Ceiling Cassette Coil Breakdown — Sticky Residue From Insulation Failure

What Was Happening

Customer reported:

• Weak cooling, especially during longer runs

• Uneven airflow despite recent surface cleaning

• Occasional chemical-like smell when system was on

Multiple past servicings had skipped dismantling — problem remained unsolved.

What We Found

Coil Breakdown & Contamination

• Internal insulation near the coil had degraded into a sticky, jelly-like substance

• Breakdown was concentrated at coil bends, likely due to long-term heat exposure

• The jelly layer had trapped fine dust and grease, choking heat exchange

• Blower assemblies showed signs of residue re-circulation, affecting airflow

Sticky coil residue removed from ceiling cassette during overhaul

What We Did

Full Dismantle & Internal Overhaul

• Fully dismantled the ceiling cassette unit

• Removed all degraded sealant and insulation manually

• Chemically flushed blower wheels, coil face, and drain line

• Reinsulated affected areas with heat-rated wrap

• Reassembled, airflow rebalanced, and cooling tested

The Result

• Cooling performance restored

• Even airflow across all vents

• Odour eliminated

• Coil surface now clean and insulated correctly

What Could’ve Gone Wrong

• Sticky insulation would continue trapping dust, quietly choking heat exchange

• Cooling would degrade further, forcing the system to overwork

• Fan imbalance could emerge from residue buildup on the blower

• Electrical components near the affected area could be exposed to moisture or residue — raising risk of shorting or failure

What This Case Shows

Surface cleaning doesn’t touch this.

This wasn’t dust. It was long-term insulation breakdown.

If your ceiling cassette has never been dismantled — it’s never really been checked.

Only a full internal inspection exposes faults like this.