Do We Need An Attic Fan

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Do we need an attic fan.

In a properly designed passive system air enters through the soffit. 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. Most homeowner s that are building homes and renovating older homes have found that a better choice for ventilating the attic space is through the use an attic fan. 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.

Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation. The ventilation that controls moisture from condensation and regulates the temperature in your attic relies on air circulation. Soffits gable vents without fans and rafter vents are passive ventilation systems to keep your roof and attic healthy. This prevents hot air from seeping into your home and driving up the temperature in the living space which reduces the load on your air conditioner.

Your home s roof and attic was most likely designed with just the right amount of fresh air it needs. Adding roof ridge vents can reduce summer air conditioning costs prevent roof mildew and rot and keep your roof in better shape longer. Because what happens is attic fans are so strong that they actually reach down into the conditioned space of your house and they do that by using the wall cavities and where the outlets and pipes come through the walls as places where they draw air from the inside of your house it. Whole house fans need windows and doors open and attic fans need lots of soffit vents to suck.

Ok i would definitely not recommend an attic fan. Purchasing an electric or solar attic fan may not provide the savings that homeowners expect. Attic ventilation fans help cool air your attic by pushing out the stifling hot air from inside the attic and bringing in cool air from outside. That said air resistance and interference such as vent grates reduces the area of true ventilation.

If an attic fan is properly installed it will act as an air circulator. In other words the entire vent opening doesn t count as vented space. For both fans to work well they need large exhaust openings in the roof for the moving air to exit. Powered attic ventilators or attic fans just as they sound are designed explicitly for placing or installing in the attics.

The main work of an attic fan is to regulate the heat level of the attic by removing hot air out of the attic and pushing it outside providing needed ventilation.