January 29th 2025

IESVE Australasia Summer School: Answering Your Questions

IESVE Australasia Summer School: Answering Your Questions

Late last year, IES ran a series of lecture-style sessions covering key analyses that can be undertaken using IESVE. With over 100 questions submitted across the sessions, addressing each one wasn't feasible. However, common themes emerged within the questions asked, and so to tackle these questions, we turned to Roger Cladingboel, our Vice President for Australia and New Zealand.

Read on for the answers to these questions, where Roger shares invaluable advice on how IESVE can be utilised across a wide variety of key analysis areas.
 

Geometry

What is the purpose of a perimeter zone?

A perimeter zone allows for quick automated zoning. For more information, read our blog on Zoning Your Models.

How do I change the scale of a drawing within IESVE if the geometry is not to scale?

If you would like to change the geometry scale, you can the button illustrated below.

If you would like to change the DXF scale, this is done during the DXF import in ModelIt, which is illustrated below.

Is the computational grid only able to be cartesian (rectangular)? Or can it be more generic polyhedral?

The grid is fixed to a rectangular grid.

For energy modelling, do we use model with volume, or just the boundary?

Energy modelling is calculated based on air volumes. Models should be created to the inner line of the external construction.
 

Energy Simulation

What kind of data is needed to run an energy simulation?

At a minimum, you need:

  • A weather file
  • Relevant Apache systems
  • Constructions
  • Building thermal templates
  • Heating and cooling set points
  • Healthy model geometry
  • Air exchanges
  • Natural ventilation
  • External gains

Do you model an open space as a room which is naturally ventilated, or model it as a void?

You can model it as a room with natural ventilation, either using air exchanges or MacroFlo.

Which module within IESVE predicts the thermal comfort levels in each zone?

Apache/VistaPro predicts the thermal comfort levels in each zone using ASHRAE 55 or CIBSE TM52 criteria and methodologies.

When we use infiltration value for voids, is it infiltration from the conditioned space or infiltration from outside ambient air?

All infiltration can be based on the adjacent spaces connected (outside ambient air and conditioned) and can be specified under the air exchanges within the model.
 

Daylight and Solar

Can you choose a landscape for the building? As in a grassy landscape or a mountain landscape or a winter landscape, etc?

You can only visually change landscaping in ModelViewerII. However, you can change the ground solar reflectance to match the surroundings. This is done under APLocate, which has the button illustrated below.

Can you generate a glare compliance report?

There is no automated compliance report for glare analysis. However, you can use RadianceIES to carry out glare analysis.

Can you add solar panels on the roofs and calculate the electricity generated from these?

Yes - by using the button illustrated below found on the ModelIT toolbar, or via the renewables in Apache.

 

Can we add in effect of a motion sensor or factor in other controls systems while doing daylight modelling?

Yes, this can be done using the query tool or tabular space data under Apache. You can also link RadianceIES to Apache to carry out daylighting control based upon the weather data file used.
 

Heating and Cooling Loads 

Is it important to create the exact real-life profile for internal gains and HVAC? 

It is important to create a profile as close as possible to real-lie to produce the most accurate results. Many template profiles can be found and applied already using AP profile database manager.

Is it possible to create custom systems as per individual project requirements?

This is possible under Apache systems and ApacheHVAC.

Is it possible to size the chilled water pumps considering the heat losses in the piping and other components (such as valves etc.)?

Components of the pipe work system are not modelled. Further information on chilled water pumps can be found here.

Can the software show ETTV and RTTV values?

This is possible. For more information, visit our help site.
 

HVAC Systems

What's the difference between the heating set point and the HVAC zone heating set point? Can I change the HVAC zone heating set point in ApacheSim?

The heating set point is for the entire system whereas the HVAC zone heating point is for that specific system. You can change the heating setpoint on a room-by-room basis.

What are the capabilities or limitations with respect to system/plant design in IESVE?

Under ApacheHVAC the limitations are determined by your own systems specifications. There’s no upper threshold. Detailed System Modelling: IESVE's ApacheHVAC module supports detailed modelling of various HVAC systems, including VAV, CAV, fan coil units, heat pumps, and more. You can define custom configurations, controls, and even model undersised equipment to analyse system performance.

