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PMV-PPD Mistake in Energyplus

asked 2020-10-21 14:41:29 -0600

atmaca gravatar image

updated 2020-10-24 11:06:30 -0600

When I read the Pmv-Ppd values in the Energyplus program, I get values that do not fit the Fanger equation. For example, PMV is -0.3, PPD is 33% or PMV is -0.5, PPD is 38%. Do you think these results are correct?

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through the calculate,I think it's wrong.the formula is PDD=100-95exp(-0.03353PMV^4-0.2179*PMV^2).but my PSS value isn't from the energyplus I did the calculations myself

YAQ gravatar imageYAQ ( 2020-10-23 08:51:40 -0600 )edit

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answered 2020-11-12 00:52:04 -0600

Jmythms gravatar image

Hi!

Could you provide more details about the problem?

I just checked with a simulation using the "RefBldgSmallOfficeNew2004_Chicago.idf" in the example files and "USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw" weather file that comes with the EnergyPlus v9.4 installation.

I think the EnergyPlus calculated value for PPD agrees with the Fanger equation (same equation in the EnergyPlus code here) with the maximum percentage error being 21%. For a PMV value of -0.30006, the PPD by EnergyPlus was 6.87, and the error in PPD calculation was 2.15E-06% which is very small.

Maybe we could help you if we got more details.

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answered 2020-11-18 03:48:06 -0600

EnergyPlus PMV and PPD are right.

Just for information, they are referred to the previous calculation time step than reported. Therefore when reading simulaiton outputs, PMV/PPD values are calculated with reference to previous timestep MTA, MTR, VEL, RH, CLO and MET values

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Asked: 2020-10-21 14:41:29 -0600

Seen: 72 times

Last updated: Nov 18