Dehumidifiers are either portable or whole house units that remove excess moisture from the surrounding air. During very warm weather and in areas of high humidity, removing this moisture can improve the overall comfort level. Dehumidifier units are sold online and in many hardware or home retail stores and may also reduce condensation and allergies caused by damp air for some users. Dehumidifiers can range in price from $30 for a portable dehumidifier to $2,000 or more for a whole house unit as of June 2011.
You can find small to medium-size portable fans, which can be moved from room to room within a home. Some portable fans are oscillating to move air throughout an entire room, and some portable fans are tower style. These fans can be purchased at many home retail stores, department stores, hardware stores and online and range in price from approximately $10 on up.
Attic fans are designed to pull outside air into the home through the attic vents and force the hot air outside. Since warm air rises, operating an attic fan can help remove some of the hot air in a home and replace it with cooler air. Attic fans are run for short periods, typically during the day. Attic fans require professional installation and cost approximately $75 to $300.
Whole house fans are also commonly installed in the attic and are usually used at night. Cold night air is brought into the home and warm air pulled up and out through the vents and roof. A whole house fan can cost between $150 and $350, but installation costs may bring the cost to more than $1,000.