Attic Fan Energy Usage

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Attic fan energy usage.

However if your attic has blocked soffit vents and is not well sealed from the rest of the house attic fans will suck cool conditioned air up out of the house and into the attic. The attic cools and the attic fan goes off. This type of system blows hot air out of the attic but it can have a negative effect. Attic fans are intended to cool hot attics by drawing in cooler outside air from attic vents soffit and gable and pushing hot air to the outside.

Similarly painting the roof white causes the roof to cool. The cooler roof radiates and conducts less to the attic. Attic ventilation will usually need to be increased to exhaust the fan s air outdoors. The a c usage goes down.

And i agree with the additional energy costs but my attic fan is a 1500 cfm 40 watts. A whole house uses 80 to 300 watts of energy that s around 15 less energy compared to an air conditioner which uses up to 3000watts of energy. Sunshine is reflected instead of heating the roof. This will mean around 0 02 to run per hour depending on electricity costs.

You ll need 2 to 4 times the normal area of attic vents or about one square foot of net free area for every 750 cubic feet per minute of fan capacity. The benefit from lowering temperatures in the attic and thus reducing heat gain from the attic into the house is usually off set by the electricity use by the fan and the increase in air leakage. How much electricity does a ceiling fan use. Ceiling fans tend to use a similar level of electricity as a tower fan.

Many users however claim an attic fan is a money saver but they do not offer documented proof of the savings. On one hand the national renewable energy laboratory said attic ventilation reduces attic temperature 10 to 25 degrees and slows the transfer of heat into the living space on the other the florida solar energy center university of central florida found that attics with nominal natural ventilation and r 19 ceiling insulation do not need powered vent fans. 100w would be a reasonable estimation but obviously this varies depending on the model you own. If a 100 attic fan which consumes little electricity compared with an ac unit and contains far less embodied energy can be part of a plan to reduce heat gain there may be a significant energy and environmental benefit compared to the ac option.

The average attic fan draws less than 300 watts making it seem like an energy efficient home improvement but some professionals in the field claim that attic fans are not a cost saving investment. The whole house fan has a significant role in preventing the heat piled up in the attic from spreading to the living room or the entire house at large.