Methodology
How the home energy model works
EnergyFlow turns a building description, weather file, schedules and equipment choices into a modeled year. The result is useful for comparing options under consistent assumptions. It is not a meter reading or an installation design.
1. Describe the building
Enter the house manually by floor. Construction year and house type suggest average U-values that you can review and override. CPE and plan uploads are not available in this release. EnergyFlow is for houses in France, Belgium, the Netherlands, Luxembourg, Germany, Austria and Switzerland, and the wizard asks for your country and postal code.
2. Simulate heat and comfort
EnergyPlus calculates the thermal response for modeled zones and equipment. The model runs thermal calculations at 15-minute steps, or 5-minute steps for a ground-source heat pump or a hot water cylinder heated by the main heater; public result series are hourly. A floor is represented as an aggregate zone unless a space with different conditions needs its own zone. A zone-average temperature cannot predict a particular room corner or bedroom.
3. Calculate electrical flows
Electrical dispatch calculates hourly PV, battery, EV, hot-water and grid flows using the selected equipment and tariff. Rules follow a fixed priority; the optimizer minimizes modeled energy cost. They answer different questions.
4. Compare the same assumptions
Change one input at a time to understand its effect, or compare a clearly described set of alternatives. Keep weather, schedules, setpoints and tariff the same unless one of those is the variable under study. Report delivered heat, electricity and fuel separately.
Results are estimates for the building, equipment, weather and schedules entered. Actual use also depends on installation, controls, weather and how the home is used.
Five useful simplifications
- Interior walls: partitions within a zone are not drawn individually; their effect is represented through aggregate internal mass.
- Windows: enter glazed area by exterior face and floor, with orientation, glazing properties and supported shading. Exact positions on that face are not separate inputs.
- Staircase: the opening represents air exchange between connected floors. Exact staircase location and local air currents are not resolved.
- Furniture: no furniture layout is needed. Its combined heat-storage effect is part of the internal-mass assumption.
- People and appliances: schedules and internal gains summarize use; the model does not follow occupants room by room or minute by minute.