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  1. 07-26-2011, 06:39 PM #1
    tedkidd's Avatar
    tedkidd
    tedkidd is offline Professional Member*
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    Great building science blog - Energy Vanguard

    Here's an interesting article on radiant barriers. Haven't finished reading it, maybe my prejudices against measures outside of the thermal boundary will be proven false...
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.
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  2. 07-26-2011, 07:12 PM #2
    54regcab
    54regcab is offline Regular Guest
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    Great article. We did an informal attic temperature test in our attics a few weeks ago when temps were 105 outside. Wind was about 8mph.

    1: Ridge vent house was 155
    2: Power vent house 145
    3: Attic turbine house 145
    4: Radiant barrier stapled to underside of roof 125

    Based on the informal test in our neighborhood it seems the radiant barrier is what REALLY works !!
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  3. 07-26-2011, 07:21 PM #3
    dan sw fl
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    Hmm

    Quote Originally Posted by 54regcab View Post
    Great article. We did an informal attic temperature test in our attics a few weeks ago when temps were 105 outside. Wind was about 8mph.

    1: Ridge vent house was 155
    2: Power vent house 145
    3: Attic turbine house 145
    4: Radiant barrier stapled to underside of roof 125

    Based on the informal test in our neighborhood it seems the radiant barrier is what REALLY works !!
    Foam insulation roof joists ... 114.?
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art".

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities
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  4. 07-26-2011, 08:18 PM #4
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    Hunter844
    Hunter844 is offline Professional Member*
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    Reflective roofing material? Wouldn't that be best?
    "Gentlemen. You can't fight in here. This is the War Room!"-Dr. Strangelove (1964)
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  5. 07-26-2011, 08:29 PM #5
    tedkidd's Avatar
    tedkidd
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    Quote Originally Posted by dan sw fl View Post
    Foam insulation roof joists ... 114.?
    No Dan, the first summer after spraying my attic it was never more than 5f hotter than outside. That was before AC in the house.

    I recently redefined a small commercial attic, they went up there the other day and it was 1/2 way between indoor and outdoor temperature instead of the typical 25f hotter than outdoors.

    The 2 ton unit cooling the space was able to keep up for the first time. Never done that before with OD temps above 85f.

    Some of my spray foam jobs.
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.
    Reply With Quote Reply With Quote
  6. 07-27-2011, 09:12 AM #6
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    Hunter844
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    Off subject but one of his blogs he mentioned "Pressure Relief in Master bedroom" when mentioned proper HVAC design.

    What does he mean by that?
    "Gentlemen. You can't fight in here. This is the War Room!"-Dr. Strangelove (1964)
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  7. 07-27-2011, 09:46 AM #7
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    Shophound
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    Hmm...article says same thing about PAV I have...that using a PAV is addressing the symptom, not the source. That pumping out hot air with a PAV means that all of the construction materials had to get hot first in order to heat the air. And that they're still hot even with the PAV running.

    Go radiant barrier!

    I also agree with comments below in the article where if no ducts reside in the attic, and there's a reasonable pressure boundary at the ceiling/attic floor juncture, better insulation is more effective in this case than RB.
    "In this house we obey the laws of thermodynamics!"

    - Homer Simpson
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  8. 07-27-2011, 10:21 PM #8
    energy_rater_La
    energy_rater_La is offline Professional Member*
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    in addition to florida solar energy center having good rb info
    oakridge also has good articles.
    The cure of the part should not be attempted without the cure of the whole. ~Plato
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