  • Waterside Plant Modelling: Model hot water and chilled water loops with pumps, boilers, chillers, cooling towers, and economisers. The software accounts for equipment sequencing and off-design loop temperatures.
  • Airside Plant Modeling: Model air handling units, fans, coils (heating and cooling), heat recovery devices, humidifiers, and ductwork with thermal properties.
  • Room Units: Include terminal units like radiators, chilled beams, and direct-acting heater/coolers within your models.
  • Performance Curves: Access a library of performance curves for plant equipment or input your own data.   
  • Zone and System-Level Sizing: Automate the sizing of HVAC components based on either zone-level loads or a full system-level dynamic simulation to meet design loads.

ApacheHVAC is not a pipework or ductwork sizing tool, and is for energy and system performance analysis.

Apart from the heating (heat pump/boiler) and the cooling (chiller) systems, can energy recovery systems be modelled within IESVE?

Basic Heat recovery can be taken into account in Apache Systems, but can be modelled with more accuracy in ApacheHVAC.
 

CFD Airflow Simulation

Do we always assume that the flow will be turbulent? Will there be instances in which the flow is laminar, and if yes, which model should we use if not k-e?

Yes, it's unlikely laminar flow will be present due to the large air volume in the room between the inlet and outlet.

Can MicroFlo and MacroFlo be enabled together to see the effect of external flow on internal air velocity inside room?

You can bring results from MacroFlo into MicroFlo to be studied.

After the CFD simulation, will the result be presented in a report like the energy simulation?

The results are not within a report, as these are visual results overlaid into the space. You can then inspect and export these visually and numerically as you wish.

How do we add heat sources, humidity and CO2 sources within a zone inside the CFD model? Can you change the underlying solver settings and boundary conditions?

These both are covered under our on-demand training.
 

BIM Interoperability

Can we import models form other software applications into IESVE?

We can import models from SketchUp and Revit via GBXML. To import models from Rhino, you would need to purchase the Pollination plugin, which can also be used to import models from Revit to the VE. You can find a list of all 3rd party software we currently support here.

Can IESVE support files from other software such as EnergyPlus, TracePro or SolidWorks?

IES does not link with or import models from Energy Plus, TracePro and SolidWorks.

Can I populate the spaces properties or zone settings in Revit and get the information in IESVE, or do I need to reapply in IESVE?

The data that can be brought over from Revit includes: Building Location, Building Type, Building constructions/fabric, Room names, Room type, Occupancy (Heat gain/person), Electrical (Lighting & Power loads), Zone data (Heating & cooling set points). The level of data varies depending on whether you place rooms or spaces to capture your model geometry.

Is there a key checklist to check or best practices to go through before exporting files from Sketchup/REVIT to IESVE, like no open rooms, all walls to have ceilings, etc?

Yes, we have a BIM Import Navigator that provides a checklist for external geometry imports. We also have prepared user guides for SketchUp and Revit importing. 

Is it possible to integrate Indalo Indoor Air Quality simulations into IESVE to use MacroFlo and MicroFlo to investigate the impacts of changes in indoor temperature, humidity, wind pressures, wind flows and air leakages on indoor air quality?

Yes, through IES' partnership with INDALO®, detailed Indoor Air Quality analysis can be undertaken using VE model constructions and dynamic simulation results file. INDALO® is not native to the IESVE and needs a separate licence to access the navigator. For more information on using INDALO® with IESVE, visit here
 

Weather

Can you modify sky condition files to reflect local conditions?

You can change the ground solar reflectance to match the surroundings, however you cannot edit or manually input weather file data. You would need to source a weather file that is local or representive of the site in question. IES have a selection of weather files, which can be found here.

Can you apply a rainy condition outside of the building?

Rainy days cannot be simulated.
 

About IESVE

Is there a Student Handbook for using IESVE?

IES have developed a Student Handbook for students, educators and professionals alike, to act as a lifelong technical aid to help portray the technical fundamental concepts of building science with the art of Building Performance Modeling. This can be accessed here.

How many minimum cores are required in my PC for simulations?

We would recommend a dual-core CPU, so that one core can cope with background tasks (such as antivirus etc.).

A suggested specification would be:

Want to discover more about IESVE?

Contact Roger Cladingboel for more information, or visit our website.