Air Conditioner Coil Cleaning – How We Do It
Service Overview
- Average Cost: KES 2,500 – 6,000 for both evaporator and condenser coils
- Service Duration: 1.5 – 3 hours depending on accessibility and coil condition
- Frequency Recommended: Annually minimum, bi-annually in dusty environments
- Efficiency Impact: Can improve cooling efficiency by 15-30%
- Methods Used: Chemical cleaning, pressure washing, steam cleaning
- Additional Benefits: Reduced energy bills, extended equipment life, improved air quality
Air conditioner coils serve as the critical heat exchange surfaces that make cooling possible, yet they’re often the most neglected components in AC systems. Dirty coils dramatically reduce efficiency, increase operating costs, and shorten equipment lifespan. Our comprehensive coil cleaning process restores heat transfer capability, ensuring your air conditioner operates at peak efficiency while delivering maximum comfort.
Understanding Coil Contamination
Air conditioners contain two primary coil assemblies working together to transfer heat. The evaporator coil sits inside your home within the air handler, absorbing heat from indoor air as refrigerant evaporates within its tubes. The condenser coil resides in the outdoor unit, releasing captured heat to outside air as refrigerant condenses back to liquid. Both coils accumulate different types of contamination that impede their heat transfer function.
Indoor evaporator coils collect dust, pet dander, cooking oils, and biological growth like mold and mildew despite air filtration. This contamination forms an insulating layer on coil surfaces, dramatically reducing their ability to absorb heat from passing air. Restricted airflow through dirty coils forces the system to run longer, increases humidity levels due to inadequate dehumidification, and can cause coils to freeze as restricted airflow drops temperatures below freezing.
Outdoor condenser coils face different challenges including cottonwood seeds, grass clippings, leaves, industrial fallout, and salt spray in coastal areas. This contamination blocks airflow between coil fins and coats surfaces with material that insulates against heat release. Severely fouled condenser coils cause high system pressures that stress the compressor and reduce cooling capacity, sometimes by half or more compared to clean coils.
Pre-Cleaning Assessment and Preparation
Our coil cleaning service begins with thorough system assessment. We measure operating pressures and temperatures before cleaning, documenting baseline performance for comparison after service. This data quantifies cleaning effectiveness and identifies any additional issues affecting system performance. We photograph coil conditions for our records and to show customers the contamination levels affecting their equipment.
Power to the air conditioning system is shut off and locked out for safety. We protect surrounding areas with drop cloths and plastic sheeting, as coil cleaning involves water and chemicals that could damage flooring, walls, or furnishings. For indoor coil cleaning, we often seal ductwork temporarily to prevent cleaning solutions from entering the duct system where they could damage insulation or create odors.
We inspect coils carefully before cleaning, checking for fin damage, refrigerant leaks, or corrosion that might be hidden by contamination. Bent fins are straightened using specialized fin combs that restore proper spacing and airflow patterns. This mechanical preparation is crucial because cleaning cannot correct physical damage that restricts airflow.
Evaporator Coil Deep Cleaning
Accessing evaporator coils often requires removing furnace or air handler access panels and sometimes temporarily disconnecting ductwork. The coils typically sit in cramped spaces requiring careful work to avoid damage. We begin by vacuuming loose dust and debris from coil surfaces and the surrounding cabinet using HEPA-filtered vacuums that capture fine particles without releasing them back into the air.
We apply specialized evaporator coil cleaner formulated to dissolve organic contamination without harming aluminum fins or copper tubing. These foaming cleaners cling to vertical coil surfaces, providing extended contact time for chemical action to break down stubborn deposits. The cleaning solution penetrates between tightly spaced fins, reaching contamination that surface cleaning cannot address.
After appropriate dwell time, we rinse coils thoroughly using controlled pressure and carefully directed water flow. Too much pressure or improper direction damages delicate fins and forces water into areas where it shouldn’t go. We continue rinsing until water runs clear, indicating all cleaning solution and dissolved contamination have been removed. The drain pan and drain line receive simultaneous cleaning since disturbed contamination often washes into the drain system.
For heavily contaminated coils showing biological growth, we apply EPA-registered antimicrobial treatments after cleaning. These treatments kill remaining mold and mildew spores and provide residual protection against future growth. This step is particularly important for indoor air quality as biological contamination in evaporator coils contributes to musty odors and can aggravate allergies and respiratory conditions.
Condenser Coil Exterior Cleaning
Outdoor condenser coils present different cleaning challenges due to their location and the nature of contamination they collect. We start by removing the outdoor unit’s top fan assembly to access the coil from above, allowing top-down cleaning that works with gravity rather than against it. Loose debris like leaves and grass clippings are removed manually or with compressed air blown from inside the coil outward.
We apply heavy-duty condenser coil cleaner designed to handle grease, industrial fallout, and mineral deposits that resist simple water cleaning. These alkaline cleaners break down organic materials and emulsify oils, allowing them to be rinsed away. The cleaner is applied evenly across all coil surfaces, including hard-to-reach areas between the coil and cabinet walls where contamination often accumulates heavily.
Pressure washing removes dissolved contamination, but technique is critical. We use adjustable pressure equipment set to levels that thoroughly clean without bending fins or forcing water past coil seals into electrical components. Water is directed straight through fins from outside to inside, the opposite direction of normal airflow, which most effectively removes impacted debris. We work systematically around the entire coil perimeter, ensuring no areas are missed.
Particularly stubborn contamination may require multiple cleaning and rinsing cycles or alternative methods like steam cleaning. Steam provides cleaning power without high pressure that could damage fins, making it ideal for delicate coils or those with significant fin damage. After thorough rinsing, we inspect coils in bright light to verify complete contamination removal and identify any areas needing additional attention.
Fin Straightening and Airflow Restoration
Even after chemical cleaning removes contamination, bent or crushed fins restrict airflow and reduce coil effectiveness. We use fin combs matched to the specific fin spacing of your coils, carefully straightening damaged areas. This tedious work pays dividends in restored airflow and improved heat transfer. Severely damaged fin sections may be beyond repair, but even partial restoration significantly improves performance.
We pay special attention to coil edges and corners where physical damage concentrates. Bottom coil sections often show the worst fin damage on condensers from lawn equipment impacts, while top sections may have hail damage. Evaporator coils sometimes have fin damage from improper filter installation or overly aggressive previous cleaning attempts.
Post-Cleaning Testing and Verification
With coils clean and fins straightened, we reassemble all components and restore power to the system. We start the air conditioner and allow it to reach stable operation before taking performance measurements. Operating pressures and temperatures are recorded and compared to pre-cleaning baselines. Properly cleaned coils show measurably improved performance with lower condensing temperatures, more appropriate system pressures, and increased temperature drop across the evaporator coil.
We measure airflow at supply registers to verify cleaning has restored proper air movement through the system. Increased airflow is immediately noticeable and contributes significantly to improved comfort. We check for any leaks around coil access panels and verify all electrical connections remain secure after our work.
Documentation provided to customers includes before and after photographs, performance measurements demonstrating improvement, and recommendations for ongoing maintenance. We advise on optimal filter replacement schedules based on operating environment and explain how proper filtration reduces future coil contamination. For customers in particularly challenging environments with heavy dust or biological growth, we discuss preventive measures like upgraded filtration, UV light installation, or more frequent cleaning schedules that protect their investment and maintain peak system performance year-round.
