The unit runs but provides very little or no cooling; air from the outlet is only slightly cooler than the room.

Safety first: Unplug before cleaning coils or filters.

• 1. Clean filters and coils: Wash filters and vacuum both the evaporator (front) and condenser (rear) coils. Use a soft brush to avoid bending fins.
• 2. Check exhaust (portable units): Ensure the exhaust hose is properly connected, not kinked, and venting outside. Seal gaps around the window kit to prevent hot air from re-entering the room.
• 3. Room conditions: Close doors and windows. Reduce heat sources (ovens, direct sun) and ensure the room size is within the unit's rated capacity.
• 4. Measure temperature drop: After 15 minutes of operation, measure the air temperature at the intake and outlet. A healthy system typically shows an 8–12°C drop. If much less, refrigerant or internal issues may exist.
• 5. Technician service: If cleaning and setup are correct but cooling remains weak, a technician should check the refrigerant charge and system pressures.