R asked in Home & GardenDo It Yourself (DIY) · 1 month ago

I have an attic fan and window in my attic, do I need to open the window when the fan is running up there? New home owner thanks for helping?

6 Answers

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  • Anonymous
    4 weeks ago

    Is there a stairway (passageway for air) leading from the house to the attic?  If yes, you can run the fan at night when it's cool out, with the attic window closed, but bedroom windows open and the cool air will come into the bedrooms and take any hot attic air out.  

    In daytime, if it's cool enough downstairs, close bedroom windows, close the door to the stairway to the attic and open the attic window and the fan will draw out the hot attic air which will keep the attic cooler which will not heat the rest of the house by preventing a hot ceiling.

  • 1 month ago

    An attic fan can do its job only if air can flow both into and out of the space. 

    DUHHHH! 

  • 1 month ago

    You didn't say if the attic is partially finished or not. If it is unfinished then there should be some vents either on the roof or the gable ends. Those are sufficient to exhaust any air that is pulled into the attic by the attic fan. 

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    If there are not vents then you need a open window in the attic or some other means of exhausting the air pulled in by the attic fan.

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    With the fan running you can crack open windows in various rooms to get the air moving. The result make not actually lower the temperature in the house very much but the moving air will make it feel cooler. 

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    We lived in one of the most humid places in the US (New Orleans) during WWII. We had an attic fan and it made a huge difference in the summer even if it did not make the house much cooler.

  • Anonymous
    1 month ago

    Two schools of thought on this - running the fan, window closed will draw air from the rest of the house if it is open to it, which may be a benefit, otherwise if you have a heat reservoir in the attic and you simply want to replace the air with cooler air (do this at night) you open the window as far away as possible from the fan outlet.

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  • 1 month ago

    When you run the attic fan, it has to draw air from somewhere.  Opening the window will allow the fan to suck fresh air into the attic. Assuming the outside air is cooler than the attic, this will cool the attic down and give the heat in the living space somewhere to go.

    Alternately, if there is an opening in the ceiling where air can pass easily, you may be able to use the attic fan as a "whole house" fan. To do this, you'd close the attic window and open downstairs windows.  Then run the fan in the early morning or evening when the outside temp is lower.  This will suck cool air into the entire house.  During the heat of the day, shut the house up to hold the cool air in. If the attic isn't open to the living space, you can do the same thing with a window fan. 

  • 1 month ago

    I run the attic fan and open windows at both ends of my attic.  The circulation helps keep the floors below cooler.

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