Don't waste your money. The building codes today require that new homes be built very air tightly. The problem is that due to an oversight, the requirement that they also be mechanically ventilated with fresh air got left out of the code until this year. So, you likely just need to bring in some fresh air. In your humid climate try an Energy Recovery Ventilator (ERV) or an AirCycler unit. The Florida Solar Energy Center web site has good information relevant to your location on the topic of home ventilation.