DIY vs Professional Chemical Wash: What You Need to Know About Home Aircon Cleaning
Many homeowners try to save money by cleaning their aircons themselves. You can buy “Aircon Cleaner” spray cans from local supermarkets like NTUC FairPrice or hardware stores for about $15 to $25. The packaging promises a “professional chemical clean” in just 10 minutes. But do these products really work?
Based on our experience servicing homes across Singapore, we have seen many units that were recently cleaned with DIY sprays. When we open them up for professional servicing, we often find problems that the spray did not solve.
The “Surface Clean” Problem
When our technicians dismantle units that have been DIY-cleaned, we commonly find:
- Mold is still growing behind the fan roller and on the back of the drainage tray. These are areas the spray cannot reach.
- Chemical residue on the aluminum fins (cooling coils) because the DIY chemical was not rinsed off properly with water.
- Water leakage problems within weeks of DIY cleaning, caused by dislodged dirt clogging the drainage pipe.
The Hidden Dangers of DIY Cleaning
1. You Cannot Reach the Critical “Back” Areas
DIY sprays only clean the front of the cooling fins (evaporator coil). They do not reach the back tray or the fan blower.
When we dismantle units cleaned by homeowners, the front looks shiny and smells like lemon. But when we take out the fan blower, the back is full of black jelly and mold. That mold spores blow right into your face while you sleep, causing morning sinus.
2. Chemical Residue Corrodes Your Unit (The “Leaving It On” Mistake)
Professional Chemical Wash involves using industrial-grade alkaline or acid-based chemicals to dissolve dirt. Crucially, professionals use high-pressure water jets to completely flush these chemicals out after 10-15 minutes.
Most DIY cans are “no-rinse” or “leave-on” foams. You spray it on and let the condensation wash it away. The problem? In Singapore’s humidity, the chemical often dries up on the fins before it drains. This dried chemical residue is corrosive. Over time, it eats into the thin aluminum fins and copper pipes, leading to gas leaks that cannot be repaired—requiring you to replace the entire fancoil unit (costing $400-$600).
3. Health Risks: What Are You Breathing?
Mold commonly grows in poorly cleaned aircon units in Singapore’s humid climate. Common types of mold like Aspergillus, Cladosporium, and Penicillium are known allergens that can trigger asthma attacks, chronic coughing, and sinus allergies.
A professional wash is the only way to remove 99.9% of these contaminants because we dismantle the unit to reach every dark corner where mold hides.
Detailed Comparison: DIY vs. Professional Service
| Feature | DIY Spray Can | Professional Chemical Wash |
| Cost | $15 – $25 (per can) | $80 – $150 (depends on unit & type) |
| Time & Effort | 30 mins (Messy, DIY effort) | 45-60 mins (Sit back & relax) |
| Depth of Clean | Surface only (10-20% coverage) | Deep internal clean (100% coverage) |
| Mold Removal | Ineffective (Masks smell only) | Highly Effective (Kills bacteria) |
| Risk of Damage | High (Corrosion, PCB damage) | Low (Professional handling) |
| Drainage Cleaning | Cannot flush drainage pipe | High-pressure vacuum/flush included |
| Warranty | None (You are responsible) | Yes (30-90 days Water leak warranty) |
When Should You Call a Pro?
We are not saying you should never touch your aircon. DIY cleaning of the plastic filters and outer casing is excellent for weekly or bi-weekly maintenance. It keeps surface dust away.
However, if you encounter any of the following, a spray can will NOT help and might make things worse:
- You haven’t had a professional clean in over 6 months.
- You suspect mold (black spots on the fan blades).
- The unit is leaking water (spray cans cannot clear drainage chokes).
- The airflow is weak (internal blockage).
If your unit is very old (5+ years) or extremely dirty, even a standard Chemical Wash might not be enough. In those cases, we recommend a Chemical Overhaul, where we take the unit down from the wall completely for a factory-level reset.
Protect Your Health and Your Aircon
Your aircon is an expensive appliance. Don’t risk damaging it or breathing in mold just to save $50. Let our NEA-trained experts handle the deep cleaning safely and effectively.