Why Coil Cleaning in Window AC Units Is More Than Just a Quick Wipe

Most people don’t think about what’s happening inside their window air conditioner—until it stops cooling properly, starts blowing dust, or smells musty. By the time you realize the unit needs cleaning, the coils are usually caked in grime, and a surface wipe simply won’t cut it.

Let’s break down why coil cleaning in window AC units is essential, what the process involves, and why it’s often best done outdoors by professionals.

What Are AC Coils and Why Do They Matter?

Window AC units have two main coils:

• The evaporator coil, located near the front (interior side), absorbs heat from your room.

• The condenser coil, located in the rear (exterior side), releases that heat outside.

  
  

When coils are covered in dust, pet hair, or mold, airflow is restricted and heat exchange is compromised. That means:

• Poor cooling performance

• Higher energy bills

• Potential system freeze-up

• Moldy, musty air blowing into your space

Coil Cleaning Isn’t Just a Spray and Go

Many DIY tutorials suggest using a can of foam cleaner and a vacuum. But in reality, proper coil cleaning requires dismantling the unit, especially if the buildup is significant.

Here’s what the real process often looks like:

1. Power Disconnect and Removal from the Window

   • Safety comes first. We unplug the unit, then carefully remove it from the window casing, often with two techs to avoid injury or damage.

     
     

2. Full Casing and Chassis Disassembly

   • The outer shell is removed to expose the internal components. That includes the blower wheel, coils, drain tray, and fan motor.

     
     

     

     Disassembly of a window unit with Dezier Air

     
     

3. Visual Inspection

   • We check for mold, caked-on debris, bent fins, and signs of long-term neglect.

     
     

4. Chemical Coil Cleaning

   • A foaming coil cleaner is applied and allowed to soak. This breaks down grease, pollen, bio-growth, and fine particulates.

   • In most cases, the coils need a high-pressure rinse—which is why we recommend cleaning window units outside, where chemicals can be flushed away properly and safely.

     
     

5. Blower Wheel and Drain Tray Cleaning

   • Dust and mold from the blower often recirculate in the air, so we thoroughly scrub and rinse it along with the drain pan.

     
     

6. Reassembly, Dry Time, and Function Check

   • Once fully rinsed, the unit is dried, reassembled, and tested for proper operation—including checking air temp, fan speed, and drainage.

Why You Should Avoid Indoor Coil Cleaning

Cleaning coils in a window unit in NYC

While it may seem easier to clean the coils indoors, coil cleaner chemicals are not safe to use in enclosed spaces. They contain surfactants, degreasers, and sometimes acid-based agents that can irritate lungs, damage flooring, or stain nearby surfaces.

Also, rinsing a unit indoors poses a risk of electrical damage or water leakage into your walls and flooring.

Benefits of Deep Coil Cleaning

• Restores cooling capacity

• Improves airflow and energy efficiency

• Removes allergens and mold from the system

• Extends the lifespan of the unit

• Prevents future breakdowns due to overheating or water damage

Window units often work hard for years without maintenance. But when dust, mold, and gunk build up on the coils, they can’t perform—no matter how much you run them. If your window AC smells bad, runs constantly, or doesn’t cool like it used to, a full coil cleaning may be the only real fix.

At Dezier Air, we offer professional window AC coil cleaning services that go beyond a surface wipe. We disassemble, clean, and recondition your unit so it works like new—all while protecting your home from chemical exposure and mess.