IESVE 2023

IESVE 2023 strengthens tools to aid the drive for decarbonization and electrification, and extends energy code compliance offerings

IESVE 2023 Feature Pack 4

This new feature addresses the critical significance of indoor air quality on health, productivity, and comfort. It responds to the growing emphasis placed on indoor air quality by voluntary green rating systems such as WELL, BREEAM, LEED, HQE, as well as local building codes.

  • Export VE model data and simulated results to Octopus Labs Indalo® for an indoor air quality assessment of the concentration of pollutants and the risk of viral infection by analysing:
    • More than 900 Volatile Organic Compounds (VOCs)
    • Fine particles
    • Ozone and Nitrogen oxides 
    • Viral charge 
  • The air quality assessment provides the user with the ability to optimise:
    • Material choice
    • Ventilation strategies
  • Use the IAQ assessment to establish the risk of:
    • Viral infection transmission
    • Mould generation
  • Material properties, HVAC filtration plus the influence of local conditions via infiltration & weather data are included in the analysis
    • ApacheSystem or ApacheHVAC based models supported
    • Room groups streamline the selection of rooms for analysis
  • Detailed reportage available


Email to add this new feature to your IESVE Package. 


Indoor air quality Indalo

IESVE 2023 Feature Pack 3

NECB Code Compliance

Latest NECB extends to all Canadian provinces and territories in 2024, making this update relevant to the whole country 

  • New navigator to cover the National Energy Code of Canada for Buildings 2020
  • The new navigator includes:
    • HVAC prototype library and HVAC and SHW equipment performance updates
    • Compliance report added with new tiered performance  
    • New infiltration values and a new adjustment methodology
    • Updated envelope performance
    • Building area and space by space LPDs updated
    • Space by space LPD method for atriums has been revised
    • Interior and exterior lighting updates  

Florida Energy Code

Florida Energy Code (2023) is now brought up to date with ASHRAE 90.1 2019 PRM Integration.  FBC approval is expected in February 2024.

  • Updates to ASHRAE 90.1 2019 PRM solution to allow for compliance with the 8th Edition of the Florida Energy Code (2023)
  • New reporting has been added into the ASHRAE 90.1 2019 navigator which includes updates specific to the 8th edition e.g. mandatory provisions

Decarbonization & Electrification

ApacheHVAC: Updates to allow a Heat Transfer Loop (HTL) to pre-heat a Hot Water Loop and Domestic Hot Water. This, for example, enables pre-heat via a water-to-air heat pump

  • Heat Transfer Loop (HTL) is available as source for pre-heating of HWL or DHW using the explicit heat transfer model or simplified water-to-water heat pump
  • Recover heat rejected to HTL by water-to-air heat pumps, using that heat to pre-heat cold DHW or, via intermediary HP, to pre-heat the HWL return

HVAC modeling

ApacheHVAC: The ability to view ApacheHVAC controller outputs in VistaPro allow for new levels of analysis to be undertaken, while component browser tree improvements makes navigating ApacheHVAC outputs more streamlined

  • When selected under Output Options for ApacheSim, detailed ApacheHVAC controller outputs are available in VistaPro
    • Sensed and controlled variables, on-off status, etc.
  • Improved HVAC component grouping in VistaPro browser tree:
    • Clearer re: populated branches and multiplexed components
    • Ability to simultaneously select components or controllers across selected multiplex layers and outside of any multiplex

HVAC modeling

ApacheHVAC: New, more flexible user controls with improved defaults are provided for determining when a system air-handler cooling coil is permitted to operate

  • The logical AND connections between cooling airflow and cooling coil controllers previously included to address unnecessary coil operation have been replaced with a default configuration matching that of the most common AHUs
  • A checkbox option is provided to “Turn off AHU cooling coil when no rooms or zones require cooling or dehumidification” (unchecked by default)
  • This engages an optional On-Off control for the AHU cooling coil to prevent it cooling to an otherwise pre-determined setpoint or maximum reset (e.g., cooling mixed air to 55°F or reset SAT setpoint of 60°F) when there is no demand for cooling or dehumidification. The result is a reduction in reheat energy
  • Optional feature within ApacheHVAC

BIM Interoperability

New start page import file type GEM additions enable users to import .gem file to improve upon the Pollination (Revit/Rhino) Integration and .gsk file types via start page

  • Import into the IES VE software via the Start page > New Project > Create from BIM file.
  • Improved gbXML Export

IESVE 2023 Feature Pack 2

Code Compliance - Title 24 2022 Navigator (v1.1)

Version 1.1 of the IESVE Title 24 2022 Navigator released to comply with mid code cycle update to ACM.

