Aircond Chemical Wash for Smelly Unit in Shah Alam Terrace After Flood

The Customer's Situation

Encik Roslan and his family live in a single-storey terrace house in Section 7, Shah Alam. During the heavy monsoon rains in December 2025, their area experienced flash flooding. While the water level in their house only reached about 6 inches — enough to damage some furniture but not catastrophic — the aftermath left a much bigger problem than they expected.

About two weeks after the floodwaters receded, Encik Roslan noticed both aircond units in the house (Panasonic 1.5HP in the master bedroom and 1.0HP in the second bedroom) were producing a terrible musty, swampy smell when turned on. The smell was so bad that his daughter, 8-year-old Aisyah, started coughing every night and complaining of itchy eyes.

Puan Zaiton, Encik Roslan's wife, had tried cleaning the filters herself — washing them with Dettol and letting them dry in the sun. It helped slightly for a day or two, but the smell always came back. That's when they decided to call us.

Why Flooding Causes Severe Aircond Mould

When a house floods, even briefly, the indoor humidity skyrockets and stays elevated for weeks afterward. Walls, floors, and furniture absorb water and slowly release moisture into the air. This sustained high humidity — often 85-95% — creates the perfect environment for rapid mould colonisation.

The aircond unit, with its cold, wet evaporator coil, becomes ground zero for mould growth. In normal conditions, mould builds up gradually over months. After flooding, the same level of contamination can happen in just 2-3 weeks.

Encik Roslan's units had only been serviced 4 months before the flood. Under normal circumstances, they wouldn't have needed attention for another 2 months. But the flood changed everything.

Our Approach: Full Chemical Wash

Our technician Iskandar assessed both units and immediately recommended a full chemical wash rather than standard cleaning. The mould contamination was too severe for water pressure alone to handle. Here's what he found and did:

Master Bedroom Unit (1.5HP)

When Iskandar removed the front panel and exposed the evaporator coil, the severity was immediately apparent. The normally silver aluminium fins had a visible black-green coating of mould across about 80% of the surface. The blower fan blades were coated in a dark, sticky biofilm. The drain pan had a thick layer of brownish slime.

The smell hit you the moment the panel came off — a concentrated version of what was being blown into the bedroom every night while the family slept.

The runoff water from the cleaning was dark brown — almost black — for the first few litres. Encik Roslan watched the process and was visibly shocked. "All that was in the aircond? No wonder Aisyah was coughing," he said.

Second Bedroom Unit (1.0HP)

The smaller unit had similar mould contamination, though slightly less severe since the second bedroom had been closed off during the flood cleanup period and wasn't used as frequently. Iskandar performed the same full chemical wash process.

Results

• Smell: Completely eliminated from both units. Air coming from the vents smelled clean and fresh immediately after the wash.
• Cooling performance: Both units noticeably colder — the mould layer had been insulating the coil and reducing heat exchange. Master bedroom unit outlet temperature improved from 16°C to 12°C.
• Aisyah's symptoms: Puan Zaiton reported that her daughter's coughing stopped within 2 days and the eye irritation cleared up within a week.
• Airflow: Stronger and more even from both units — the clogged coil fins were now clear and allowing full air passage.

Pricing

• Chemical wash for 1.5HP Panasonic (master bedroom): RM200
• Chemical wash for 1.0HP Panasonic (second bedroom): RM200
• Total: RM400

Post-Flood Aircond Advice

If your home has experienced any level of flooding, we strongly recommend:

For really severe cases where mould has spread deep into the unit, a chemical wash may need to be upgraded to a full chemical overhaul involving complete disassembly of the indoor unit.

1. Get your aircond chemically washed within 2-3 weeks after the flood. Don't wait for the smell to develop — by then, the mould is already well-established.
2. Run your aircond in "dry" mode as much as possible in the weeks following a flood. This helps dehumidify the indoor air and reduces the moisture available for mould growth.
3. Keep windows open during the day (when practical) to ventilate and dry out the house.
4. Consider a follow-up clean 2-3 months later. Residual moisture in walls and furniture may continue feeding mould growth for several months after a flood.

Understanding why your aircond smells and how to prevent it can help you maintain a healthy indoor environment, especially in Malaysia's humid climate.

Customer Feedback

"After the flood, I was focused on fixing the floor and furniture. I didn't think about the aircond until the smell started. Iskandar showed us the mould inside the unit — it was really bad. After the chemical wash, the air is clean, the bedroom smells fresh, and most importantly my daughter stopped coughing. Thank you so much."

— Encik Roslan, Shah Alam