Home Energy Rating Systems: Sample Approval Methodology for Three Tools

摘要

Our experiment suggests that it is possible to assess the technical accuracy of different rating systems using a large simulation program as a standard yardstick, provided that the assumptions, as well as the modeling techniques used in developing the secondary standard, are fully documented. This is particularly important when working with rating system tools such as CALPAS3 that have very flexible inputs. For these simulation programs, the documentation must include not only the conditions being modeled, but if necessary, also the algorithms used. Based on our experience, for most calculational systems the certification procedure will require direct and close interaction between the certifying body and the rating system authors. If this certification procedure is to be workable, there needs to be sufficient general agreement on building operations assumptions, selection of a standard program, and the modeling techniques for generating the secondary standard. Thus, some national consortium of agencies and trade associations must define standard building operating conditions such as indoor thermostat setting and setback amount and duration, internal loads, window venting and shading schedules. It might also address the question of default values for furnace efficiencies and the COP for heat pumps and air conditioners at full and part load. The choice of the standard simulation program and the modeling methodology should be carefully scrutinized, and will no doubt generate some controversy. However, we feel that this approach will at least provide a benchmark for comparing various rating systems and is preferable to the current incompatibility of different systems or ad-hoc comparisons that are difficult for others to evaluate. 6 refs., 4 tabs. (ERA citation 10:039404)