roof vents to cut cooling costs

Discussion in 'Roofing and Siding' started by sharon, Sep 26, 2005.

  1. Sep 26, 2005 #1

    sharon

    sharon

    sharon

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    Are the vents you can install in your roof really worth it? I mean do they really make a difference in your cooling costs? If so, which ones are the best?

    sharon
     
  2. Oct 12, 2005 #2

    Bill

    Bill

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    YES THEY ARE NECESSARY!!! When it gets hot outside the air comes in from your soffit and rises under your roof sheathing. This warm air goes out the vents thus your attic space is cooled. This helps in the winter also by removing water vapor from your attic area. The condensation will cause your insulation to be compromized. In very cold area like Minnesota etal where Ice dams are common the venting along with insulation minimize the ice dam.
     
  3. Oct 12, 2005 #3

    FirTrader

    FirTrader

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    It also lets your shingles live about 10 years longer. Shingles fail much faster if there's no air-space below the sheeting on the roof to provide some cooling.
     
  4. Mar 1, 2006 #4

    glennjanie

    glennjanie

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    I reccommend the use of a continous ridge vent and continous eave vents; its called the "ice house effect" which allows air to move up the decking from bottom to top of the whole roof. A rule of thumb is to calculate the sqrare feet of attic space and use one square inch of ventilation for each square foot of space. Cardinal law!!!! Do not cover vents in the winter time; it causes sweating in the attic--then rotting--and poor insulation. If your home is properly insulated and the roof properly vented yours will be the last in the neighborhood to melt the snow off.
     
  5. Mar 2, 2006 #5

    mickmar

    mickmar

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    sharon, the more vents you have the better. You want the temperature in your attic the same as the outdoor temperature. The only ones that I would not install are the whirlybird ones you see. They can develop a squeeck and drive you nuts. Talk to a good insulation company, venting is just as important as insulation. Mick
     
  6. Aug 28, 2006 #6

    MONTY

    MONTY

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    TEXAS A & M DID A STUDY & FOUND THE WHIRLYBIRD VENTS RELEASE ZERO HEAT WHILE MOVING. THERE IS NO WAY FOR THIS DESIGN TO "DRAW" HEAT OUT WHEN TURNING.
    ANOTHER OPTION OR TWO IS RADIANT BARRIER PLACED OVER CEILING JOISTS. SEE

    What Is Radiant Barrier Reflective Insulation?
    Radiant barrier insulation is a reflective insulation system that offers a permanent way to reduce energy costs. Radiant barrier insulation systems reflect radiant heat energy instead of trying to absorb it. A pure aluminum radiant barrier reflective insulation is unaffected by humidity and will continue to perform at a consistent level no matter how humid it may be. A radiant barrier insulation system is a layer of foil facing an airspace and is installed in the envelope of a building.

    Most people are familiar with traditional insulating materials such as fiberglass, cellulose, Styrofoam, and rock wool. These products use their ability to absorb or resist (slow down) convective and conductive heat transfer to insulate (R-value). A third, seldom discussed but dominant form of heat transfer exists: radiant heat transfer. What are the differences among the three forms of heat transfer?





    Conductive: Direct contact. If you touch a pot on the stove, this is conductive heat transfer.

    Convective: Steam, moisture. If you put your hand above a boiling pot, you will feel heat in the form of steam. This is convective heat transfer.

    Radiant: Electromagnetic. Step outside on a sunny day and feel the sun’s rays on your face. You are feeling radiant heat transfer. All objects above absolute zero (-459.7 degrees F.) emit infrared rays in a straight line in all directions.

    A radiant barrier reflects radiant heat energy instead of trying to absorb it. What does this mean in your home or business? During the winter, 50-75% of heat loss through the ceiling/roofing system and 65-80% of heat loss through walls is radiant. In the summer, up to 93% of heat gain is radiant. If you are depending on R-value (resistance) alone to insulate against heat gain and loss, remember that thin layers of fiberglass are virtually transparent to radiant energy and are affected by changes in humidity (moisture levels). A 1-1/2% change in the moisture content of fiberglass insulation will result in a 36% decrease in performance (referenced from HVAC Manual 10.6; McGraw-Hill). A pure aluminum radiant barrier is unaffected by humidity and will continue to perform at a consistent level no matter how humid it may be.


    --------------------------------------------------------------------------------
    Testing and Approvals
    Building Officials and Code Administrators
    International Conference of Building Officials
    Southern Building Code Congress International
    Metropolitan Dade County (FL) Building Code Compliance Dept.
    United States Testing Company
    Tennessee Valley Authority
    Tennessee Technological University
    State of California
    Oak Ridge National Laboratory
    Texas A & M University
    ALSO SEE:

    NASA Quest > Aerospace Team Online 80% ||||||||||||||||||||
    ... thermal protection materials. An example of a thermal protection material
    is the ceramic tile on the Shuttle Orbiter. It uses heat ... 2002-11-01
    + Highlighted
    http://quest.arc.nasa.gov/people/journals/aero/raiche/arcjets.html - 16k

    /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    RADIANT BARRIER
    Technology Transfer Program - At Home with NASA 60% ||||||||||||||||||||
    ... Their NASA-derived Smart-House Radiant Barrier is designed to reflect away 95 percent
    of the sun's radiant energy. Pretty cool! Back to "At Home With NASA". 2005-10-12
    + Highlighted
    http://techtran.msfc.nasa.gov/at_home/home5.htm - 4k


    AT Technology Transfer Homepage 50% ||||||||||||||||||||
    ... As her alarm sounds, Amanda awakes refreshed and ready to face her busy day after
    sleeping snugly in a home insulated with radiant barrier technology developed ... + Highlighted
    http://technology.jsc.nasa.gov/space_foundation.cfm - 28k


    Innovation (Jan/Feb 97) - Insulation 40% ||||||||||||||||||||
    ... Energy Q Radiant Barrier is the commercial name for the material, manufactured
    and marketed by Tech 2000 LLC of Roswell, Georgia. ... 1997-02-01
    + Highlighted
    http://nctn.hq.nasa.gov/innovation/Innovation51/insulatn.htm - 4k

    /////////////////////////////////////////
    OPTION # 2 IS A CERAMIC COATING OVER SHINGLES IN ANY COLOR MATCH.
    THIS
    SEE:
    http://www.mascoat.com/
    INFRARED SURVEY;
    sale-192056753@craigslist.org

    THERE'S YOU SOME OPTIONS,
    MONTY / FlatRoofExpert@aol.com
     

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