Re: [EnergyPlus_Support] Re: WindowMaterial:Shade - different air-flow permeability same results.

Historically, AFN and windows glazing are not related...only if you make them. Window definitions were for radiation calcs and AFN for air flow. It may be that your "Airflow Permeability" needs to be linked in with an AFN object, or that it only pertains to radiation. You'll have to carefully check the docs.

On 4 Oct 2016 9:39 pm, "katdra83@xxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

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Hi Jean,

It is a setting of the WindowMaterial:Shade which is used (according to i/o ref) for drapery and translucent roller shades. I donâ??t have a certain shading system in mind (except that it is an external one). I just want to run a parametric study with different values in solar transmittance and airflow permeability to check their effect in interior temperatures. I began by comparingÂ shadings with same solar transmittance but different airflow permeability (their description follows) to get almost the same results in AFN Zone infiltration Air Change Rate (described in previous message). I expected higher AFN Zone infiltration Air Change Rate (ventilation and crack flows are summed in that rate, right?) for the case of â??Shade50pâ?? compared to â??Shade50pNopermâ?? where the shading blocks totally the airflow (Airflow Permeability = 0). Isnâ??t it a rational assumption that when there is an obstruction in front of the window the ventilation rate will be less compared to an ubstructedÂ window ? In both cases there is an AFN and the windows open according to the same schedule.
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WindowMaterial:Shade,

Â Â Â Shade50p,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Name

Â Â Â 0.5,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Solar Transmittance {dimensionless}

Â Â Â 0.4,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Solar Reflectance {dimensionless}

Â Â Â 0.45,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Visible Transmittance {dimensionless}

Â Â Â 0.35,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Visible Reflectance {dimensionless}

Â Â Â 0.45,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Infrared Hemispherical Emissivity {dimensionless}

Â Â Â 0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Infrared Transmittance {dimensionless}

Â Â Â 0.003,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Thickness {m}

Â Â Â 0.1,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Conductivity {W/m-K}

Â Â Â 0.05,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Shade to Glass Distance {m}

Â Â Â 0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Top Opening Multiplier

Â Â Â 0, Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Bottom Opening Multiplier

Â Â Â 0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Left-Side Opening Multiplier

Â Â Â 0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Right-Side Opening Multiplier

Â Â Â 0.5;Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Airflow Permeability {dimensionless}

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WindowMaterial:Shade,

Â Â Â Shade50pNoperm,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Name

Â Â Â 0.5,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Solar Transmittance {dimensionless}

Â Â Â 0.4,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Solar Reflectance {dimensionless}

Â Â Â 0.45,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Visible Transmittance {dimensionless}

Â Â Â 0.35,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Visible Reflectance {dimensionless}

Â Â Â 0.45,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Infrared Hemispherical Emissivity {dimensionless}

Â Â Â 0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Infrared Transmittance {dimensionless}

Â Â Â 0.003,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Thickness {m}

Â Â Â 0.1,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Conductivity {W/m-K}

Â Â Â 0.05,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Shade to Glass Distance {m}

Â Â Â 0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Top Opening Multiplier

Â Â Â 0, Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Bottom Opening Multiplier

Â Â Â 0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Left-Side Opening Multiplier

Â Â Â 0,Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Right-Side Opening Multiplier

Â Â Â 0.0;Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â !- Airflow Permeability {dimensionless}

Â