Technology
From building discovery through simulation, calibration, and client delivery. Built on an independent physics engine validated against ASHRAE Standard 140-2020.
Standard 140-2020 · BESTEST
Tested against the ASHRAE Standard 140-2020 Building Energy Simulation Test (BESTEST) suite — the same validation benchmark applied to EnergyPlus and DOE-2.
Starting with ASHRAE 90.1-2022, simulation tools must pass Standard 140 to be used for code compliance. Roovie's engine meets this bar — proprietary engine, independently validated.
Forensic audit logging with stable diagnostic tokens allows line-by-line comparison of every calculation path against ASHRAE prescribed values.
IBPSA-USA Recognized
Every software tool listed below has passed the ASHRAE Standard 140 acceptance criteria — the industry benchmark for building energy simulation accuracy. Roovie's physics engine is validated alongside the tools that power the industry.
| Software Name | Version | Last Validated | Thermal Fabric Low Mass | Thermal Fabric High Mass | Cooling Equipment | Heating Equipment | Air-Side Equipment |
|---|---|---|---|---|---|---|---|
| California Simulation Engine (CSE) | 0.926.0 | 06/30/2025 | |||||
| Carrier Hourly Analysis Program (HAP) | 6.2.0.1215 | 01/09/2025 | |||||
| DesignBuilder | 2025.1.1.003 | 03/25/2026 | |||||
| IDA ICE | 5.1.1 | 08/14/2025 | |||||
| IESVE Software | Test VE 2023 | 06/18/2025 | |||||
| Modelica Buildings Library | 12.1.0 | 09/26/2025 | |||||
| Roovie Physics Engine | 1.0.0 | 04/09/2026 | |||||
| TRNSYS | 18.06.0002 | 10/07/2024 |
Data shown as of April 10, 2026 and may be out of date. Check the IBPSA-USA ASHRAE Standard 140 Validator for the latest approved software list.
The Engine
An original heat balance simulation engine — not a wrapper on EnergyPlus, DOE-2, or any other existing engine. Written in a compiled systems language for deterministic performance with zero garbage collection.
Heat transfer through layered assemblies — walls, roofs, floors, slabs. Conduction Transfer Functions for constant-property materials. Implicit finite difference for variable-property or phase-change materials. Transient thermal mass captured at every timestep.
Interior and exterior surface convection with dynamic film coefficients. Interior: natural convection based on surface-to-air temperature difference. Exterior: wind-driven correlations (DOE2, TARP, MoWiTT, adaptive blending).
Perez anisotropic sky model. Angle-dependent transmittance through fenestration. Interior shortwave distribution via first-hit and radiosity redistribution. Shading from overhangs and fins.
Stefan-Boltzmann thermal radiation exchange between all interior surfaces via radiosity matrix with geometry-based view factors. Exterior longwave exchange with sky and ground. Sol-air temperature at exterior boundaries.
Sherman-Grimsrud model — air leakage driven by stack effect and wind pressure. Sensible and latent load split. Configurable shelter class for wind exposure.
Zone humidity ratio balance per ASHRAE Handbook of Fundamentals. Infiltration latent loads. Occupant and equipment moisture generation. Surface condensation and mold growth risk assessment.
Every timestep, the engine solves all six physics modes simultaneously — not sequentially. Circular dependencies resolved through iterative convergence: ≤15 iterations per timestep, ε = 0.05 K. Adaptive sub-stepping per ASHRAE 140-2020 Annex B.
Compiled systems-language engine — no interpreter, no garbage collection, deterministic memory at every timestep. REST API with multi-tenant support for organization and user scoping.
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Concurrent simulations
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Minimum timestep
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Hours per simulation
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Desktop installs required
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Garbage collection pauses
Workflow
Enter a building address. The platform geocodes the location, identifies the ASHRAE climate zone, and extracts building characteristics. Select the footprint from map data or draw a custom polygon. Configure floors, height, area, orientation, and window-to-wall ratio. The building renders as an interactive 3D model with auto-generated thermal zones.
33+ building types · Climate-aware from first input
Every wall, roof, floor, and window assembly is defined as a layer stack with full thermal properties. U-values and R-values are calculated from actual material properties. The Assembly Design Agent recommends constructions based on climate zone and building type across four tiers: Code Minimum, High Performance, Premium, and Custom.
