A new release of CSIRO's AccuRate software package is now available from Hearne Scientific Software.
AccuRate is the fully featured software package developed by CSIRO for rating the energy efficiency of residential building designs.
The AccuRate software package is a greatly improved version of NatHERS, which has been used to rate residential buildings for more than 10 years.
The limitations of NatHERS have been addressed in AccuRate.
The key improvements are improved natural ventilation modelling, a library of standard building materials as well as the ability to enter new ones, improved modelling of roof spaces, sub-floor spaces, skylights and the availability of up to 50 thermal zones within one house model.
CSIRO's AccuRate software package is the Australian national standard for residential building energy simulators.
The New Zealand edition of AccuRate is expected to be available in January 2008.
AccuRate New Zealand is currently being developed by CSIRO, it will be distributed by Hearne Scientific Software in Auckland and supported by Energy Rating Software Support.
What is new in AccuRate:
Some additional concrete masonry block walls with various arrangements of core fill have been added as follows:
- 190 and 140, denseweight and lightweight, core-filled at 1800, 1400, 1000 and 600 centres
The thermal properties for existing concrete blocks have been revised slightly
Some new types of concrete blocks have been added:
- 190 denseweight (fully core-filled)
- 190 lightweight (fully core-filled)
- 140 denseweight (fully core-filled)
- 140 lightweight (fully core-filled)
- 110 denseweight (solid)
- 110 lightweight (solid)
- 90 denseweight (solid) - replaces 90 denseweight (core-filled
- 90 lightweight (solid)
The thermal properties for existing Timbercrete blocks have been revised
The Timbercrete (solid) and Timbercrete (hollow) blocks have been replaced by:
- Timbercrete (solid low-density: 900 kg/m³) - replaces Timbercrete (solid)
- Timbercrete (solid mid-density: 1000 kg/m³)
- Timbercrete (solid high-density: 1100 kg/m³)
- Timbercrete (hollow low-density: 900 kg/m³) - replaces Timbercrete (hollow)
- Timbercrete (hollow mid-density: 1000 kg/m³)
- Timbercrete (hollow high-density: 1100 kg/m³)
The building data report now allows up to three lines for the construction description. In rating mode, windows must have Holland blinds as the indoor covering. An error is generated if they do not. In Non-rating mode, windows may have any indoor covering
In the construction libraries supplied, the surface colours and (for roofs) outdoor surface emissivities now default to not specified
New window files for EcoClassic windows added to the all_windows library
New roof window files for some Velux products are included
What has been fixed in AccuRate:
- Emissivities of roofs above a zone of type roofspace were always set to the default value of 0.9 instead of the user-specified value. This has been fixed. The bug would have affected very few projects. Note that this bug did not affect roofs above other types of zones
- A bug in the calculation of pressure coefficients that affected non-rectilinear floor plans has been fixed
- The glazing system U and SHGC values at NFRC displayed in the Constructions page have been corrected to agree with the values available from manufacturers. The calculations are not affected
- When AccuRate was in demonstration mode, selecting new project set the postcode to 0, which could not be changed, resulting in an error message. This bug has been fixed
- Some single-glazed A&L sliding doors were erroneously described as double glazed. This has been fixed
- A bug in the original NatHERS treatment of low-e single glazing with an indoor covering has been fixed. The bug negated the effect of the low-e glazing when an indoor covering was used
- AccuRate now adjusts the conditioned floor area for houses with floor/ceiling voids, so that it is no longer necessary for users to create a two-storey zone when there are large voids
- In rating mode, an error message is issued if the engine stops during the calculation
- An error in the window data for Generics (applied film on 3mm clear) has been fixed. This error generated a zero-thickness air gap which prevented the simulation from running
- Selecting Windows|Databook or Windows|Errors before opening a project no longer generates an error and bug report
- Results that were just under a half-star value were sometimes incorrectly reported as N.5 Stars, although only N solid star images were (correctly) displayed. This has been fixed
What has changed in AccuRate:
- Some problems with numerical stability in the ventilation calculations have been found when openings in internal walls are classified as permanent. The effect of the problems is variable, depending on climate and the number of permanent openings. Until this problem can be fixed all openings in internal walls will be set to controlled irrespective of the setting in the user interface. This change does not compromise the benefits of natural ventilation.
- In consultation with the NSW government, postcodes for the Tamworth region (2339-2347) and the Gunnedah region (2380-2382) have been changed from Climate zone 14 (Armidale) to cimate zone 48 (Dubbo). A further review of NSW postcodes is under way
- Generic window descriptors have been improved. Projects created with V220.127.116.11 will still run without modification. However for clarity you may wish to replace generic windows that use the old descriptors with the new ones
- Air gap thicknesses are now described in terms of thickness ranges (e.g. 40mm is replaced by 31-65mm). For air gaps below 13mm, see help, supporting data, material properties, overview which gives a method for estimating their thermal resistance
- The cellular insulation material can now be found under insulation (bulk) - specified resistance
All the updates for AcccuRate v18.104.22.168 can be downloaded free of charge by licensed users with current maintenance from energy rating software support.