Vabi vs Hysopt
From load calculations to complete HVAC system simulation
Vabi is widely used for heating and cooling load calculations and compliance-related studies. Hysopt takes the next step by transforming load data into complete HVAC system design, simulation and optimisation — helping engineers validate hydraulics, controls and real-world system performance before installation.
What is the difference between Vabi and Hysopt?
Vabi is widely used for heating and cooling load calculations and compliance studies. It provides the static demand figures engineers need in the early design stages.
But load calculations alone don't guarantee that an HVAC system will perform efficiently once installed.
Hysopt builds on those calculations by modelling the entire HVAC system. Engineers can simulate hydraulic behaviour, validate control strategies and optimise performance before construction starts.
Discover how consultancy firm Becks moved from Vabi to Hysopt 🡢
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Why engineers extend their Vabi workflow with Hysopt
1. Move beyond load calculations
Vabi provides the starting point. Hysopt helps engineers design and validate the HVAC system that must deliver those loads in practice.
2. Validate system behaviour before installation
Engineers can test hydraulics, balancing and controls before construction begins, reducing risk during commissioning.
3. Improve operational performance
Hysopt helps optimise system efficiency, comfort and energy performance through dynamic simulation and analysis.
When does Hysopt add value alongside Vabi?
Detailed HVAC design projects
When load calculations need to be translated into complete HVAC system designs.
Commissioning and handover phases
When engineers need confidence that systems will perform as intended after installation.
Energy optimisation projects
When HVAC performance needs to be improved beyond static design assumptions.
Want to turn load calculations into validated HVAC system performance?
Discover how Hysopt helps engineering teams move beyond static calculations with dynamic HVAC system simulation and optimisation.
How teams use Vabi and Hysopt together
Many engineering teams use Vabi and Hysopt as complementary tools throughout the design process.
A common workflow starts with load calculations in Vabi. Those results are then used in Hysopt to design, simulate and optimise the HVAC system before installation.
With Hysopt, teams can:
• Build complete HVAC system models
• Simulate hydraulic and thermal performance
• Validate control strategies
• Compare design scenarios
• Generate performance reports for stakeholders
Frequently asked questions
What is the difference between Vabi and Hysopt?
Does Hysopt replace Vabi?
Can Hysopt perform heating and cooling load calculations?
How does Hysopt reduce HVAC oversizing?
Can Hysopt validate HVAC system performance before installation?
Ready to go beyond load calculations?
See how Hysopt helps engineering teams transform Vabi load calculations into HVAC systems that are balanced, controllable and designed to perform in practice.
Still comparing?
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Discover our innovative simulation and calculation software, completely tailored to HVAC engineers.
Join the ranks of leading professionals already using Hysopt to deliver remarkable results.
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