Frequently asked questions and answers

This is a so-called "FAQ" (Frequently Asked Questions) for the BSim program package. The number of questions and answers increases along with the incoming questions.





Installation

Question:
I have a PC running  Windows 7 (or Windows 8 or  Windows Vista) and I have tried to install BSim, but the installation do not start.

Answer:
It is probably caused by another program that blocks the installation program. So, close all running programs before starting the installlation.

If this do not work, a running process may be blocking the installation, which can be:
  • Logitec drivers,
  • Adobe processes,
  • Drivers for touch screens,
  • Some anti virus programs.
Open the Task manager - right click on the Windows task bar (normally found at the bottom of the screen) and select "Start task manager". Jump to the tab "Processes" and close running processes one at the time. Do not close processes marked with SYSTEM as username. 

If this do not work, you probably need to perform a "clean boot" of you PC (see a description of the procedure at Microsoft's support site: http://support.microsoft.com/kb/929135/en-us).

Question:
Can BSim run on a PC with a 64 bit operating system?

Answer:
SBi have made a test-installation of BSim on a 64 bit Windows 7 PC.

The installation ran without problems (given the rights appointed to the user accound used for the test installation).

Those functions that have been known to cause problems when upgrading the operating system (showing dialogs with graphics, simulation, showing results as graphics, and showing the User's Guide) were tested, and no errors or break-downs were encountered.

From this mini-test, there seems to be no ptoblems in installing en running BSIm on a PC equipped with a 64 bit Windows 7 operating system.

Question:
I get the following error message while installing BSim: "Unable to execute vcredist_x86.exe".

Answer:
Automatic update of the Windows operating system fails. Download and install "vcredist_x86.exe". Re-install BSim after having installed "vcredist_x86.exe".

In more recent versions of Windows, e.g. Windows 7, the functionallity of vcredist_x86 is already part of the system, and BSim will run without this additional installation.

Question:
What are the system requirements for a network server running BSim and how do I make the installation?

Answer:
Server requirements: There are no special requirements to a network server to be able to run BSim, though a minimum network speed of 10 Mbit is recommended for a quick start of the programs. Further it is necessary to have read access for the workstations in the folder where BSim is to be installed. 
If the building models are placed at the network, the speed of the network should be able to transfer large (typical + 8 Mb) result files and be able to handle long filenames. 
Server: Start the installation from the CD-ROM (or run setup02.exe downloaded from the Internet). On the 'Choose Destination Location' page select the 'Destination Folder' on the network where BSim is to be installed, and select 'Typical' or 'Custom' (to install the English help file) in the 'Setup Type' page.
Workstation: On each workstation install BSim choosing the 'Destination Folder' on the network, and select 'Compact' in the 'Setup Type' page. MDAC must be installed (if this update is required by the operating system) as well.
Updates: Later updates can be installed on the network, and no update is needed for the workstations.

Question:
It takes very long time to unpack an update of the program, what is wrong?

Answer:
If you have Outlook running it can cause a very slow execution of the installation. Try to shut down Outlook or other programs before installing BSim2002.

Question:
I get a program break down when trying to show graphics. What is wrong?

Answer:
You have probably not installed Microsoft Data Access Components (MDAC) on your PC. This can be done in different ways, depending on your operating system:
Windows 95:
1) Run DCOM95.exe from update page or the BSim CD-ROM to install DCOM.
2) Run MDAC_typ.exe from the update or the BSim CD-ROM page to install MDAC.
Windows 98 (version 1):
2) Run DCOM98.exe from the update page or the BSim CD-ROM to install DCOM.
3) Run MDAC_typ.exe from the update page or the BSim CD-ROM to install MDAC.
Windows 98 (version 2):
MDAC is part of the operating system.
Windows NT 4.0:
1) Run MDAC_typ.exe from the update page or the BSim CD-ROM to install MDAC.
Windows 2000:
MDAC is part of the operating system.
Windows XP:
MDAC is part of the operating system.

Question:
How do I determine which version of Windows 98 I have running?

