[TRNSYS-users] Uvalue

Fri Apr 22 00:40:00 PDT 2016

Hi Jakob,

yes sir you are right. i get desired results by using Ntype 19  as you told
me and for long wave radiation exchange input Tsky and calculate Qsky with
Ntype 83 which gives me good  and desired results and get trend of u value
with respect to the change in temperature. Thanks a lot sir.

Best regards
Adnan

On Fri, Apr 22, 2016 at 4:31 PM, hotline <hotline at transsolar.com> wrote:

> Dear Adnan,
>
>
>
> the input Tsky is used for longwave radiational exchange. Your approach
> seems fine to me.
>
>
>
> 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 rasheed
> *Gesendet:* Donnerstag, 21. April 2016 16:18
> *An:* TRNSYS users mailing list at OneBuilding.org
> *Betreff:* Re: [TRNSYS-users] Uvalue
>
>
>
> 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
>
>
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>
>
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