[Bldg-sim] simulation software

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I agree with Jeff.
Different programs may produce different energy savings results for USGBC LEED certification, depending on (a) the competence level of the program user, (b) the technical in-depth knowledge they have of this subject, (c) their experience in developing real buildings, (d) the design criteria that they use and (e) how well they understand the program they are using.
Theoretically all programs should produce the same results for a given project if the inputs are identical and the programs use the same methods-equations for analyzing envelopes, systems and plants. EnergyPlus uses the Heat-Balance method for Loads whereas all the other programs use the Transfer-Function method. Systems & Plants depend on the performance curves of the equipment.
Decisions have to take into account first & maintenance costs, availability of equipment parts and maintenance staff, reliability and durability of systems, positive environmental and acoustic impacts, and client preferences. This requires experience working on real buildings. A mechanical engineering degree and P.E. are more suitable qualifications for energy analysts than LEED A.P.
The ?percent energy savings? requirement of LEED can be misleading since it is affected by different design criteria, process loads, internal loads schedules (these items have to be the same in the baseline and proposed models) and the program used. The higher the common items in the baseline and proposed, the lower the ?percent? energy saved. Sixty percent energy savings does not necessarily mean an optimally designed, long lasting, stable and cost-effective building at the given (particularly urban) location.

Varkie Thomas's picture
Joined: 2011-09-30
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