The u-value shown in TRNBuild is based on the wall materials but also includes an assumed combined heat transfer coefficient to the inside and outside surfaces (7.7W/m2.K inside and 25 W/m2.K outside). The value is only for display purposes because Type56 calculates the inner and outer convection and radiation heat transfer coefficients internally as a function of time as the simulation progresses. There is an NTYPE among the outputs if you want to know what the actual (time dependent) u-value of the wall is. Kind regards, David
At 09:30 3/15/2007, Issa Jaffal wrote: >Dear All >When i was trying to make a new wall type in the wall type manager; i >couldnt explain how the Uvalue in the wall type manager is calculated, >for istance: > >if i make a wall with a single layer of 0.1 m of Concrete U-value = >4.595 and if i make a wall with a single layer of 0.2 m of Concrete >(same layer type) U-value=3.770 but normaly the U-value will be devided >by 2 if i double the thikness form 0.1 to 0.2!!! > >I tried to change the values of convective heat transfert coefficient >but the Uvalue didnt change: > >So how we can explain theses values the U-value ? > >Regards >Issa JAFFAL >_______________________________________________ >TRNSYS-users mailing list >[email protected] >https://www.cae.wisc.edu/mailman/listinfo/trnsys-users **************************************************************************************** Thermal Energy System Specialists (TESS), LLC David BRADLEY 2916 Marketplace Drive - Suite 104 Partner Madison, WI 53719 Phone: (608) 274-2577 USA Fax: (608) 278-1475 E-mail: [EMAIL PROTECTED] Web Pages: http://www.tess-inc.com and http://www.trnsys.com "Providing software solutions for today's energy engineering projects" **************************************************************************************** _______________________________________________ TRNSYS-users mailing list [email protected] https://www.cae.wisc.edu/mailman/listinfo/trnsys-users
