For an evaporative air conditioner to work effectively, some windows or outside doors must be open, or some other form of ventilation provided. This is to allow the hot air to escape outside of the building. The best approach is to open the windows or outside doors that are the furthest away from the air conditioning vents or ducts. In the rooms with air conditioning vents, try to have an exhaust area of open window (or door) that is about twice the size of the vent opening. Note: when it’s humid and the air is very moist, evaporation levels are lower. This means that the cooling effect is reduced. In some situations, it may help to switch the air conditioner to “ventilation” mode and run the fan on a high speed. If you have tried all of the above and still feel your air conditioner is not working effectively, your air conditioner may need to be serviced.