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Dear Antoine, looking at the calculation, it the resistance
is always active when the shading is active. Maybe you confused due to the influence of
the frame? The u-value of the frame is not influenced by
the additional resistance of the shading. The NTYPE 50 UWIN is calculated of three
different parts: a) Centre of
glass b) Edge of glass (influenced by the
spacer) c) Frame The Uglas (centre of glass and edge of
glass) without the inner and out outer heat transfer is calculated by Redge=(1/alfain+(rshdin*shdin)+1/uedge .
+(rshdout*shdout)+1/alfout)/fe Rcenter=(1/alfain+(rshdin*shdin)+1/ucentr .
+(rshdout*shdout)+1/alfout)/fg Rges=Redge*Rcenter/(Redge+Rcenter) UGLAS=1/(Rges-1/alfain-1/alfout) Then the frame is included: UGL(N)=UGLAS* (1.-FFRAM)+UFRAM*FFRAM ! total window u-value without inner and
outer heat transfer Finally the NTYPE 50 is calculated by: CASE (50) ! u-value of window (glass+frame)with
standard inner and outer heat trasnfer coefficients IF (HO.GT.30.) RO=0.04 IF (HO.LT.0.005) RO=0.0 IF ((HO.LE.30.). UGLK=1./(1./(UGL(NWI)/3.6)+0.13+RO) ENDIF OUT(IOUT)=UGLK*3.6 Best, Dipl.-Ing. Marion
Hiller Geschäftsführer: Dipl.Ing.
Matthias Schuler, Dipl.Ing. Von: Antoine Gautier [mailto:antoine.gautier@solamen.fr]
Dear
all I use the surface output Uwin to assess the thermal impact of an
external shading device. As you know the thermal properties entered for the shading devices are
effective only if a shading device is actually defined for the window in the
zone description. I get the following results whereas I specified DeltaR = 0.06 m2.K.h/kJ
in input. Does anybody understand this better than I do? i.e. why does the
shading factor modify the thermal impact though the shading device is only
active during periods of time with zero irradiation? Why do I not get the
expected DeltaR in output but half the value? Shading factor - Uwin w/o shading - Uwin with shading [kJ/h.m2.K]
- DeltaR [m2.K.h/kJ] 1 - 4.93 - 4.22 -
0.034 0.75 - 4.93 - 4.36 - 0.027 Thanks for your help -- Antoine Gautier antoine.gautier@solamen.fr |