For Reference: Dehumidifiers come in two flavors.
1) Cool the air down below dew point, drains some water off the cold coils as it's at 100% humidity, air comes out with less moisture. Some of these reject the heat back into the space (Think a home unit, outside and inside, in the same box) some reject it outside (home unit, with outside connection to reject heat to) Either way, this is about as efficient as running your air conditioning, down to being less efficient if it rejects heat that you have to remove. These dehumidification units usually find their niche around basements, as the air is already chilly, but it's moist.
2) Chemical Dehumidification: Think Damp-rid. It absorbs moisture as the material is dryer than the air at the temperature it is at, equalizes eventually, then you can sometimes remove the material, heat it up, and it releases the moisture to the atmosphere. These are usually done in emergency situations. a ton of water got where water shouldn't be.
So if you're thinking of a dehumidification unit for your (south-east) house, it may make sense for just a window unit, or a "mobile" room AC unit, instead, as you will likely get use out of the cold air it provides. and remember, a smaller unit is better for dehumidification! don't let that sucker turn off!