Re: [TRNSYS-users] mean radiant and operative temperature

Dear Karol,

just a brief answer:

1.) The parameters of Type are defined in the Trnsys Studio at the Tab parameter

2.) The two NTYPEs are the same if
- the thermal zone has one airnode only and
- longwave radiation mode = STANDARD

NTYPE 24: For being backwards compatible it is always calculated by

DO NS=N1,N2 ! all surfaces of airnode

OUT(IOUT)=OUT(IOUT)+AREA(NS)*TSI(NS)

TOTAREA=TOTAREA+AREA(NS)

ENDDO

OUT(IOUT)=OUT(IOUT)/TOTAREA

NTYPE 120:

a) Longwave radiation mode = STANDARD:
DO NS=N1,N2 !all surface of zone to which airnode belongs

TMSURF=TMSURF+AREA(NS)*TSI(NS)

TOTAREA=TOTAREA+AREA(NS)

ENDDO

OUT(IOUT)=TMSURF/TOTAREA !area weighted mean surface temperature

b) Longwave radiation mode = DETAILED:
caluclation based Gebhart factors. The Gebhart method involves the view factor from the comfort point to the surfaces

and the therewith the position in the room with respect to the surrounding surfaces.

Best,

Marion

Von: Karol Bandurski [mailto:karol.bandurski@put.poznan.pl]
Gesendet: Freitag, 30. März 2012 17:20
An: trnsys-users@cae.wisc.edu
Betreff: [TRNSYS-users] mean radiant and operative temperature

Dear All,

I have 2 question:

1) In manual vol. 5 (introduction) I have read:

The third parameter gives the WEIGHTING FACTOR between air and mean surface temperature for the calculation of an operative room temperature. The inputs and outputs of TYPE 56 depend upon the building description and options within the TRNBUILD program. TRNBUILD generates an information file describing the outputs and required inputs of TYPE 56.

Where can I found/ set this factor?

2) What is the exactly difference between:

NTYPE 24

TMSURF

weighted mean surface temperature of airnode

[°C]

and

NTYPE 120

TMRLW

Mean radiant temperature (longwave only)

[!C]

The first is calculate according to surface area, and second is calculate according to surface area and distance from person?

Kind regards,

------------------------------------------------

Karol Bandurski MSc.

Institute of Environmental Engineering

Poznan University of Technology