The star rating that is calculated with BERS can be used to show compliance with the thermal regulatory requirements of the Building Code of Australia (BCA). It is accredited under the Federal Government Nationwide House Energy Rating Scheme.
The graphics based data entry interface has been designed to make the process of thermally modelling buildings fast and accurate.
All building elements are accurately dimensioned when drawn by the user with a mouse.
Information about the building and its environment is selected from graphics screens.
Properties and dimensions can be easily checked or changed with a mouse click on the plan.
The position of building elements can be easily changed.
Help screens are available to guide the inexperienced user.
Calculated data is displayed in graphic form as well as being saved as files or documents.
Plan drawings can be imported and displayed in the background.
- Plans can be mirror imaged at the click of a button.
Multi-storey buildings comprised of many zones can be modelled.
Rooflines are drawn by the user. Eaves widths for walls, doors and windows are calculated automatically.
Shading of windows and walls by adjacent walls is automatically calculated.
Overshadowing by neighbouring buildings, vegetation, mountains etc requires the dimensions and location of the obstacle to be entered only once relative to the building.
The dimensions of walls, doors and windows are displayed as elevations that are scaled to the plan dimensions.
Properties can be copied and then pasted to other elements of the same type.
User constructed information such as window shading schedules, user and client profiles, default building properties etc can be saved, and then later opened and used for future projects.
Ventilation is automatically calculated from the dimensions and location on the plan of windows, doors and other openings in combination with the wind data in the climate file.
Information is displayed to different levels of detail.
Features include being able to search the database of commercially available windows to find windows with similar properties.
Analysis of Data
The thermal performance of a building can be analysed in terms of heating and cooling energy per floor area. This is converted to a STAR rating for regulatory compliance.
A star rating is also assigned to each zone in the building to allow the user to easily identify which zones are working well and which ones need changes to improve performance.
A record of the last 10 simulations is saved and can be easily accessed to assess progress in increasing the performance of a building.
The thermal performance of "free running" buildings can also be assessed.
Hourly temperatures of any zone for up to 4 projects can be displayed graphically.
The starting date and duration of a period of interest can be selected for display.
Hourly temperatures can be automatically selected for the display of extreme periods such as "a hot week in summer", "a cold week in winter" etc.
Any of the 69 climate files can be displayed as hourly temperature graphs as described above.
Building element properties such as the R-Values, U-Values, Solar Heat Gain Factors, graphs of window transmittance and absorptance curves etc are displayed as building elements are selected.
The mathematical “engine” at the heart of the BERS program is the same 2nd Generation CSIRO thermal simulation engine used by ACCURATE. ACCURATE does not have a graphics user interface.
BERS Pro Plus is the new version of BERS Pro that includes all the data entry required to calculate the total energy consumption of the house including heating, cooling, hot water, appliances, cooking, cleaning etc. Outputs include a breakup by energy source as well as the carbon footprint of the household.
The BCA simply requires the calculated theoretical energy needed to be added to the building (heating) plus the energy needed to be taken out of the building (cooling) per square metre of conditioned floor area, to be converted to a star rating. This figure has an arbitrary "area adjustment factor" applied to it to bias the rating more towards smaller houses. This combined energy per square metre does not take into account the efficiency of the energy delivery system nor the size of the house. The problem with this approach is that it's possible to have a large house with a high (good) star rating requiring much more heating and cooling energy than a small house with a much poorer star rating. It also provides exactly the same rating for two identical houses in the same climate even though one may have a much more efficient heating and cooling delivery system than the other. Similarly the same rating would apply even if one of the houses uses fuel sources with much lower carbon emissions than the other.
In addition to calculating the current star rating required under the BCA, BERS Pro Plus uses the area of the house and the efficiency of the delivery system to calculate the electric, gas and/or wood energy that is used by the house to maintain comfort. It also allows all the other appliances in the house to be modelled so that the total fuel energy can be calculated. It then converts this total energy into the annual carbon-dioxide released into the atmosphere by the household. This is a more comprehensive metric to use than current BCA star rating when comparing the energy efficiency of two houses.
BERS Pro Plus supersedes BERS Pro and includes all the previous capabilities and analysis that provide building envelope star ratings. Three versions of the CHENATH calculation engine are included.
The first, CHENATH213 is the old engine containing the ventilation bug that the NatHERS administrator still uses for accreditation. The second, CHENATH220 has had the ventilation bug fixed 3 years ago. There is very little difference in the results from this engine but it won't hang like the faulty version. The third, CHENATH223 is the engine developed by CSIRO for Solar Logic that replaces the standard internal heating load used for regulatory purposes with the heating load due to the actual appliances that the user models. Only the first and second engine will output a star rating. The third engine is provided to allow assessors to do energy audits, but cannot and must not be used to provide the star rating required by the BCA.
BERS Pro requires at least 512 MB of RAM and 700 MB of virtual RAM. The calculations can take a while so the faster the processing the better. The graphics card should have onboard memory and fast display otherwise plan manipulation may be jerky.
The current version has been compiled for Vista, XP and Win2000 but also works under Win7.
There have been instances reported where nVidia GeForce graphics cards in laptops have failed to display BERS Pro correctly so if you are purchasing a new laptop it would be prudent to load and test the BERS software before buying the laptop. If you don't have a copy of BERS to test download (the now outdated) demonstration version. Remember you must install and run the software in administrator mode under Vista and Win7.
Upgrades and add-ons will be available for downloading from the Solar Logic website or may be available at no charge during training sessions.
Data for new building materials will be continually available for downloading, as will be any other enhancements and additions.
Solar Logic will continue to support users via the BERS help desk. We recognize the need to respond promptly to questions from practitioners earning a living. Queries will be attended to within 24 hours if possible. The help desk will not be available on weekends and public holidays.
Help in using the software is only available to those who have successfully completed the BERS Pro training.
Updates for BERS Pro can be downloaded here.
BERS Pro meets the ABCB (Australian Building Code Board) Protocol for second generation thermal simulation software, "Protocol For House Energy Rating Software V 2006.1". This document can be downloaded from http://www.abcb.gov.au/documents/energy/energy_rating_software_protocol_2006-1.pdf
BERS Pro can be used throughout Australia to show compliance with the BCA.
BERS Pro 4.2 110811 has been fully accredited by the NatHERS administrator to be used to issue NatHERS certificates.
Roof windows with internal blinds cannot be modelled in BERS Pro.