AccuRate: 2nd generation nationwide house energy rating software

This note, previously described the NatHERS software and was originally published in November 1998 by John Ballinger. The software has now been extensively upgraded and renamed AccuRate.

The CSIRO has been developing energy building thermal performance simulation tools for well over 30 years. The new AccuRate software represents the latest step in the evolution of the ZSTEP simulation software (first operated in 1974) which derived from a variety of earlier software and research dating back to the early 1960s. While a full year’s simulation took around 16 seconds on a mainframe computer, the total job turn around took several hours for processing cards, printouts etc. With the rapid development of computer technology and the advent of the personal computer the ZSTEP simulation software was given a text based data entry system and was released as CHEETAH making data input far easier. It also added a variety of graphical outputs of temperature and loads, together with further development of several key algorithms and the development of a multi-zone model. In the 1990s the development of graphical user interfaces for personal computers allowed the development of easier to use data entry software leading to the development of NatHERS.

AccuRate updates the data entry system to the latest graphical user interface standards and makes a number of significant improvements to the calculation engine. These improvements reflect both the unique needs of the Australian climate by allowing for the physiological cooling effect of air movement, and some of the latest developments in international simulation techniques are incorporated, such as the ability to integrate the latest developments in glazing technology.

note summary
  1. Brief history
  2. Validation of CSIRO thermal simulation engine
  3. New features of the software
  4. Understanding energy ratings
  5. Use of the software in regulation