Method and system for heating auto-setback

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Solution Overview

Problem

Conventional HVAC systems lack the ability to autonomously determine optimal operating parameters when a space is unoccupied, leading to unnecessary energy expenditure as they rely on user-input set-point temperatures without considering energy minimization.

Innovation Solution

An HVAC system equipped with a controller that predicts temperatures during unoccupied times and adjusts runtime operations to ensure the space reaches the set-point temperature only when necessary, using a combination of heat pumps and heating elements efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the HVAC system operates continuously to maintain set-point temperature, then the temperature comfort is ensured, but energy consumption increases

Engineering Contradiction:
Improveset-point temperatureVSAvoidHVAC energy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary heating during unoccupied periods by predicting the temperature trajectory and determining the optimal runtime needed to reach the set-point temperature before occupancy begins. This advance action ensures comfort is achieved efficiently without requiring continuous operation throughout the entire period.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the HVAC runtime based on real-time predictions of temperature changes, occupancy status, and environmental conditions. Rather than using fixed schedules or continuous operation, the runtime is optimized dynamically to match actual needs, reducing energy consumption while maintaining temperature comfort.

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If the HVAC system uses predictive algorithms to optimize runtime, then energy consumption is reduced, but system complexity increases

Engineering Contradiction:
ImproveHVAC energy consumptionVSAvoidcontroller complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The controller autonomously performs temperature predictions, occupancy detection, and runtime optimization without requiring complex external systems or manual intervention. The system serves itself by automatically adjusting operations based on predicted conditions, reducing the need for additional complex control infrastructure.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system incorporates feedback mechanisms where the controller continuously monitors actual temperature, occupancy status, and environmental conditions, then adjusts predictive models and runtime decisions accordingly. This feedback loop enables accurate optimization without requiring overly complex predetermined algorithms.

Inventive Principle:
Principle #23Feedback

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 reduces energy consumption by optimizing HVAC runtime and energy usage, as illustrated by charts showing lower furnace power consumption compared to user-controlled systems.

Implementation Method 1

predict a first predicted temperature of an enclosed space during an unoccupied time with the HVAC system off

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

predict a second predicted temperature of the enclosed space if the HVAC system is operated for a first runtime

Methodology Applied
Scientific EffectHeat transfer: Convection

Implementation Method 3

a condenser coil coupled between the evaporator coil and the compressor

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 4

using a combination of heat pumps and heating elements efficiently

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Data Source

PatentEP3587935B1Method and system for heating auto-setback
Publication Date: 2021.04.21 LENNOX IND INC
  • EP3587935B1 patent drawingFigure 1
  • EP3587935B1 patent drawingFigure 2
  • EP3587935B1 patent drawingFigure 3A

AI summary

A method of operating an HVAC system using a controller includes predicting a first predicted temperature of an enclosed space during an unoccupied time with the HVAC system off. The controller determines if the first predicted temperature is less than a set-point temperature. Responsive to a determination that the first predicted temperature is less than the set-point temperature, the controller predicts a second predicted temperature of the enclosed space if the HVAC system is operated for a first runtime. The controller determines if the second predicted temperature is less than the set-point temperature and, responsive to a determination that the second predicted temperature is not less than the set-point temperature, the controller operates the HVAC system for the first runtime.