Answer:
In Microsoft's knowledge base article Q234762 the following description is found:

"NOTE: To determine if Windows 98 Second Edition is installed on your computer, right-click My Computer, click Properties, and then view the contents of the General tab. If the words "Second Edition" are visible, Windows 98 Second Edition is already installed."

Question:
I get an error message when trying to install MDAC_typ.exe under Windows NT.

Answer:
In Windows NT you must have administrator rights to install MDAC. It should though always be possible to download the file for later installation with the rights as administrator.

Question:
I have just updated the complete program package. Why is there an inconsistency between the version number of the program and the help text?

Answer:
The help text is normally behind the development of the program. The latest version (see Miscellaneous) of the help text can be downloaded from the update page.


Configuration

Question:
Is it possible to change the number of operations to undo?

Answer:
Select "Options" from the SimView menu (right-click in one of graphic views) and change the number of "Undo Levels" to the number you like. The new number of undo levels will be invoked next time you open BSim2002 and will primarily affect major changes in the geometry.

SimDB Data base              

Question:
I can not create a new building element in the data base.

Answer:
You are probably using the standard data base (sbidata.mdb). This data base is write protected and new objects can not be added to the data base.

You have probably opened an "old" model, created with an earlier version of BSim. When you create a new model in the present version of BSim, a copy of the standard data base - or any other data base - is created with the same name as the project. This new database is not write protected.

You can work around this problem by creating a copy of the standard data base - or any other data base - in the explorer. If you make a copy of the standard data base (sbidata.mdb), you must change the properties so it is no longer write protected. This is done by right clicking (i.e. in the explorer) the new data base (*.mdb) and selecting the entry "Properties".

CAD import using SimDXF

Question:
Is it possible to import a model created in SimDXF to SimView in a way that typical profiles (Dwelling or Office) are present in the model - like when a new model is created directly in SimView?

Answer:
Yes, you can create a new model in SimView, select a database to copy and select the desired profile, but do NOT add a building. Select the entry Edit | Insert | Project and open the relevant DXF-project. Doing this imports the DXF-model into SimView with the selected profile.

Question:
How can I create a model with more than one story from a CAD-drawing imported in SimDXF?

Answer:
You must create a separate model for each story in SimDXF, i.e. Building0, Building1, etc. In SimView you then import the first story (Building0).

Then you import the next story (Building1) in SimView. This will occur as a new building. Then drag the second building (Building1) into the first building (Building0). This will add a second story to the first building.

The procedure is repeated for each new story in the final building model.

Air-movements

Question:
Is it possible to simulate natural ventilation among different thermal zones?

Answer:
No, but we are working on an extension to the existing natural ventilation module. Here is will be possible to simulate natural ventilation between zones and between the building and the outdoors. The module will be tested in practice before final release.

Surfaces

Question:
If a building is created having two rooms, i.e. one facing West and one facing East with a common face in-between, the program tells that face side 1 in the West room is facing the room. Switching to the East room face side 1 is also facing the West room.

I would anticipate that face side 1 should face the room you are located "in". Is the program capable of managing that side 2 is facing the room in one room and side 1 in the next room? As far as I can see it is not possible to change the order of the face sides in Finish Property except if the face is facing Outdoor.

Answer:
Normally, side 1 of a construction will face the room from where it was created.

In this context you should be aware of the Autoarrange facesides in the Options dialog of the SimView menu. This function ensures that the face sides are arranges automatically according to the following rules: - on floors, face side 1 will always be up - exterior constructions will always have side 2 facing Outdoor or Ground.

Question:
How is the net volume of a room calculated, or rather how are ceiling/floor located compared to the system lines?

Answer:
The net and gross volume is calculated from internal measurements. For faces facing the outdoors or ground, the system lines are located at the external face of the constructions, while they are located in the center line for internal constructions. Normally this gives no reason for confusion. However you must remember that if a model is changed in a way that a construction formerly facing the outdoors now faces an other room, the area and volume will change as the location of the constructions are changed compared to the system lines.

