SystemSimulator – the free online building‑thermodynamics simulator
Model any building or campus and analyze energy usage with real‑world weather data
Model any building
Worldwide weather data
Include renewables



Quickly build any structure
SystemSimulator is powerful enough for auditors yet simple enough for enthusiasts. Engineers and developers are also welcome to use SystemSimulator to develop new and improved Halo/S™ algorithms that help reduce global energy consumption.
Create any building—from a one‑room apartment to a 100‑plus‑floor skyscraper—and account for everything from window coverings to shade trees. Using hourly weather data from more than 90 climates worldwide, the software solves full thermodynamic differential equations each minute of the year, delivering energy‑use estimates accurate to the cent. SystemSimulator can accurately simulate the impacts of both construction design and thermostat‑control algorithms.
Create any building—from a one‑room apartment to a 100‑plus‑floor skyscraper—and account for everything from window coverings to shade trees. Using hourly weather data from more than 90 climates worldwide, the software solves full thermodynamic differential equations each minute of the year, delivering energy‑use estimates accurate to the cent. SystemSimulator can accurately simulate the impacts of both construction design and thermostat‑control algorithms.

Chart and optimize
Every simulator parameter can be charted, providing an unprecedented view of energy flows within a building.
Comprehensive feature list
- Calculate the energy savings from home improvements
- Analyze energy‑cost trends across different climates and building types worldwide
- Measure precise energy savings using new thermostat‑control programs
- View seasonal energy‑usage changes to plan ahead






