ies-erGON FAQs

Have you got a question that isn't covered in the FAQs below? For more information contact us.

What can I use IES-ERGON for?

The power of IES-ERGON can be applied in many situations to:

  • Model Existing Buildings for Retrofit
  • Improve Operational Building Performance
  • Verify Predicted Savings are Achieved
  • Enhanced Handovers & Soft Landings
  • LEED Monitoring Based Commissioning
  • Data-Driven Post Occupancy Evaluation
  • BREEAM Energy Prediction & Verification
  • Inform New Design Projects
  • Help Close the performance Gap
  • Model Advanced HVAC Controls
What’s new in this version of IES-ERGON?

Significant enhancements to the latest version of IES-ERGON have added:

•    The ability to compare measured data against simulated data and perform model calibration
•    A seamless two-way sync between IES-ERGON and IESVE
•    New plots in IES-ERGON for improved initial data interrogation
•    The ability to import real weather data

Do I need VE keys activated for IES-ERGON?

Yes, every team member will need to request IES-ERGON keys for their IESVE software. To request IES-ERGON keys from your IESVE software:

1.    Launch IESVE and then choose Help >> Troubleshooting and note your PIN
2.    Send your PIN to and request the IES-ERGON licence
3.    You will then receive an email back with instructions on activating the licence
4.    When activated you will be able to use the IES-ERGON linked features in IESVE

Why do I need IESVE keys to use IES-ERGON?

The IESVE licence key associated to IES-ERGON allows the FFD and APM files you have generated to be applied to the Virtual Environment and included in Apache simulations. This includes:

  • Use of FFD in ApPro and creation of Free Form profiles
  • Assignment of Free Form profiles to profile inputs in thermal templates, space data, ApacheHVAC etc
  • Simulation of models that contain Free for profiles
  • Loading and viewing of APM files in VistaPro
How do I access IES-ERGON?

Go to and login using the same details as your IES Web Account.

Where do I manage my IES-ERGON account?

To access your account, manage your IES-ERGON subscription and add/edit/remove team members go to

Is there any limit to the number of account members you can have?

No, there is no limit to the number of people you can invite to be account members. However, only one person per IES-ERGON subscription can use IES-ERGON at any one time.

What is my IES-ERGON account?

When you purchase an IES-ERGON subscription, an account is created for you on the IES-ERGON system that links your email address to the licence you have purchased. The person who initially completes the purchase is the Account Administrator. Further team members can be added via the website and you can opt to make other members an Administrator so that they have the same control. In addition to adding team members, the Account Administrator can remove team members.

Can only one person use IES-ERGON at a time?

Yes only one person can use IES-ERGON at any one time. Concurrent users are only allowed if you have purchased multiple IES-ERGON subscriptions. 

How can I renew my subscription?

You can renew your subscription in the My Account area  If your previous subscription has expired then then your new subscription will start straight away. If you subscription is due to expire soon, your new subscription will start when the old subscription expires.

Can I share my IES-ERGON projects with others?

Yes, when you have created a project on IES-ERGON you can invite any user to the project in view or edit roles. Any email address invited to a project needs be a member of an Account with an active IES-ERGON subscription. This does not have to be the Account of the project owner.

What are .apm and .ffd files?

APM = Apache Metered Data, can be imported directly into VistaPro and used for reference against simulation variables to give quick feedback on simulation model performance and used in calibration. APM can be set to a project level so it appears in context in the VistaPro variables list. It can be mapped by naming convention to existing variables to allow fast and easy comparisons with simulation results. The sample period of the APM will be set by IES-ERGON to match the project sample period regardless of initial raw data format.

FFD = Free Form Data file holds the time series data points of a channel ready to import into IESVE. It can be associated and used to generate a Free Form Profile which holds data for each time step (down to sub-hourly) and can be used as a more precise way of describing building operation within the simulation model e.g. occupancy or a scheduled load on a chilled water loop. Free Form Data files can be generated from metered data as well as from clocks, calendars and expressions in IES-ERGON. 

Do you offer support?

Yes, email and phone support is provided. The IES Support Team will be happy to assist you with any query you

What weather files can you use in IES-ERGON?

Any *.epw format simulation weather file can be imported to IES-ERGON via the Weather data tool. This will map to Channels covering standard weather file variables; Atmospheric Pressure, Cloud Cover, Dry Bulb Temperature, Dew Point Temperature, Diffuse Horizontal Radiation, Direct Normal Radiation, Downward Solar Radiation, Relative Humidity, Wind Direction and Wind Speed.