[TRNSYS-users] Uvalue

adnan rasheed adnan.upm.spain at gmail.com
Thu Apr 21 07:18:14 PDT 2016


hi,
Thanks jakob you suggest me NTYPE 19.. to ..22 .i tried sum of N-types 19
and 20. and get desired trend of the u value as i change the required
heating temperatures 2, 4, 6, 8, 10, 20, 30, 40, and 50.

 if i am not wrong these ntypes are radiative and convective heat losses???
through the window .

but the problem is that i want to simulate at sky temp 0 and then -20, as
my simulation is only for 4 hrs in night time from 1 am to 5 am. i want to
simulate night sky radiation effect on heating requirement by using 0 and
-20 fix sky temperature. i use 0 and -20 sky temp in equation and connect
it to type 56 as tsky am i right here???

Best regards
Adnan


On Wed, Apr 20, 2016 at 11:22 PM, hotline <hotline at transsolar.com> wrote:

> Dear Adnan,
>
>
>
> please make sure that all other heat transfer effects (solar radiation,
> internal gains, convection, infiltration) besides heat flow through walls
> are switched off!
>
> you can use NType 19…22 to determine the heat flows at the front and back
> side of the wall. And please keep in mind that TRNSYS will simulate
> capacitive effects, too.
>
>
>
>
> Best
> Jakob
>
>
>
>
>
>
> _________________________________________________________________________________________________
>
>
>
> *Jakob Merk*
>
> TRNSYS Software Team
>
>
> *Transsolar Energietechnik GmbH*
>
> Curiestraße 2
>
> 70563 Stuttgart
>
> Fax:        +49 711 67976-11
> Email:    hotline at transsolar.com
>
> Web:      www.trnsys.de
>
>
>
>
>
>
>
> *Von:* TRNSYS-users [mailto:trnsys-users-bounces at lists.onebuilding.org] *Im
> Auftrag von *Adnan Upm Spain
> *Gesendet:* Mittwoch, 20. April 2016 16:07
> *An:* TRNSYS users mailing list at OneBuilding.org
> *Betreff:* Re: [TRNSYS-users] Uvalue
>
>
>
> Thanks Merk for your reply...
>
> I am using Ntype2 sensible heating demand and one out put Ntype 906 which
> give energy balance in it system also gives same value for heating.
>
> Regards
> Adnan
>
> Sent from my Sony Xperia™ smartphone
>
>
>
> ---- hotline wrote ----
>
> Dear Adnan,
>
>
>
> your approach makes sense to me. TRNSYS does calculate heat transport for
> each time step and is not using a fixed U-Value.
>
> Which TRNSYS outputs did use for q= convective and radiative heat loss ?
>
> I guess that using a wrong output could have coused your problem…
>
>
>
> Sincerely yours
> Jakob Merk
>
>
> _________________________________________________________________________________________________
>
>
>
> *Jakob Merk*
>
> TRNSYS Software Team
>
>
> *Transsolar Energietechnik GmbH*
>
> Curiestraße 2
>
> 70563 Stuttgart
>
> Fax:        +49 711 67976-11
> Email:    hotline at transsolar.com
>
> Web:      www.trnsys.de
>
>
>
>
>
>
>
> *Von:* TRNSYS-users [mailto:trnsys-users-bounces at lists.onebuilding.org
> <trnsys-users-bounces at lists.onebuilding.org>] *Im Auftrag von *adnan
> rasheed
> *Gesendet:* Mittwoch, 20. April 2016 13:13
> *An:* trnsys-users at lists.onebuilding.org
> *Betreff:* [TRNSYS-users] Uvalue
>
>
>
> hi everyone,
>
>
>
> i have one question i am stuck with this problem.
>
>
>
> 1- i want heating a room having one window, by using type 56
>
>
>
> inside temp = 10, 20, 30,....
>
>
>
> dry bulk temp= ambient  temp = outside = 0
>
>
>
> sky temp = 0 and -20
>
>
>
> i wanna see the change in overall heat transfer coefficient = u-value of
> glazing (window) by changing inside temperature using this equation
>
>
>
> U = Q / A(T) where
>
> U = U-value
>
> q= convective and radiative heat loss
>
> A = Area of window
>
> T = ambient and inside temp difference.
>
>
>
> i get results but TRNSYS giving me almost the same value of U for all temp
> difference. trend is not same as experimental U-value trend according to
> change in inside temp.
>
>
>
> anyone please help me with this is it possible to calculate U-value of
> window like this. or trnsys use fix U-value for the calculation of heat
> load.
>
>
>
> thanks in advance. for killing your time.
>
>
>
> Regards
>
> Adnan
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at lists.onebuilding.org
> http://lists.onebuilding.org/listinfo.cgi/trnsys-users-onebuilding.org
>
>
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