Results 1 to 11 of 11
  1. #1
    John Stephenson's Avatar
    John Stephenson Guest

  2. #2
    Join Date
    Mar 2007
    Location
    Spring Hill (Nashville), TN
    Posts
    5,829

    Default Re: Solar powered air vent

    I don't see a problem with it. But then that is the first solar powered attic power vent I have seen. I might make note of it and tell my client that this is an unconventional design and unconventional designs tend to perform in unconventional ways.

    Scott Patterson, ACI
    Spring Hill, TN
    www.traceinspections.com

  3. #3
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    25,313

    Default Re: Solar powered air vent

    Also write up that operating an attic exhaust fan will depressurize the attic, which in turn will depressurize the house, which in turn draws in un-conditioned outdoor air to replace the conditioned air which was drawn out, which brings in excess moisture - which must be removed by the a/c running longer.

    Making the probable net effect of operating an attic exhaust fan a net negative, i.e., net energy loss, even though 'the fan' "costs nothing to operate" because it is solar powered.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  4. #4
    Join Date
    Mar 2007
    Location
    Santa Rosa, CA
    Posts
    2,286

    Default Re: Solar powered air vent

    My experience is that the solar powered fans operate at a much lower air exchange rate than the ac gable or roof fans. The are very quiet and effective in venting the attic. Jerry has a point, but a cooler attic is going to result in a cooler house. It would be interesting to see a real study that analyzes the trade offs.

    Department of Redundancy Department
    http://www.FullCircleInspect.com/

  5. #5
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    25,313

    Default Re: Solar powered air vent

    Quote Originally Posted by John Stephenson View Post
    Also write up that operating an attic exhaust fan will depressurize the attic, which in turn will depressurize the house, which in turn draws in un-conditioned outdoor air to replace the conditioned air which was drawn out, which brings in excess moisture - which must be removed by the a/c running longer.


    Well I never thought of that...is that true to all power fans? Do you have "data" to support your conclusion?
    Dr. Joe L.

    He explained it in one of his classes I attended.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  6. #6
    David Banks's Avatar
    David Banks Guest

    Default Re: Solar powered air vent

    and who is Dr Joe L?
    Blasphemy!


  7. #7
    Join Date
    Mar 2007
    Location
    Spring Hill (Nashville), TN
    Posts
    5,829

    Default Re: Solar powered air vent

    Quote Originally Posted by David Banks View Post
    and who is Dr Joe L?
    Blasphemy!
    Building Science Corporation

    Keep in mind that some folks agree with his opinions and others do not.

    In a conventional attic with conventional asphalt fiberglass shingles on the roof in the Southern or Western part of the country, I can't see not having ventilation in the attic to relieve the heat that builds up during the day.

    Scott Patterson, ACI
    Spring Hill, TN
    www.traceinspections.com

  8. #8
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    25,313

    Default Re: Solar powered air vent

    Quote Originally Posted by Scott Patterson View Post
    In a conventional attic with conventional asphalt fiberglass shingles on the roof in the Southern or Western part of the country, I can't see not having ventilation in the attic to relieve the heat that builds up during the day.
    In my house down in South Florida, with a conventional attic, I installed an attic exhaust fan like the one in that photo (except not solar powered), then, a few years later attended a few of his classes, went back and disconnected it.

    I believe that the house was much more comfortable feeling with that exhaust fan not operating than it was with it operating - the house was a 1974 house, on the beginning of the tighter and better insulated upward curve of building construction, and there was enough air leaks and loss from the house into the attic to make a difference, and standard non-energy efficient windows, which allowed outdoor air in to make up for that air lost to the attic. In South Florida, that make up air was very humid air.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  9. #9
    Join Date
    Mar 2007
    Location
    Dallas, Texas
    Posts
    4,112

    Default Re: Solar powered air vent

    I think one key to remember on attic ventilation is that in order for it to work effectively there must be an inlet (soffit) and an outlet (roof) and they must be balanced.
    Too much roof vent in relation to the soffit vent and the attic will be mildly depressurized even without a powered exhaust vent fan if on a sloped roof application.
    Conversely, IMO if there is enough soffit vent even with a powered exhaust fan there would be little depressurization.
    I can agree with Dr. Joe when we are talking new construction and unvented attics, but existing construction that was planned to have attic ventilation needs ventilation.
    I am NOT a proponent of powered attic vents, but if you use them, then provide enough inlet vents to avoid depressurizing the attic.
    I would recommend anyone to attend one of his classes if you ever get the chance, he is a very knowledgeable guy and entertaining to boot.

    Jim Luttrall
    www.MrInspector.net
    Dallas, Texas

  10. #10
    Join Date
    Mar 2007
    Location
    Corpus Christi, TX
    Posts
    613

    Default Re: Solar powered air vent

    I cannot think of any other person who has had me in a room for 16 hours (two seminars) and I didn't want to run away. The only thing I've ever heard him say that I didn't like was that all houses in our climate should have white concrete tile roofs. I agreed with his logic, I just am not a fan of how they look and I dread the day when the big one hits and all these millions of two pounds missles are flying everywhere.

    The only reason some people get lost in thought is because it's unfamiliar territory.
    - Paul Fix

  11. #11
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    25,313

    Default Re: Solar powered air vent

    Quote Originally Posted by Thom Walker View Post
    I dread the day when the big one hits and all these millions of two pounds missles are flying everywhere.
    That's where wind borne debris (impact) protection for windows comes into play.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •