenser coils with a 0.042-inch fouling layer reduce system capacity by 13% and efficiency by 21%
- Evaporator coil fouling with grease film as thin as 0.002 inches reduces heat transfer by up to 40%
- A commercial system running with dirty coils uses 30-40% more energy to achieve the same cooling — often translating to $500-$3,000 per year in wasted electricity for a mid-size commercial building
Beyond energy costs, compressors operating against dirty coils run hotter and at higher discharge pressures. This thermal stress is the leading cause of premature compressor failure — a repair that typically costs $2,500-$8,000 on a commercial rooftop unit. Regular coil cleaning is, quite simply, the most cost-effective compressor protection you can buy.
Signs Your Commercial AC Coils Need Cleaning
Don’t wait for a visible coating of dirt. These operational symptoms indicate coil fouling:
- Higher energy bills without explanation — if your utility costs are up 15-30% compared to the same period last year and usage hasn’t changed, coil fouling is a prime suspect
- Longer run times and short-cycling — the system runs longer to achieve setpoint temperatures, or starts and stops frequently
- Inadequate cooling — rooms that used to reach setpoint easily now struggle, especially during peak summer heat
- Ice formation on coils — severe evaporator coil fouling restricts airflow and can cause the coil to freeze over
- High discharge pressures — technicians can verify this during a service call; elevated head pressure is a direct indicator of condenser coil fouling
- Unusual odors from supply registers — musty smells from evaporator coils suggest biological growth (mold, bacteria) in addition to dust fouling
How Professional Commercial Coil Cleaning Works
DIY coil cleaning with a garden hose and off-the-shelf coil cleaner spray is fine for light residential maintenance. For commercial systems, it’s rarely adequate — and in some cases, it can cause damage if done incorrectly. Here’s what a professional commercial coil cleaning involves:
Condenser Coil Cleaning (Rooftop and Outdoor Units)
- System shutdown and safety lockout — power is isolated before any coil work begins
- Debris removal — loose debris, cottonwood, leaves, and bird nesting material are removed by hand and with compressed air
- Chemical application — a commercial-grade alkaline or acid coil cleaner is applied (product selection depends on coil material — aluminum fins require pH-neutral cleaners to prevent corrosion)
- Dwell time — cleaner penetrates the fouling layer for 5-15 minutes depending on severity
- Low-pressure rinse — coils are rinsed from the inside out to flush contaminants through without damaging fins. High-pressure washing can bend aluminum fins, reducing airflow.
- Fin straightening — a fin comb is used to straighten any bent fins, restoring design airflow
- Documentation — before and after photos, condition notes for the maintenance record
Evaporator Coil Cleaning (Indoor Units and Air Handlers)
- Access panel removal — the air handler is opened to expose the evaporator coil
- Dry cleaning — loose dust is vacuumed from coil surfaces and surrounding areas
- Chemical application — no-rinse evaporator coil cleaner is applied to the coil face. In heavy-grease environments, a degreaser pretreatment may be required first.
- Drain pan cleaning — the condensate drain pan is cleaned and treated with biocide tablets to prevent algae growth and clogs
- Drain line flush — the condensate drain line is flushed to ensure clear drainage and prevent water damage
- Coil treatment — an optional anti-microbial coating can be applied in environments prone to biological growth
How Often Should Commercial AC Coils Be Cleaned?
The right cleaning frequency depends on your environment:
| Environment Type | Condenser Coils | Evaporator Coils |
|---|---|---|
| Standard office / retail | Annually (spring) | Annually |
| High-traffic retail / gym | 2x per year | 2x per year |
| Restaurant / food service | 2-4x per year | Every 3 months (minimum) |
| Near cottonwood trees (MI) | May/June + Fall | Annually |
| Industrial / dusty environments | Quarterly | Quarterly |
For Michigan commercial buildings, we recommend at minimum annual condenser coil cleaning in late spring (after cottonwood season) and evaporator coil cleaning each fall before heating season. Restaurant and food service operations need evaporator coil cleaning every 60-90 days without exception.
AC Coil Cleaning as Part of a PM Program
Coil cleaning shouldn’t be a standalone service — it’s most effective and most economical when incorporated into a comprehensive preventive maintenance program. At Samco FM, our commercial HVAC PM programs include:
- Scheduled coil cleaning at appropriate intervals for your facility type
- Filter replacements and air handler inspections
- Refrigerant level checks and leak screening
- Electrical component inspection (contactors, capacitors, wiring)
- Condensate drain cleaning and treatment
- Controls and thermostat calibration
- Belt and bearing inspection on older units
- Complete service documentation for warranty and compliance purposes
PM program members also receive priority scheduling for emergency service calls — which means if your system goes down at 2 a.m. on a Saturday in July, you’re at the front of the line.
Commercial Coil Cleaning Service Areas
Samco FM provides commercial AC coil cleaning and HVAC maintenance services throughout Metro Detroit and Southeast Michigan, including:
- Livonia and western Wayne County
- Detroit and the greater Detroit metro
- Farmington Hills, Novi, and Northville
- Dearborn, Westland, and Plymouth
- Ann Arbor and Washtenaw County
- Troy, Southfield, and Oakland County
- Warren, Sterling Heights, and Macomb County
Frequently Asked Questions: Commercial Coil Cleaning
How long does a commercial coil cleaning take?
A standard rooftop unit coil cleaning typically takes 45-90 minutes per unit. Large air handler coil cleanings can take 2-4 hours depending on access and coil size. We schedule commercial coil cleaning during low-occupancy periods when possible to minimize operational disruption.
Do you clean coils on all commercial HVAC brands?
Yes. Our technicians are trained on all major commercial HVAC brands including Carrier, Trane, Lennox, York, Daikin, Mitsubishi, and Rheem. Coil cleaning procedures are similar across brands — the key variables are coil material, fin density, and accessibility.
What’s the difference between a coil cleaning and a tune-up?
A tune-up typically includes coil cleaning plus a broader inspection of electrical components, refrigerant levels, controls, and other system elements. Coil cleaning alone is appropriate when the system is otherwise well-maintained and you specifically need to address fouling. We can advise on the right service scope after a brief phone conversation about your system’s condition and maintenance history.
Will coil cleaning void my equipment warranty?
No — in fact, most commercial HVAC manufacturers require documented preventive maintenance (including coil cleaning) to keep warranties valid. Our technicians document all work performed, which protects your warranty coverage.
Schedule Commercial AC Coil Cleaning in Metro Detroit
Dirty coils are costing you money right now. A professional coil cleaning from Samco FM typically recovers its cost in energy savings within the first cooling season — and the equipment protection it provides lasts for years.
Contact Samco FM today to schedule commercial AC coil cleaning for your Metro Detroit facility. Call (734) 838-6300 — available 24/7 for emergency HVAC service.
Samco Facilities Maintenance has provided commercial HVAC service across Southeast Michigan since 1997. EPA Section 608 Universal certified. NATE certified technicians. BBB A+ rated. 4.9 stars across 255+ Google reviews.