Example: When a 20 cm thick construction is changed from facing the outdoors to be facing an other zone, the wall will "move" 10 cm outwards from the original zone, and the net area will increase accordingly.

Question:
How do I ensure that the numbering of the face sides are correct? If a building with two rooms, one to the East and one to the West is created. In the shared face between the two rooms the program tells that face 1 of the shared face in room West faces room West and face 2 faces room East. But in room East the shared face do also have face 1 facing room West and face 2 facing room East.

Answer:
Normally face 1 faces the room from where the face is created (normally in the same order as the rooms are created). In Options from the SimView menu it is possible to select an option to ensure an automatic arrangement of faces in a defined way. With this option on the following rule will count: Floors will have face 1 upwards and external walls will have face 2 facing the OutDoor.

Question:
How do I simulate constructions with steel columns or steel profiles? Typically it is surface with both visible and not visible. Must I incorporate these in the model or are there other possibilities?

Answer:
There are thee options:

1) If the steel columns are located in the constructions, they can be treated as a thermal bridge, which can be modeled a separate construction with the right material layers. The area and the material properties of this construction must reflect the heat loss through the thermal bridge.

2) If the columns are located on the outdoor side of the constructions, they have NO influence on the thermal simulation of the building - except eventual shadows on the external windoors.

3) If the columns are located in the rooms, they do ONLY have influence if they significant add to the total thermal capacity of the room/building. In this case they can be modeled as an internal wall between two rooms in the same thermal zone or by increasing the thermal capacity of the innermost layer of the constructions. In the latter case the changed capacity of the innermost material layer must reflect the thermal capacity of the columns.

In other words: It is ALWAYS important to judge the building model and see if there are places where it is advantageous to simplify the model. In general you should ONLY model those part of the building, which is important for the problem you will investigate.

Rooms and thermal


Question:
How do I avoid modeling the entire building?

Answer:
You have the opportunity of defining virtual zones, say rooms or surface conditions with a well defined temperature. A virtual zone can be defined in three ways.

1) In the Finish property dialog you can define that both sides of the surface faces the same thermal zone. This ensures that the same temperature and moisture conditions exists on both sides of the surface at any time. The total thermal mass of the construction do take active part in the simulation.

2) In the Room property dialog you can define the temperature variation (over the year and the day) for any room, located OUTSIDE any thermal zone using the Room Temp button. This give the room the temperature and moisture variation defined in the Room Temp dialog at any time of the year.

3) You can add a virtual ground zone to the model, using the Ground button of the Site dialog. In this dialog you can define the temperature and moisture variation for the virtual ground over the year. In the Finish property dialog of all surfaces facing the virtual ground zone, you must define that face no. 2 of the surface faces this virtual zone.

Systems

Question:
BSim crash when I try to run a simulation with a model with hydronic floor heating/cooling. What is wrong?

Answer:
There are two possibilities for this problem:

The same control have been selected for floor heating systems in more than one thermal zone. If the same control strategy is to be used in more thermal zones, make a copy and use that in the second thermal zone after selecting the face to host the sloor heating system (use different face names for faces in different thermal zones).
Another reason may be that the thickness of the material layers above the floor heating pipes is less than the external diameter of the pipes.
Question:
BSim breaks down when I try to open the DayProfile tab from the systems dialog. What i s wrong?

Answer:
Some operating systems (Windows 95, Windows 98 version 2 og Windows NT) requires installation of MDAC (Microsoft Data Access) version 2,5 or more recent to be able to run BSim. From BSim version 3,2,8,2 the following dialog is shown when the program starts if MDAC is not installed or is too old.

mdac-error.jpg

If you click Yes, BSim will start, but not fully functional.
MDAC is found at the BSim CD-ROM under Updates for Windows or here.

Question:
How is the temperature rise over the engine in a ventilation system calculated in BSim2002? Wich value must I put for "pressure rise", if I have a central ventilation plant delivering 10.000 m3/h with a pressure rise if 1000 Pa and I want to simulate a single thermal zone using only 1000 m3/h. In the actual thermal zone I input 1000 m3/h, but should I put 100 Pa or 1000 Pa in the ventilation dialog for the actual thermal zone to obtain the correct temperature rise over the engine?

