Where is the mould forming ?
Underfloor ventilation would be a good starting point but if it not a serious problem I would be trying to increase ventilation to the area, use a de-humidifier (have found this makes the biggest difference) or increasing natural light.
I also heard bleach doesn't work and have used plain old white vinegar sucessfully in the past.
Would say evaporative cooler would definitely add to the mould issue - need drier air, not more moist air.