Differences
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apps:biomet_pet [2017/11/11 08:39] – enviadmin | apps:biomet_pet [2022/07/31 16:56] – [PET] enviadmin | ||
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- | Despite its popularity, PET lacks a proper and comprehensive documentation. Basically, one needs to read the 2 papers Gagge et al. (1971) and Höppe (1984) -in german- plus the computer source code provided by VDI 3787. \\ | + | Despite its popularity, PET long time lacked |
- | It has to be noted, that there are some unlogical assumptions and errors in the original set of equations. In the ENVI-met implementation, | + | |
- | -The description still needs to be compiled | + | **In 2018, this gap has been closed by the paper "//The P.E.T. comfort index: Questioning the model//" |
- | Main changes to original PET in short : | + | In this paper as well as in ENVI-met paper it was noted that there are some non-logical assumptions and errors in the original set of equations plus coding errors in the code published in VDI 3787. In addition, there have been better parametrisations for the Mean Radiant Temperature (TMRT) which is is not directly a part of PET but widely influences the results. |
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+ | In the ENVI-met implementation of BIO-met, many of these errors have been corrected. As a consequence, | ||
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+ | Main changes | ||
* For the indoor setting, the turbulent exchange coefficients for heat and vapour are calculated using the indoor air velocity instead of keeping them at the outdoor value | * For the indoor setting, the turbulent exchange coefficients for heat and vapour are calculated using the indoor air velocity instead of keeping them at the outdoor value | ||
* The sweat rate and the amount of sweat on the skin is set to zero when starting calculating the indoor environment | * The sweat rate and the amount of sweat on the skin is set to zero when starting calculating the indoor environment | ||
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+ | The suggestions form Walther and Goestchel (2018) | ||
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===== General Idea ===== | ===== General Idea ===== |