The Value of the EWIT Computer Program in Identifying Economically Viable Retrofit Options for Existing Commercial Buildings

Abstract

The Energy What If Tool (EWIT) program developed by the New Mexico firm of Area. Inc., offers architects and environmental designers a new and viable means to model the energy performance of their building designs while in the schematic phase by means of a personal computer. Previously the only way that such data could be obtained was by purchasing time on mainframe systems to run such programs as BLAST or DOE II. EWIT, however, is a program designed specifically to be run on the IBM personal computer; a machine well within the means financially of even the most modest office. The program yields data proven accurate to within 80-90% of the aforementioned BLAST and DOE II mainframe programs. The purpose of this research effort is to investigate EWIT's potential as a tool for evaluating retrofit options for existing commercial buildings. To achieve this goal two case buildings in the Denver area were analyzed by means of the EWIT program. The first building is a one story structure of 10,000 square feet in floor area while the second is a hi-rise office building of almost a million square feet. The goal of the project is to produce a documented procedure for utilizing EWIT in retrofit applications and in the process develop VISICALC financial templates that can be integrated with the output from EWIT which would provide a comparative economic basis where the merits or shortcomings of various retrofit options can be quickly determined. While the above two case studies were conducted, space limitations would allow only the findings for the smaller structure (day care center) to be published in these proceedings. However, this case study does present a comprehensive picture of the EWIT retrofit analysis and its potential to architects and designers.