Fenestration: U-value, SHGC, visible transmittance, angle-dependent behavior
U-value: — BTU/hr·ft²·°F
R-—
People, lighting, and equipment loads defined per zone with radiant/convective splits. 24-hour schedule profiles for weekdays, weekends, and holidays. HVAC systems designed and sized through the HVAC Design Agent — from load calculation through equipment selection, zoning strategy, and control configuration.
System types: Ideal loads · Unitary · VAV · VRF · Boiler/Chiller plant
Weekday · Office Occupancy
Select a weather file. Configure the run period and timestep. The platform validates readiness before launch. Simulations run in the cloud with real-time progress. Results: annual energy by end use, EUI, peak demand, cost by fuel type, carbon emissions (Scope 1 and Scope 2), and CBECS benchmarking.
Upload 12 months of utility bills · Month-by-month variance tracking · Calibration factors transferable across similar buildings
The Platform
Explore every zone, surface, and assembly in 3D
Select zones to inspect thermal properties and HVAC assignments
Multiple camera presets — front, side, top, isometric
Annual energy split by heating, cooling, lighting, equipment, fans, and DHW
Peak demand pinpointed to the exact hour of the year
CBECS benchmarking against national data for the same building type
Total: 6,630 MWh/yr | EUI: 74.2 kBtu/ft²·yr
Clients see buildings, results, and reports in their own portal
Drag-and-drop report builder with charts, tables, and calculation provenance
Shared links with password protection and expiration
Business Impact
For MEP firms and energy consultants, ECM analysis is where the money is — it's the deliverable your clients pay for.
Create measures. Define energy conservation measures with first cost, maintenance, lifetime, and applicable building types. Categories: lighting, HVAC, insulation, windows, controls, renewables.
Run full simulations. Each ECM runs as a complete simulation — not a percentage adjustment. Compare against the calibrated baseline: energy savings, cost savings, carbon reduction, simple payback, and ROI.
Stack and compare. Run LED alone, then LED + VFDs, then LED + VFDs + envelope upgrade. See the real cumulative effect — including where measures overlap.
| Measure | EUI | Savings | Payback |
|---|---|---|---|
| Baseline | — | — | — |
| LED Retrofit | — | —/yr | — yrs |
| LED + VFD | — | —/yr | — yrs |
| LED + VFD + Envelope | — | —/yr | — yrs |
Your team delivers physics-based upgrade recommendations, not rules of thumb. Every savings number is backed by a full simulation run.
Business Impact
Manual report assembly is unbillable overhead. Automating this step is a direct profitability improvement.
Report builder. Drag-and-drop layout with configurable widgets: text, charts, tables, metric cards, images, equations, and simulation comparison tables.
Templates. Pre-built templates or custom organization-level templates for consistent deliverables across projects.
Export and share. Styled PDF reports. Batch-generate for building groups. Shared via secure links with password protection and expiration.
The report is a byproduct of the simulation — not a separate multi-day effort.
Energy Audit Report
EUI
74.2
Annual Cost
$312K
Business Impact
The portal turns Roovie from a tool your modelers use into the platform your firm delivers through.
Client intake. Clients submit projects through configurable intake forms with status tracking.
Client dashboard. Active projects, shared buildings with 3D models, simulation results, and reports.
Building intelligence. Interactive 3D viewer with seven tabs: overview, documents, simulations, zones, HVAC, assemblies, materials.
Simulation comparison. Baseline vs. ECM results with interactive thermal visualization.
Communication. Bidirectional document sharing and real-time messaging.
Intake Form
Project submitted
Under Review12 fields · Utility data attached
400 Dallas Street
3D Model · 4 Zones · 12 Assemblies
Energy Audit Report
Shared Link · Password Protected
Expires May 1, 2026
Your clients get a portal experience. You get leverage. Every building you model becomes a living asset your client can revisit — not a PDF that disappears into a folder.
Advanced
Photovoltaic Arrays
Rated power, tilt, azimuth, tracking, temperature derating, inverter efficiency
Solar Thermal
Collector area, optical efficiency, thermal loss, fluid flow
Battery Storage
Capacity, chemistry, round-trip efficiency, depth-of-discharge
Combined Heat & Power
Electric + thermal output, dispatch modes
Kusuda-Achenbach deep-ground temperature model for slab-on-grade floors. Configurable soil properties and slab geometry. Steady-state and periodic ground response models. ASHRAE 140 GC periodic cases (GC40b–GC80c) validated with multi-year convergence.