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Re: [EnergyPlus_Support] Why does E+ lose accuracy for lower values of the space discretization constant?




Hi Saleh. I am glad you answered.
Yes, I am sure the number of nodes increase by decreasing the Space Discretization Constant (C). I quote from the Engineering Reference Documentation: "Lower values for the Space Discretization Constant yield more nodes, with higher values yield fewer nodes".
I already modified the Convergence Criteria, using the lowest value. My results got better, but still, the same tendecy came out: lower values for C would generate lower accuracy. Why could this be happening?
When I read the Engineering Reference Documentation I found kind of a definition for the Convergence Criteria. I quote: 
Because the solution is implicit... The Gauss-Seidell iteration loop is the inner-most solver and is called for each surface. It is limited to 30 iterations but will exit early when the sum of all the node temperatures changes between the last call and the current call, normalized by the sum of the temperature values, is below 0.000001C. This convergence criteria is typically met after 3 iterations...