Answer:
DT = 1200/ DP * e.

where DT is the temperature rise, DP is the pressure rise and e is the total efficiency.

If your pressure rise is calculated from the real conditions, the temperature rise of the real air-flow will be increased by DT. You should thus not "modify" your DP.

Shadows

Question:
Is it possible to define a control of external shadows, i.e. as a deciduous three?

Answer:
No, this facility is not implemented, but it will be considered in a later update.

Handling


Question:
Do the calculated energy consumption for mechanical ventilation: FanPow, HtRec, ClCoil, HtCoil cover both the energy for heating and electricity? The energy consumption in tsbi5 are shown at the HeatBalance tab. If the values covers both electricity and heating consumption, the tab might rather be called EnergyBalance?

Answer:
In the energy balance both contributions for heating and "cooling" influencing the temperature and the humidity of thermal zone are shown. In this is counted all contributions of air at a given temperature and humidity, including the contribution from the mechanical ventilation system. The numbers calculated for the mechanical ventilation are all the energy flows, necessary to treat the air before blowing it into the thermal zone having the desired conditions.

The energy consumption to ventilation is a so-to-say "net demand/ consumption". The consumption of electricity in the fan engines is calculated from the air-flow multiplied with the increase in air-pressure divided with the total efficiency (in all units passed). The other consumptions are energy/heat transfers in the components of the system to the ventilation air (net). We do not include the consumption of electricity for pumps, running heat recovery units, etc.

Question:
How come there can occur a heat loss by transmission when the outdoor temperature is above the indoor temperature?

Answer:
The heat loss by transmission is determined by the difference between the indoor operative temperature and the temperature in the first material layer of the constructions. In periods there can thus be a transmission loss (into the constructions) even though the outdoor temperature is above the indoor temperature.

If you over a longer warm period experience a transmission heat loss, it can i.e. be caused by a relatively poorly insulated construction facing the virtual zone Ground, with a "fixed" low temperature. This will result in a total heat loss by transmission from the building/zone and - by the way - act like a cooling "radiator".

Data


Question:
When I try to convert a new climate data file I get the error message "*Wrong location". What do I do wrong ?

Answer:
When you get the message "Wrong location" it can be for two reasons:

1) You have not given a textual description of the contents in the climate file. This is done in the first line of the dialog.

2) You have not saved your definition file. This is done by clicking the Save button in the dialog. Doing this saves your definition file, which can be used as base for future climate data conversions, and acts as documentation of what you have done to convert your raw data.

When the conversion is finished a statistic is shown. This holds information on the parameters saved in the binary climate file (minimum-, average- and maximum-value, for each month in the converted climate file).

Question:
Does climate data exist for other locations?

Answer:
Yes, climatic data exists in BSim-format for the most European countries.

If the climate file you are looking for is not found in the BSim list of climate data files, you can try the list of climate data for the energy+ program. This list contains weather data for more than 275 locations in the USA, 55 locations in Canada and 230 locations throughout the rest of the world. These climate data are available as text files, and can be converted automatically in BSim2002 using the "File | Weather Data | ASHRAE" command while tsbi5 is active.

If you need climate data from other locations than found in the lists or available from measured data, you can try to use synthetic climate data, i.e. generated from monthly average values of climatic parameters and statistical information on the monthly variations. One source for this kind of data is METEONORM that can generate hourly climate data in a form (text), which can be converted to the binary format of BSim.

Question:
Can I create my own climate data, i.e. from measurements?

Answer:
A build-in conversion facility, converting climate data from ordinary text files (ASCII) to the binary BSim format is available via "File | Convert | Weather Data" when tsbi5 is active. It is not necessary to have climate data covering at whole year to create a BSim climate file.

