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Re: [EnergyPlus_Support] Advanced surface concepts
1. When OtherSideCoefficients are used, the surface temperature from the
OtherSideCoefficients becomes the "frontier". Exterior walls and walls between
thermal zones do not require the use of OtherSideCoefficients.
2. PMV is very sensitive to clothing, activity level, air velocity, and
humidity, as well as the air temperature and mean radiant temperature. Review
of these values should reveal why the PMV values are low.
Mike
On 13 Mar 2006 at 23:36, Fábyo Luiz Pereira wrote:
> Hello all!
>
> I'm trying to simulate a hospital floor and to consider the interaction
> between
> rooms common walls I have considered the "OtherSideCoefficients". Knowing
> that
> "OtherSideCoefficients" controls only the temperature of the outer plane of
> a
> surface, first question is: this parameter controls only planes that makes
> frontier with the outdoor or it controls also planes that makes frontier
> with
> other thermal zone?
>
> I don't know how to determine the coefficients values that modifies some
> temperatures (user selected, outdoor dry bulb, ground and zone air) and the
> wind speed, but I also don't feel confortable to work only with a user
> selected
> constant temperature, because if I select a hot temperature, it will works
> good
> on summer, but on winter I will have really bad results for interior walls
> temperatures. So, my second question is: which values can I use for the
> coefficients?
>
> I try some values but my results for PMV are very strange. For example, in a
> single room, at 8 and 9 o'clock, I found these values:
>
> 8hs 9hs
>
> - Outdoor dry bulb----------- 26,70 C 27,80 C
> - Mean radiant temperature--- 23,38 C 23,55 C
> - Zone mean air temperature-- 24,91 C 25,15 C
> - Fanger PMV----------------- -1,90 -0,08
>
> For me, the difference between PMV are very high and don't happen on
> practice.
> Searching for an explanation, I found that people activity during sleeping
> hours (23 - 8 hs) is low: 72 W/person against 100 W/person in the rest of
> the
> day. Lamps and electric equipments are turned on at 8hs and are designed for
> 180 W. In my view point, the low night clothing insulation (0,6 clo) is more
> influent in these results.
>
> I have observed that PMV is very sensitive by changing the coefficients,
> because I have found values for PMV near -8 in summer design day for Brasil,
> that is really impossible.
>
> Thanks.
>
> _______________________________
> M.Sc. Engº Fábyo Luiz Pereira
> Fone: +55 51 8118-5052
> http://www.fluizp.1br.net
>
>
>
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========================================================
Michael J. Witte, GARD Analytics, Inc.
EnergyPlus Testing and Support
EnergyPlus-Support@xxxxxxxx
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