Evaluation of microcomputer energy analysis programs. Final report

The evaluation was performed by comparing building simulations provided by micro programs to those provided by the Building Loads Analysis and System Thermodynamics (BLAST) program. The two micro programs chosen for evaluation (OPCOST and SASEAP) are representative of the type of bin method calculations used in simplified energy analysis procedures. The evaluation was based on four factors: (1) the ability of the programs to calculate overall annual building energy consumption, (2) their ability to study design options for developing energy-efficient new construction, (3) their ability to calculate energy savings from various building retrofit options, and (4) the amount of input information required which would be considered judgemental in nature as opposed to building description oriented. The results of the evaluation showed that the microcomputer energy analysis programs could reasonably predict the proper ranking of design alternatives or retrofit options. However, the programs could not accurately predict total annual energy consumption. Thus, the micro programs should not be used to determine compliance with energy budgets. Likewise, the micro programs could not predict the actual energy savings due to a design alternative or a retrofit option. The results did not clearly illustrate which design options were modeled accurately.