h2x vs IESVE
This h2x vs IESVE comparison examines how both platforms handle heating and cooling loads, HVAC system design, automatic sizing, duct and pipework, energy modelling, BIM workflows and engineering outputs.
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h2x vs IESVE: The short answer
h2x and IESVE both support detailed building load calculations and HVAC engineering, but they are designed around different priorities.
h2x connects calculated building loads directly with detailed HVAC and wider MEP system design, with values automatically feeding system sizing as the design changes. IESVE provides a broader building-performance environment for HVAC simulation, annual energy modelling, sustainability and environmental analysis.
The main difference is focus: h2x is built around connected MEP design and project delivery, while IESVE goes deeper into whole-building performance simulation.
Choose h2x if:
You want building loads connected directly with detailed HVAC and wider MEP design, automatic system sizing and project outputs.
Choose IESVE if:
Your priority is whole-building energy modelling, HVAC simulation, sustainability or environmental performance analysis.
What are h2x and IESVE used for?
h2x is cloud-based MEP design software for mechanical, plumbing and fire engineers. It connects building load calculations with system layouts and automatic sizing, keeping calculations and designs in sync as project changes are made. The same workflow also carries calculated systems through to exports.
- Heating and cooling load calculations
- ASHRAE 183-compliant load calculations
- Connected HVAC layouts and automatic sizing
- Detailed ductwork and hydronic pipework design
- Mechanical, plumbing and fire workflows
- Fan and pump duty calculations
- 2D and 3D design review
- PDF, BOM, AutoCAD and Revit outputs
IES Virtual Environment (IESVE) is building performance modelling software for HVAC design, energy analysis, compliance and environmental studies. Its applications share a central building model, with the APACHE engine providing core thermal and building performance simulation.
- Heating and cooling load calculations
- ASHRAE Standard 183 workflows
- HVAC system and equipment sizing
- Dynamic HVAC and controls simulation
- Annual energy and carbon modelling
- Specialist duct and pipe design applications
- Daylight, natural ventilation and CFD analysis
- BIM and regulatory-compliance workflows
h2x vs IESVE comparison table
| Comparison area | h2x | IESVE |
|---|---|---|
| Product overview | ||
| Primary purpose and best fit | Detailed MEP engineering design connecting building loads with system layouts, calculations, automatic sizing and project outputs. | Integrated whole-building performance modelling covering loads, HVAC, energy, compliance, sustainability and environmental analysis. |
| Engineering scope | Mechanical, plumbing and fire design, including heating, cooling, ventilation, ductwork, hydronic systems, domestic water, drainage, gas and fire protection. | Building performance, HVAC, energy and environmental analysis, with additional specialist applications available for ductwork and hydronic pipework design. |
| Platform and access | Cloud-based platform accessed through a supported web browser; internet access is required. | Installed desktop software requiring the VE applications to be downloaded, installed and activated with an IESVE licence. |
| Loads, standards and system design | ||
| Calculation methods | Supports regional heating and cooling load methods and standards, including CIBSE methodologies, ASHRAE 183-compliant peak load calculations and EnergyPlus Heat Balance workflows for heat gain and cooling loads. | Uses the APACHE simulation engine and supports methods including ASHRAE Heat Balance, CIBSE Admittance, ANSI/ASHRAE/ACCA Standard 183 and ISO 52000. |
| Heating and cooling loads | Room-by-room heat loss and heat gain calculations connected directly with detailed system design and sizing. | Heating and cooling load calculations for rooms and zones, with calculated loads available for HVAC system and equipment sizing. |
| ASHRAE Standard 183 | Complies with ASHRAE Standard 183 for peak heating and cooling load calculations, including hourly analysis, weather data, detailed inputs and reporting. | IES states that IESVE meets or exceeds ANSI/ASHRAE/ACCA Standard 183 requirements using the ASHRAE Heat Balance Method. |
| CIBSE Software Verification | Currently listed on CIBSE's Software Verification Assessment register for Air Systems, Domestic Water Systems and Heating & Cooling Water Systems. | IESVE is not currently listed on CIBSE's Software Verification Assessment register. IES separately documents support for CIBSE methods and CIBSE TM33. |
| Connected load-to-HVAC design | Calculated building loads feed directly into HVAC design, where they are automatically used for system sizing and the calculations remain in sync as the design changes. | Peak building loads can feed directly into ApacheHVAC for system and equipment sizing without manual re-entry. Detailed distribution design is handled through specialist IESVE applications. |
| Ductwork design and sizing | Engineers can draw ductwork directly on the project layout, with values from building load calculations automatically used to calculate duct sizes, airflows, pressure losses and fan duties. | Available through the specialist IndusPro application, which supports graphical ductwork design, automatic sizing, airflow, pressure loss and fan duty calculations. IESVE is more broadly positioned around building performance and HVAC analysis. |
| Hydronic pipework design | Engineers can draw hydronic pipework directly on the project layout, with building load calculations feeding into pipe sizing, flow rates, velocities, pressure losses, index circuits and pump duties. | Available through the specialist PiscesPro application, which supports graphical hydronic pipework design, sizing, flow and pressure calculations, balancing and pump requirements. This is a specialist capability within the broader IESVE suite. |
| Plumbing and fire protection | Supports domestic water, drainage, gas and fire protection design alongside mechanical and HVAC systems. | Current IESVE product information focuses primarily on building performance and HVAC rather than equivalent domestic water, drainage, gas and fire protection design workflows. |
