Air Conditioner Cleaning Guide | How Often to Clean - Full DIY Steps & Maintenance Tips

When summer arrives, nothing feels better than a cool breeze from your air conditioner. But have you noticed it’s not cooling as effectively, or that unpleasant odors are coming from the vents? These are warning signs that your AC needs to be cleaned. Air conditioner cleaning impacts not only cleanliness but also your health, electricity costs, and the lifespan of your unit.

This article gives you a professional rundown of the hidden risks, ideal cleaning schedule, easy DIY steps, and maintenance tips to help Hong Kong households improve indoor air quality, save on energy bills, and enjoy cleaner, healthier cooling.

Why Cleaning Your Air Conditioners Matters?

As an air conditioner operates, it draws in large volumes of air along with dust, pollen, and pet hair. Over time, these impurities accumulate inside the filters, evaporator coils, and air vents, leading to three major problems:

1. Poor Air Quality & Respiratory Issues

Dust, mold, and bacteria inside a dirty AC are blown out with every use. Prolonged exposure can trigger allergic rhinitis, asthma, and bronchitis, especially harmful to children, the elderly, and allergy sufferers. Studies even show that an unclean AC can harbor 60 times more bacteria than a toilet seat.

2. Reduced Efficiency & Higher Electricity Bills

If you feel the air isn’t cold enough or hear unusual noises, performance has likely dropped. When coils and drains are clogged with dust, the compressor must work harder to reach the desired temperature—consuming more power and driving up your energy bill.

3. Shortened Lifespan with Odor, Water Leakage or Breakdowns

The filter and drip tray remain moist and warm—ideal conditions for bacteria and mold growth, which cause musty or sour smells when switched on. A clogged drain pipe can lead to water leakage or component damage. Proper, regular cleaning helps your AC last its full 8–12 years instead of needing replacement or repair every few years.

How Often Should You Clean Air-Conditioners?

Cleaning frequency depends on the unit type, usage, and environment.

  • Household split or window units: Deep clean at least once a year, preferably before or after the cooling season.
  • Homes with elderly people, infants, pets, or near busy roads or construction sites: Every six months.
  • Offices, restaurants, or commercial spaces: Every 3–6 months, with professional maintenance.

If cooling is weak, odor appears, or water drips, arrange cleaning immediately to prevent further damage.

Air-Conditioner DIY Cleaning Steps (Split or Window AC)

1. Power Off

Unplug the unit or switch off the circuit breaker to prevent electric shock.

2. Clean the Filter

Remove the cover and filter, rinse with clean water, and dry thoroughly. For heavier dirt, soak in a mild detergent or baking soda solution.

3. Clean the Evaporator and Casing

Use a brush or vacuum cleaner to remove dust. Spray with a specialized foam cleaner and let it sit for 10–20 minutes, then rinse with clean water and ensure wastewater drains away properly.

4. Dry & reassemble

After all parts are completely dry, reinstall them. Run the fan mode for about 20 minutes to remove moisture and prevent musty odors.

This process is suitable for basic maintenance. For deeper internal cleaning (fan drum, drainage system, or cooling coils components), professional service is recommended.

DIY vs. Professional Air-Conditioner Cleaning

Item DIY Cleaning Professional Cleaning Service
Cost HK$100–300 (for cleaning supplies) HK$900–1200 per unit
Cleaning Depth Outer casing, filter, visible coil surface Full disassembly and deep internal cleaning of coil, fan, drainage, condenser
Effectiveness Limited on stubborn grime, higher risk of damage Industrial-grade tools and safe, enzymatic cleaners ensure complete mold and bacteria removal
Time Required 3–5 hours for first-time users 2–3 hours for a 3-part split system by professionals

If your air conditioner shows obvious issues—such as weaker airflow, a musty smell, or more than a year since the last deep clean—it is recommended to seek professional AC cleaning service from Johnson Group.

Johnson Group Professional Air-Conditioner Cleaning Service

We follow a Standardized 7‑Step Deep Cleaning Process, with very step is executed with precision and care:

1. Inspection

We begin by inspecting the unit’s body and performance to identify cooling efficiency issues, odor sources, and the presence of mold or dust buildup, ensuring targeted cleaning in subsequent steps.

2. Filter Removal and Cleaning

As filters are prime hiding spots for dust and bacteria, we use a medical‑grade Miele allergy vacuum to thoroughly remove mold, suspended particles, and allergens from the cover, filter, cooling coil, and fan. This significantly reduces IgE (Immunoglobulin E) triggers and improves overall air quality.

3. Deep Cleaning with AerisGuard™ Coil Cleaner

We apply a pH‑neutral enzyme formula to break down biofilm, bacteria, and mold on cooling coils and fans. This process restores cooling performance without damaging metal surfaces.

4. High‑Temperature Sanitization

Using a professional‑grade Karcher® steam cleaner, we sanitize coils, fans, and vents at high temperature, effectively eliminating mold, bacteria, stubborn dirt, and odor while enhancing airflow and energy efficiency.

5. Comprehensive Disinfection with SmellGREEN® Natural Sanitizer

We use U.S. EPA‑approved plant‑based disinfectant to sanitize covers, filters, and fans. It eliminates 99.99% of bacteria and viruses and is completely safe for children and pets.

6. Application of AerisGuard™ Anti‑Mold Coating

A U.S. EPA‑approved long‑lasting antimicrobial coating is applied to the cooling coil, continuously releasing antibacterial agents to prevent future mold and bacterial growth for up to 12 months.

7. Drying, Reassembly, and Final Testing

After cleaning, all components are carefully reassembled and tested to ensure optimal operation.

With over 70 years of professional experience, we are a trusted industry leader using enzyme-based, pH-neutral, non-corrosive products—safe for sensitive users. Their comprehensive cleaning coverage and consistent results have earned strong customer trust. Choosing Johnson Group means choosing quality, safety, and peace of mind.

Johnson Group Air-Conditoner Cleaning Service
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Air-Conditioner Maintenance Tips

  • Clean dust filters every 1–2 months.
  • Run fan mode for 20–30 minutes before cooling to keep interior dry.
  • Keep vents unobstructed.
  • Check the drainage pipe regularly to prevent leaks.
  • Avoid frequent on-off cycling to extend lifespan.
  • If odor or noise occurs, contact a technician promptly.

Air-Conditioner Cleaning FAQs

Air-Conditioner Cleaning typically takes 1 to 3 hours per household unit, depending on the model and the level of cleaning required.

DIY cleaning works well for surface maintenance—similar to daily brushing. However, mold and bacteria often build up deep between the coils, like plaque between teeth. For a thorough clean, it’s best to schedule professional servicing once or twice a year, much like regular dental scaling.

Normally, no. Air conditioners are sealed systems, and the refrigerant does not run out over time. If cooling performance drops, it’s usually due to clogged filters or coils rather than low refrigerant levels.

Wait until the unit is completely dry—typically 1 hour. You can use a fan to speed up drying, but never switch on the air conditioner while it’s still damp to prevent short circuits.

When performed by trained professionals, cleaning carries minimal risk. For DIY cleaning, handle parts gently, use suitable detergents, and keep water away from electrical components.