The air conditioning needs of the muggy, humid southeast summers require different methods for sizing and equipment selection than the hot, arid summers in the southwest. In certain parts of the country, the quality of electric power distribution causes brown-outs or worse. These areas often require special added equipment to deal with certain power sags. Some areas of the country have other unique problems like airborne pollen or pollution which can cause respiratory issues. Coastal regions near the ocean can have special problems with corrosion from salt spray. If you have just moved to a new area and are not sure about what unique issues your region faces you should consult with a contractor who can explain the best ways to deal with these problems before purchasing your new AC system.