Building Energy Forecasting via Physics-Based Thermal Model

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Solution Overview

Problem

Current methods for predicting energy consumption in buildings are either data-intensive and limited by artificial intelligence approaches or oversimplify physical phenomena, leading to unsatisfactory results.

Innovation Solution

A method that incorporates a physical model accounting for heat exchanges, passive solar contributions, internal gains, and thermal losses, using a learning process to determine model parameters from past measurements, allowing for precise forecasting of energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a neural network method is used to analyze measured values and data, then future forecasts can be made, but the method requires a large amount of data, is long to develop, and requires complex calculations

Engineering Contradiction:
Improveforecasting accuracyVSAvoidcalculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the neural network artificial intelligence approach with a physics-based thermal model. Instead of using complex data-driven algorithms that require extensive training data and computational resources, the invention uses fundamental thermal physics equations (heat balance, conduction, convection, radiation) to predict energy consumption. This substitution of mechanical/physical principles for computational complexity directly resolves the contradiction by achieving accurate forecasts through simpler, more interpretable physical laws.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the approach by changing from analyzing raw measured values through neural networks to using physics-based parameters (thermal conductivity, heat capacity, U-values, solar gains) in a structured thermal model. This parameter transformation allows the system to achieve forecasting accuracy while reducing computational complexity and eliminating the need for extensive historical data training.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If physical phenomena are modeled with major simplifications, then calculation means are reduced, but heat exchanges with the exterior are neglected leading to unsatisfactory results

Engineering Contradiction:
Improvecalculation simplicityVSAvoidforecasting accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the thermal model into distinct physical components: conduction through building envelope elements (walls, roofs, floors), convection at interior and exterior surfaces, radiation exchanges (including solar gains), and infiltration/ventilation losses. By dividing the complex thermal system into these manageable segments, the model maintains calculation simplicity while capturing all major heat exchange mechanisms, thus resolving the contradiction between model simplicity and accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces thermal resistance (R-values) and thermal conductance (U-values) as intermediary parameters that simplify the representation of complex heat transfer processes through building assemblies. These intermediary parameters allow the model to account for conduction, convection, and radiation effects without requiring detailed analysis of each physical interface, maintaining computational efficiency while improving accuracy over simplified models that neglect exterior heat exchanges.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If heat exchanges with the exterior are neglected in the modeling, then calculation means are reduced, but the results remain unsatisfactory

Engineering Contradiction:
Improvecalculation efficiencyVSAvoidmodel reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary characterization of the building's thermal properties by measuring or calculating U-values for envelope elements, solar heat gain coefficients for glazing, and infiltration rates during periods when the building is unoccupied or at steady state. This preliminary action captures the dominant thermal parameters that govern exterior heat exchanges, allowing the model to reliably predict energy consumption while maintaining calculation efficiency through reduced-order thermal equations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent enables the thermal model to self-calibrate by using measured temperature and energy consumption data to automatically adjust thermal parameters (such as overall heat transfer coefficients and solar gain factors) without requiring manual intervention or complex optimization algorithms. This self-service capability improves model reliability while keeping the calculation framework simple and efficient.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach provides accurate energy consumption forecasting by considering key thermal phenomena, achieving better thermal regulation and precision in building energy management.

Implementation Method 1

the heating and cooling of the building by a heating and/or air conditioning device, passive solar contributions

Methodology Applied
Scientific EffectSolar radiation: Radiation

Implementation Method 2

heat exchanges of received solar radiation and/or convection and/or thermal conduction between the building and the external environment

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

heat exchanges of received solar radiation and/or convection and/or thermal conduction between the building and the external environment

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

a learning step to deduce therefrom the value of the parameters of the physical model from measurements made at the building level in the past

Methodology Applied
Scientific EffectLearning process:

Data Source

PatentEP2707781B1Method of predicting the energy consumption of a building
Publication Date: 2016.02.03 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP2707781B1 patent drawingFigure 1
  • EP2707781B1 patent drawing
  • EP2707781B1 patent drawing

AI summary

Method of predicting the energy consumption of a building, characterized in that it comprises a step of noting the thermal exchanges of solar radiation received and/or of convection and/or of thermal conduction between the building and the exterior environment on the basis of a physical model implemented by a computer, and in that it comprises a step of learning so as to deduce therefrom the value of the parameters of the physical model on the basis of measurements performed at the level of the building in the past.