Simulation Manager

The DesignBuilder Simulation Manager (SM) allows you to run and control multiple parallel simulations and access the results. Some advantages of using the Simulation Manager are:

• It allows you to run multiple simulations in parallel on your local machine, on a local network machine or on the cloud using the JESS online system, while you continue to work on your model or close the DesignBuilder application down.

• A single user interface is used for displaying and managing all of your simulations and see their progress and status.

• Access the model and continue with your DesignBuilder work while the simulations run.
• Access to 64-bit versions of EnergyPlus which can run larger models and execute much faster for large models compared with the 32-bit DLL versions, which are used when running EnergyPlus directly in DesignBuilder without the Simulation Manager.
• Convenient way to store, access and compare simulation results, either via the Results Viewer or by loading results into the main DesignBuilder application.

Note: Design optimisation, ASHRAE 90.1 Appendix G PRM and UK DSM simulations are always run using the Simulation Manager to take advantage of the parallel simulation capability, giving you the fastest possible simulation times.

Use Simulation Manager

To run an EnergyPlus simulation using the Simulation Manager go to the Simulation Manager tab on the Simulation Calculation options dialog and check the Use Simulation Manager checkbox. This shows further data items described below.

The Simulation Manager can also be accessed from the Optimisation Calculation options dialog.

Server

By default the localhost server is selected, which is the option to use the Simulation Manager installed on the local machine. Choosing this allows you to run and control simulations from DesignBuilder, continue to work on the model or another model or even close DesignBuilder down and the simulations will continue to run unaffected. If the local machine is put into hibernate or sleep then the simulations will be suspended too and will resume when the machine is switched on again. If the machine is shut down while simulations are running then those simulations will be lost but should start again (from the beginning) when the machine is started up again.

Another option is to select a server on a different machine on the network from the drop down list. To enable other servers to appear on the list for selection you should first follow the steps on the Install Simulation Server page. When running simulations on a server, as well as the advantages already mentioned above for the localhost, you can also:

• Close your machine down and the simulations will continue to run unaffected. You must of course be connected to the server over the network to start the simulation and to retrieve results, but the connection can be disconnected while the simulation runs.
• Frees the machine running DesignBuilder giving it more processor and memory resources for the input file generation process, which further reduces the overall wait time for results.

Note: If the selected server is not available for any reason, DesignBuilder will revert to using the first server on the list of active servers, typically localhost. This can happen when, for example, a simulation model set up by modeller A to run on a dedicated simulation server is sent to a modeller B who does not have access to that server.

Tip: With a good internet connection at both ends and a VPN service you can run simulations on an office network server from your laptop when away from the office. Note that in this case there will be a transmission overhead as input files are uploaded to the server and results are downloaded. This is of course more of an issue for larger models, especially when large datasets are generated.

Dedicated Simulation Servers

 

Some advantages of using a dedicated simulation server for your EnergyPlus simulations are:

 

• You can close the computer running DesignBuilder down once the job is submitted and the simulation(s) will continue to run. This can be especially useful for long simulations. Results can be retrieved later by opening the Simulation Manager dialog.
• If you choose a powerful multi-core server with plenty of memory you can run many simulations more quickly and simultaneously.
• The processor of the computer running DesignBuilder doesn't get overloaded while you are working on the model.

Tip: You can obtain a high-performance simulation server configured and ready to run from Ensims.

EnergyPlus server method

There are 2 options:

• EnergyPlus - the default option where the Simulation Manager runs EnergyPlus directly. When this option is selected you will see a progress bar for each simulation in the SM dialog.
• JEPlus - select this option if you have an account on the JESS online service and would like the Simulation Manager to run simulations via JEPlus and the JESS server. When this option is selected, an "indeterminate" progress bar is used for each simulation in the SM dialog because the SM does not know the actual percentage progress of the simulation on the JESS server until the simulation is complete.

Accelerate

When the JEPlus EnergyPlus server method is selected, you can choose to speed up annual simulations using a special build of EnergyPlus where all 12 months are simulated in parallel at the same time. Running "split simulations" in this way can save a lot of time for large models. Time savings can be up to 10X for large models, but are usually smaller than this due to the overheads involved in each simulation (preconditioning, autosizing, copying files etc). For small models you are unlikely to see any worthwhile benefits in using this option.

Important Warnings

 

1. The accelerated version of EnergyPlus will produce slightly different results compared with simulations run without the Accelerate option selected. This is because each month is simulated separately and therefore the building thermal mass does not include an accurate history of heat stored from the previous month. When the Accelerate option is not selected the results produced by JEPlus match exactly with those generated when using the EnergyPlus server method.
   
   
2. Particular cases where the Accelerate option should not be used include:
   
   
   1. Buildings with high levels of thermal mass.
   2. Models that include ground heat exchangers where the evolution of ground temperatures must be retained from previous months in the simulation.
   3. Models that use ground domain objects, for similar reasons to above.
   4. Simulations where adaptive comfort outputs are required may be affected.
      
      
3. A reduced selection of summary outputs are generated for the accelerated version and are formatted differently.
   
   
4. TM52 and TM59 calculations are not supported by the accelerated option.

Version of EnergyPlus

The version of EnergyPlus to be used in all simulations is set on the EnergyPlus tab of the Program options dialog. The Simulation Manager will choose the appropriate version of EnergyPlus given the version number selected. If the machine on which the simulations are to be run is running a 64-bit Windows OS then the 64-bit version of EnergyPlus is used, likewise if it is a 32-bit version of Windows then the 32-bit version of EnergyPlus is used.

Note: Access to 64-bit versions of EnergyPlus is one of the reasons for using the Simulation Manager. Otherwise, when not using the Simulation Manager, the 32-bit DLL version of EnergyPlus is always used. 64-bit EnergyPlus should generally be used for large models as they run much faster and are less likely to fail due to insufficient memory being available.

See also:

• Simulation Manager Dialog
• Installing the Simulation Manager on a Server