An air conditioner will not enhance the effect of a humidifier. If you would use an air conditioner normally (>25 °C), the humidity will be at a normal level and a humidifier is less likely to be needed.

Do you have plants? Then it is advantageous to place the humidifier between or against the plants. The moisture droplets then settle directly on the leaves and potting soil, which can help the plant absorb moisture.