You need to know at least 6 climate parameters on hourly basis to create an BSim2002 climate file. These parameters are:

  • 2 of the following 4 solar data: direct normal radiation, diffuse radiation on horizontal, global radiation on horizontal and direct radiation on horizontal. (J/cm² or W/m²)
  • The ambient dry bulb temperature (°C or °F).
  • 1 of 4 data for humidity: dew point temperature (°C or °F), relative humidity (% or fraction), absolute humidity (kg H2O/kg dry air) and enthalpy (kJ/kg).
  • Cloud cover can be given, but if not it will be calculated among others from the knowledge of the ambient air humidity. (fraction or octas)
  • Wind speed (knots or m/s).
  • Wind direction - necessary for natural ventilation simulation (°).
  • Atmospheric pressurs - necessary for single and multi zone natural ventilation simulation (Pa).
Besides this you need to know the location of the climate measuring station, meaning longitude, latitude and height above sea level.

In BSim2002 it is possible to import more than 550 ASHREA climate files directly from the Internet free of charge.


Updates

Question:
When I look at the BSim update page I see another version number of the latest database than the one I see from the programs database interface. How can I make sure I have the most recent version of the database?

Answer:
The version number of the database you see at the BSim update page is the version number of the database. The number you see from BSim's database interface (SimDb) is the version of SimDb.
To see the version number of the database, you must open the actual database file (*.mdb) using MS Access 98 and open the table "Version". The most recent version of the database always comes with the "Complete update" from the BSim update page. 
It is reccomende always to use the most recent version of the database (November 2005 = BSim2003.mdb) when starting a new project.

Question:
How can I see which version of BSim I have installed and how can I make sure that I have the most recent one?

Answer:
Click "Help" + "About BSim" to see the installed BSim version. In this dialog you can also see which extension modules you have access to.
Click "Help" + "BSim on the Web" + "Check for new update" to carry out a check if a more recent version of BSim is available at SBi's server. In the "Options" dialog (right click in the graphic) it is possible to ask BSim to carry out an automatic version check each time BSim is started. The check will only be made if there is access to the Internet when BSim starts.

Question:
I have just received information on User, Firm and Serial with the license agreement for BSims2002, but I am uncertain how to use these data during updates.

Answer:
You must use User (BSxxxx) as User name - remember to type BS in capitals - and Serial as Password (digit code). Firm is only used while installing the program for the first time. You need your serial number every time you make an update from the Internet. All information are shown at the back of the cover to your original BSim CD-ROM.

Question:
I can not update to the new version of BSim from your homepage using Internet Explorer. When I press the desired program version, I get an error message after a long waiting time. The same thing happens every time I try to update BSim. I have used the right user-ID and password.

Answer:
There can be two reasons for this problem:

1) Your Internet connection is through an ISDN connection with a time-out that shows that it hangs-up the connection while waiting for you to type your user-ID and password. In this case you get a physical new connection and our ID-checker sees you as a new user.

2) Your internet connection is via a Proxy-server with a software that do not support authorizations or if the proxy copy has not been updated as only the installation (download) file is changed, not the text.

Possible work around: You could try to download the update in pieces (program modules, User's Guide and eventually the database) if your problem is caused by the time you are connected to the Internet to download the entire program package.

Question:
When updating BSim2002 I get a question about overwriting a write-protected file. What must I answer to this?

Answer:
This question pops up when the database "SbiData.mdb" is updated. This happens when new materials or constructions are added or errors corrected.

User's Guide

Question:
The content of the help pages are not shown correct, a standard page is show, informing that the page can not be shovn correctly. What is the reason for this?

Answer:
If you have install security update 896358, security update 840315, or Microsoft Windows Server 2003 Service Pack 1 (SP1), you may experience the following symptoms: When you try use a Universal Naming Convention (UNC) path to open a Compiled Help Module file (.chm file) on a network shared folder, topics in the .chm file do not appear. These changes were introduced to reduce security vulnerabilities in HTML Help. In the Microsoft knowledge base you'll find information on how to work around this probelem. Use method 1 or 2 to work around the problem.
If you do not want to open for this security vulnerability you can either move the BSim help file (bsim02uk.chm / bsim02dk.chm) file to a local hard disk drive (e.g. C:) and open the file manually from here or you can install BSim on a local hard disk drive.

