Fans are usually more economical than air conditioners.
In some areas of the country where summers are scorching, air conditioning is a much-loved amenity in homes. However, it is costly both in terms of energy used and your electricity bill. Fans are a much cheaper solution not only upfront but also to run on a regular basis. The surprise comes in how much cheaper running fans are than running the air conditioner.
Wattage
While it seems counterintuitive that running eight fans continuously is less costly than running a central air conditioner for the same amount of time, it is true. Floor fans use up to 100 watts per hour each, while ceiling fans use from 15 to 95 watts per hour. A standard 2.5-ton central air-conditioning unit used to cool 1,200- to 1,500-square-foot homes uses 3,500 watts per hour. Even with eight fans running at maximum speeds, you would be using only a maximum of 800 watts, less than a quarter of the energy used to power a central air-conditioning unit. A single medium window air-conditioning unit, however, uses only about 900 watts an hour, but it only cools a single room; using the eight fans would still use less energy.
Cost Per Watt
If you pay $0.15 per kilowatt (1,000 watts) used per hour, running eight fans at maximum speeds for four hours a day, seven days a week, for a month would cost $14.40. However, running the central air conditioner instead for the same amount of time would cost you $63 in a month. To run a single medium window air-conditioning unit, the cost would be $16.20.
Strategic Use
Fans only work when someone is in the room, despite popular assumptions to the contrary. The airflow created by fans uses people's natural cooling system, sweat, to cool them off. As a person sweats, the perspiration evaporates and cools the skin. Fans speed up this process by making the sweat evaporate faster, thus cooling you down faster. If you want to use fans properly, direct them at people in the room. Also, check that your ceiling fan is in the summer mode so the air circulation is being pushed down instead of up.
Combination Method
In areas with very hot summers, you may benefit from using the combination method. Using fans in the cool of the early morning, late evening and overnight will keep you comfortable. Keep the house closed up during the heat of the day, also using fans to keep cool. Once the home becomes too hot, use the air conditioner to cool the house for an hour or two before turning it off and relying on fans. This method will keep both your energy use and electricity bill low while still providing a more comfortable temperature in your home.
Tags: air-conditioning unit, eight fans, watts hour, amount time, central air-conditioning, central air-conditioning unit