  • Rule changes primarily HVAC related
  • Other changes include: 
    • The space fraction and radiative fraction used in the standard model are now based on recessed LED fixtures rather than Fluorescent
    • Update to CBECC export to include internal partitions between zones
    • Crank case heater properties in the proposed and standard model 
    • Boiler draft type in the standard model
    • Boiler efficiency in the standard model
Title 24 2022 Navigator in VE

Sunlight & Daylighting - Translucent Shades

  • The re-introduced translucent shade feature enables users to model such translucent surfaces as glass brise soleil. Meshes or lattice shading devices can also be modeled.
  • Three modeling methods are available: 
    • Construction - Transmission values are brought through from the construction and accessed as per IESVE 2019
    • Annual - A single transmission value is used for every month. 
    • Monthly - The transmission values vary on a month-by-month basis. 
Translucent Shades for Sunlight & Daylight

HWL Auxiliary Heat Source (AHS)

  • Central Plant Heat Pump (CPHP) and Simple Air-to-Water Heat Pump (AWHP) are added as a selectable Auxiliary Heat Source types downstream of the primary equipment set on the HWL. 
    • Both are alternatives to the hot water boiler and part-load heat source AHS types previously provided in IESVE 2023 Feature Pack 1.
  • Auxiliary Heat Source (AHS) connections and icons for all AHS equipment types are now displayed on the ApacheHVAC waterside graphic representation. 
  • Import button added to AHS dialog: 
    • The Import button allows users to load an existing instance of the selected model type (HW Boiler, PLC, or CPHP) from another HWL, same as that on the equipment set tab of the HWL dialog.
Auxiliary Heat Source on ApacheHVAC

Energy Meters – Hierarchy Assignment

  • Improved user assignment of meters and sub-meters
    • Same tree structure as per meter management
  • Improved user management of meters and sub-meters
    • Tree structure allows different levels of hierarchy
    • E.g. Mixed Use: Retail / Sub-leases / Apartment(s) / etc. 
  • Editing Meters:
    • Natively: Add / New / Copy / Paste
    • Externally: Import / Export to file (XML or CSV format)
    • Schema tree exported as image (PNG file)
Energy Meters in VE

Sunlight & Daylighting - RadianceIES: Grid point values added to Multiview

  • Grid point values are now displayed within RadianceIES
    • Multiview feature in ModelViewer 2 
    • For multi-floor visualizations grid values on floors concealed by the view angle are also hidden for clarity
Grid Points shown in ModelViewer

Miscellaneous – Loads Reporting

  • A table of contents (TOC) has been added to both room loads and system loads reports 
    • The TOC includes the section splits - space loads and ventilation, zone loads, room loads, etc.
  • The room and zone loads report has been updated to cater to the situation when no HVAC file exists:
    • "Supply (design)" airflow values are calculated based on Room Loads + Space Data inputs as per the Room Loads Spreadsheet
    • Both "Ventilation (requirement)" and "Exhaust (requirement)" volume flow rate is included and based on these values from Space Data
Loads Reports shown in VE

Miscellaneous - Efficiency: Model view, Browser tree and Building template manager (BTM)

A number of updates have been implemented making the VE faster and easier to use.

  • Model View: Improved model view rendering times across different applications
    • Software defaults to OpenGL 3.0
    • Substantial speed improvements 
  • Browser tree: Improved browser tree refresh rate
    • Adding space – up to 47% speed improvement
    • Removing space – up to 10% speed improvement 
    • Undo – up to 60% speed improvement 
  • BTM: Improved BTM refresh rate, when opening the BTM dialog, moving between templates and selection of tabs
    • Large model with 1000 templates - up to 80% speed improvement

Miscellaneous - Archiving projects

The VE project archives have been updated to .zip file format (previously in CAB format).

IESVE 2023 Feature Pack 1

Part L Ireland 2022 Building Regulations

  • Under the VE Compliance (UK & Ireland) application, the latest ‘Part L (2022) – Ireland (Factor update)’ option is present in the Regs dropdown menu.
  • The ‘Part L (2022) – Ireland (Factor update)’ includes the electricity factors update within iSBEMie_v5.6.
    • From Primary energy 2.08 kWh/kWh, CO2 0.409 kgCO2/kWh
    • To Primary energy 1.75 kWh/kWh, CO2 0.224 kgCO2/kWh
  • IES will continue to support the old ‘Part L (2022) – Ireland’ route, iSBEMie 5.5h.
    • Warning dialog is displayed in the user interface upon selection of the ‘Part L (2022) – Ireland’ route.

Central Plant Heat Pumps: ApacheHVAC Wizard

A new Domestic Hot Water (DHW) systems category has been added to the ApacheHVAC wizard for selection of Waterside Heating Systems .