| Building performance and analysis | ||
| Annual energy and carbon modelling | Currently focused on building loads and detailed system design rather than whole-building annual energy and carbon simulation. | Supports detailed annual building energy, carbon, cost and HVAC performance simulation using the IESVE building model. |
| Environmental performance analysis | Supports ventilation system calculations and design, but whole-building daylight, natural ventilation and CFD simulation are not core h2x workflows. | Supports specialist environmental analysis including daylight, natural ventilation, bulk airflow and CFD through applications such as RadianceIES, MacroFlo and MicroFlo. |
| Compliance and sustainability | Supports system specific regional and international engineering standards rather than whole-building energy code and sustainability certification workflows. | Provides extensive building energy compliance, regulation, certification and sustainability workflows across multiple global standards and rating systems. |
| Project delivery | ||
| CAD and BIM interoperability | Exports calculated system designs to AutoCAD and provides one-way coordination into Revit, with supported system components mapped to company families and BIM content. | BIM Navigator supports workflows including Revit, gbXML and IFC, with geometry and project data able to be updated as the design evolves. IESVE also supports DXF and other model exchange workflows. |
| Project outputs | PDF drawings, heat load reports, calculation reports, sizing reports, Bills of Materials, schedules, AutoCAD and Revit outputs. | Extensive load, HVAC sizing, energy and simulation reports in spreadsheet, PDF and visual formats. Specialist duct and pipe applications can also produce system and parts information. |
| Collaboration and design sharing | Browser-based sharing allows teams, clients and stakeholders to review current project information without transferring local project files. | Uses a desktop project workflow, with BIM interoperability and model exchange supporting collaboration and coordination between architects, engineers and other project teams. |
| Evaluation and pricing | ||
| Implementation, training and support | Browser-based setup with guided demonstrations, live training, self-service learning resources and 24/7 support from the h2x team. | IES provides training, documentation and technical support, while advanced workflows may require more specialised IESVE knowledge and experience. |
| Evaluation and pricing | Free project, demonstration and guided-evaluation options are available. Pricing is provided through a tailored quotation based on team size and required capabilities. | A fully featured 30-day free trial is available. IESVE Professional and Expert packs are priced by quotation, with licensing and available seats depending on the selected package. See the IESVE packs page for current package information. |
Note: IESVE information on this page was last checked against publicly available IES product documentation in September 2026.
Where h2x and IESVE differ
Both platforms can calculate building loads and support HVAC engineering. The biggest difference is how far each platform extends beyond those calculations and how the wider workflow is structured.
Loads linked to system sizing
h2x automatically uses calculated building loads to size detailed HVAC and wider MEP systems, keeping the calculations updated as the design changes. IESVE can feed building loads into HVAC sizing and simulation, with greater emphasis on whole-building performance analysis.
One workflow vs broader simulation suite
The 2D and 3D views shown above are both from h2x, where system design, sizing and engineering outputs sit within one focused MEP project. IESVE integrates specialist applications around a shared building model, extending into energy, compliance and environmental simulation.
Wider MEP vs environmental analysis
h2x extends beyond HVAC into domestic water, drainage, gas and fire protection within the same connected design workflow. IESVE goes further into whole-building energy, carbon, daylight, natural ventilation, CFD, comfort and sustainability analysis.
Project delivery vs performance analysis
h2x carries calculated MEP systems into PDF drawings, sizing reports, Bills of Materials and AutoCAD/Revit workflows. IESVE goes deeper into dynamic simulation and building performance analysis for evaluating energy, carbon and environmental outcomes.
Should you choose h2x or IESVE?
The better option depends on whether your priority is detailed MEP system design and project delivery or advanced whole-building performance modelling and simulation.
Verdict: h2x is the stronger fit for teams that want building loads connected directly with detailed HVAC and wider MEP system design, automatic sizing and project outputs. IESVE is the stronger fit where advanced whole-building energy modelling, HVAC simulation, sustainability and environmental performance analysis are the primary requirements.
Why teams choose h2x over IESVE
IESVE is a powerful building performance suite with extensive capabilities for HVAC simulation, energy modelling, compliance and sustainability analysis.
h2x takes a more focused approach for MEP engineers by keeping calculated building loads connected with detailed system layouts, automatic sizing and project outputs throughout the design process.
Heat loads to system design
Take room-by-room heating and cooling loads directly into ductwork, pipework and equipment sizing, with calculated values remaining connected as the engineering design changes.
Connected HVAC and MEP sizing
Draw detailed HVAC systems and automatically calculate duct sizes, pipe sizes, airflows, pressure losses and fan or pump duties within the same project workflow.
Generate PDF drawing sets
Turn the latest calculated system design into professional PDF drawings for project documentation, keeping layouts and engineering information connected through to delivery.
What teams say about h2x
h2x vs IESVE frequently asked questions
Ready to see how h2x can work for your team?
Book a demo to see how h2x connects heating and cooling loads with detailed HVAC system design, automatic duct and pipe sizing, wider MEP workflows and professional project outputs.
