Openai/693ac84b-760c-8012-9228-3bba53f87139

This conversation was exported from ChatGPT

gpt-5-1

User: Why does smoke sometimes come out of aircon vents?

Why does smoke sometimes come out of aircon vents?

Assistant: Smoke-like stuff coming out of an aircon vent is usually not actually smoke.

Smoke-like stuff coming out of an aircon vent is usually not actually smoke. It almost always comes from harmless causes — but a few cases do need attention.

Here are the common reasons:

✅ 1. Cold air + humidity = fog (MOST COMMON)

If the air coming out of the vent is very cold and the room is very humid, the moisture in the air condenses into visible fog, which looks exactly like smoke.

Why it happens:

• The AC is cooling the air too fast.
• High room humidity (common in rainy/hot countries).
• Dirty filters reducing airflow, making the coil extra cold.

Fix: Clean the filter, increase fan speed, or reduce humidity.

✅ 2. Dirty filters or blocked airflow

If the airflow is restricted, the evaporator coil becomes too cold, causing excess condensation that turns into visible mist.

Fix: Clean or replace filters; check if the vents are blocked.

⚠️ 3. Refrigerant overcharge or freezing coils

A system that is overfilled with refrigerant or has a freezing evaporator coil may release mist or even tiny ice crystals that look like smoke.

Symptoms:

• AC not cooling well
• Ice build-up when you open the panel
• Hissing sounds

Fix: This needs a technician — don’t attempt refrigerant work yourself.

⚠️ 4. Actual smoke (rare)

Very rare, but possible if:

• The fan motor is overheating.
• Wiring is burning.
• There is a smell of burnt plastic or burnt dust.

If it smells like burning, turn the unit off immediately.

🧊 How to tell if it’s fog or smoke?

| Test | Fog (normal) | Smoke (problem) | | -------- | ----------------------------------- | --------------------------- | | Smell | No smell or slight “cold air” smell | Burning or electrical smell | | Color | White, light | Gray or darker | | Behavior | Disappears quickly | Lingers in the air |

If you want, tell me what your AC looks/smells like, and I can help diagnose the exact cause.