UK Carbon Emission Factors (Install Set)

  • Sample UK National grid Carbon Factors shipped as part of the VE install set
  • The sample data is provided in Free-From Profile (FFP) as shown opposite in ApPro
  • Via the Energy Source and Meters dialog a user can assign these FFP files as hourly Carbon Emissions Factors (CEF)

MEPWorx Navigator

  • New MEPworx export navigator is accessible via the Partners section of the IESVE Navigators
  • Upon selection of ‘MEPworx export’ the navigator workflow is displayed
    • MEPworx export saves the model peak heating and cooling loads date in CSV format files that can be loaded by MEPworx

NCC Comfort Navigator

  • New NCC 2019 Section J comfort navigator is accessible via the Australia Compliance section of the IESVE Navigators
  • Upon selection of ‘NCC 2019 Section J comfort’ the navigator workflow is displayed
  • The user provides CLO and air speed settings for spaces 
  • The navigator uses PMV Ashrae 55 adaptive and air temperature to assess NCC 2019 section J comfort compliance
  • The navigator generates a spreadsheet report


IESVE Python API has been updated to enable users to:

  • Set the building rotation
    • An example script can be found via VE scripts > vegeometry >
  • Get and set the VE model weather file location
    • Scripts can be found via VE scripts > velocate>>

IESVE 2023 New Features

Take a tour of the new features below.

Central Plant Heat Pumps (CPHP)

  • All-Electric Central Plant Equipment 
  • Supply hot water or chilled water
  • Air-Source and Water-Source Heat Pumps
  • Heating Only Mode and Cooling Only Mode
  • Reversible Heating and Cooling Mode
  • Prototype systems added to airside wizard and waterside library
  • CPHPs extract heat from OR reject heat to a defined source and sink

Heat Pump Equipment Sizing

  • Unique Heat Pump Sizing Options
  • Typical Sizing Approach: Based on CHWL or HWL Peak Demand
  • Fix number of Heat Pumps and size their capacity
  • Fix the Heat Pumps capacity and size the number of Heat Pumps needed
  • Based on Minimum or Maximum outdoor design conditions (useful for very cold/hot climates)
  • Maximum heat/cool capacity at Rated Condition (for actual HP equipment size) 
  • HWL & CHWL independent (ideal heat + cool) 
  • Equipment Sizing Reports: CHW, HW, DHW

Heat Pump Water Heater (HPWH) for DHW

  • Prototype systems included
  • Air source or water source
  • Source/sink:
    • Outside Air
    • Profile Air-source
    • Profile Water-source 

Auxiliary Downstream Heating Equipment

  • Downstream Auxiliary Heat Source (AHS) as backup for the entire HWL
  • AHS supports temperature “cascade” schemes with Low-Temp HWL serving a High-Temp HWL
  • AHS can also be dedicated to one Secondary HW loop to maintain an independent loop temperature setpoint/reset (e.g. hotter water)
  • AHS can be a gas or electric equipment

Energy Meters – Hierarchy Management

  • Improved user management of meters and sub-meters
  • Useful for mixed-use and multi-tenant buildings
  • Add/New/Copy/Paste/Import/Export Functionality
  • Schema Tree may be exported as image

Hourly Carbon Emission Factors & Hourly Source Energy Factors

  • Annual hourly CEF and SEF profiles added to APACHE simulation engine
  • Hourly carbon emissions and source energy data written to Energy Reports

California Title 24-2022 Compliance

  • Certified by California Energy Commission 
  • Performance-based Compliance Navigator for New Non-Residential Buildings
  • Includes PV and Battery Rulesets
  • 3-model Solution
      1. Actual Design Model 
      2. Proposed Design Model 
      3. Standard Design Model (Baseline)
  • Multifamily Buildings - Geometry Exporter to CBECC

California Title 24 - Solar Access Roof Area (SARA)

  • Process Innovation to embed SARA Simulation into Title 24 Navigator
  • PV Systems and Battery Storage for Title 24-2022 requires SARA sizing provision (SARA)
  • Multiple solar simulations with PV panels
  • SARA Report PDF shows compliance at 70% threshold, exceptions included

Daylighting – Seasonal Foliage

  • Uses Vegetated Shade Object in ModelIT
  • Two Summer/Winter simulations & results parsed
  • Daylight factor
  • Annual illuminance
  • BRE 209 Appendix G

EU Navigator

  • Workflow Navigator for EU
  • Updates for EN12831 steady state heating load calculation and PMV Optimiser
  • Updates allow the user to modify more inputs
  • MS-excel Integrated edits available
  • The processing of ventilation gains have also been improved so that the supply air temperature can now be based off APACHE profiles


  • VE-Navigators re-grouped
  • KIVATM ground heat transfer: Initial zone warm-up temperature option 
  • New Navigator added to export heating & cooling loads to MagiCAD
  • MagiCAD script called that exports heating & cooling load data to a CSV file that MagiCAD can import

Got a question?

Our team is happy to answer any questions you have about IESVE 2023.