Help pages are not shown correctly even though I have made the above described changes in the Windows registry database, what is the reason for this?

Answer:
If you have downloadad the help file separately from the BSim update web-page the file have properties as if it was still located on the Internet and can thus not be opened. Locate the file bsim02dk.chm and/or bsim02uk.chm (Danish and English help file) in the folder where BSim is installed. Right-click on the file and select "Properties", press the "Remove blocking" button at the "Generel" tab - if it is visible.

Question:
I keep on getting the Danish help text when I press F1 to obtain help. I would rather have the English help text, how do I ensure that?

Answer:
If you have both help files installed, just put a tick-mark next to English F1 Help in the Options dialog from SimView. Alternatively you can delete the Danish help file, and BSim2002 will open the present help file.

Question:
I get lots of error messages when trying to open the user's guide, what is wrong?

Answer:
You need to install the upgrading for reading HTML help files from the CD-ROM. Follow the entries Updates for Windows and Update for HTML Help on the CD. This will update your operating system and fix the problem with error messages when opening the user's guide.

Question:
Is the user's guide available in a more print-friendly version, i.e. one that does not cut illustrations at the bottom of the pages?

Answer:
No, but you can use the guidelines in the User's Guide to make a readable print-out of some or all the pages. If you can not access the relevant dialog in you printer driver, you can choose to print on landscape in stead of portrait.

Miscellaneous

Question:
While simulating the temperatures in an atrium with tsbi5 it is calculated how many hours the indoor temperature is above i.e. 26 °C. This temperature in an average temperature. As the building is rather high, there must be a considerable variation from floor to ceiling. Is it possible to calculate the temperature in the living zone (i.e. from 0 to 1.8 meter above the floor) or in the bottom room of the atrium (it is divided into 5 rooms on top of each other)?

Answer:
You can use the kappa-model to calculate the vertical temperature distribution in the atrium. Input to the kappa-model is - in addition to the value of kappa - a distance from the floor where the operative temperature is calculated. The operative temperature is the temperature that all systems try to control and it is saved as Top(ThermalZone).
After simulation you can show the operative temperature in the selected height above the floor in the atrium. In tsbi5 | Tables you can select to show your results as PctCumulated or HourCumulated, which almost gives the desired result. It is though not possible to calculate the exact number of hours above i.e. 26 °C, but you can get close.

Question:
When I start a simulation in tsbi5 the program sometimes suggests a high number of time-steps per hour. What is the reason for this?

Answer:
You have probably defined a construction with a very thin material layer and maybe even with a high conductivity, i.e. some metal sheet. This will cause the program to require a high number of time steps in order to be able to make a stabile thermal simulation.

Normally you don't need to include such thin material layers in your constructions - as they play no role in the description of the thermal performance of the building. You should only simulate this kind of materials if they play a significant role in the overall thermal capacity of the building/space. If they do so, you could model this layers by manipulating the innermost layer of a construction in a way that it reflects the thermal capacity of the missing layer. (see surfaces)

In general you should not accept models that requires higher time-steps than 8-10 time steps per hour.

Question:
How do I simulate solar walls in BSim?

Answer:
It is not possible in the present version of BSim. It is though possible to cheat the program by creating a solar wall as a separate thermal zone - however this is not recommendable as some of the thermal processes in a solar wall is at a different temperature level compared to the design level of the algorithms in the building model. To secure the most correct calculation of the exhaust temperature of the solar wall, the kappa model have to be used to calculate the temperature stratification in the solar wall.

Question:
Is BSim2002 available in other languages than English?

Answer:
No, but it would be relatively simple to translate the help files to any other language - it just requires some hard work.

Question:
How do I interpret the version number of the program and the User's Guide?

Answer:
The syntax for the version number is: Main version,year,month,day. The version number is shown at the top of every page in the help text and indicates the date of the compilation of the help file. At the bottom of every help page the date for the revision of that page is shown.