If you live in a state with a perpetually wet basement like me, you're probably running a dehumidifier year-round. Ours sucks the moisture out of our always-wet walls and drains it into the sump pump.
If you're luckier than me, you may only use a dehumidifier for humid summer days and are dragging yours out of storage right about now. If you have an older model, you may want to consider upgrading to an Energy Star qualified one. It removes the same amount of moisture as a unit of the same size but uses 10 to 20 percent less energy, which could actually power your refrigerator for six months. Visit Energy Star's page on dehumidifiers for more information as well as a list of approved models.
And live in Florida and run your air conditioner all year to remove the humidity from the house. One thing you fail to mention is that removing this moisture from the walls of the basement discourages mold growth because one thing mold needs to grow is water. So installing a dehum may actually improve your allergy problems.