Occupancy-Sensing Thermostat Control for Automatic Setback

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing HVAC systems face challenges in accurately detecting periods of non-occupancy, leading to inefficient energy usage and increased costs, as programmable thermostats often fail to reflect users' actual behavior and require manual adjustments.

Innovation Solution

A method that uses occupancy sensors to automatically adjust the setpoint temperature based on detected occupancy patterns, implementing an 'auto away' and 'auto arrival' algorithm to change the temperature settings during predetermined intervals of non-occupancy, thereby reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If programmable thermostats are used with default schedules, then energy management capability is improved, but ease of operation deteriorates due to difficulty in programming and adjusting schedules to match actual occupancy patterns

Engineering Contradiction:

Improveenergy management capabilityVSAvoidease of programming

Core Design Contradiction:

Use of energy by moving objectVSEase of operation

Solution Approach 1:

The thermostat system performs self-service by automatically detecting occupancy patterns through sensors and autonomously adjusting temperature schedules without requiring user programming. The system learns and adapts to actual occupancy behavior, eliminating the need for manual schedule configuration while maintaining energy management capabilities.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system implements feedback mechanisms by continuously monitoring occupancy sensor data and using this information to dynamically adjust temperature setpoints. The thermostat receives feedback about actual occupancy patterns and modifies its operation accordingly, creating a closed-loop control system that improves energy management without requiring user intervention.

Inventive Principle:

Principle #23Feedback

2Loss of energy

If manual thermostat adjustment is required to match occupancy patterns, then energy efficiency is improved, but productivity deteriorates due to time spent on manual adjustments

Engineering Contradiction:

Improveenergy efficiencyVSAvoidtime spent on adjustments

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The thermostat system autonomously monitors occupancy through integrated sensors and automatically adjusts temperature settings to match detected occupancy patterns, eliminating the need for manual intervention. This self-service capability maintains energy efficiency while freeing users from the time-consuming task of manual thermostat adjustments.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system replaces manual mechanical thermostat adjustment with automated electronic control based on sensor data. Occupancy sensors detect presence and absence, and the control system automatically modifies temperature setpoints, substituting the manual mechanical adjustment process with an automated electronic system that improves both energy efficiency and user productivity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of energy

If occupancy detection is implemented to automatically adjust temperatures, then energy savings are improved, but device complexity increases due to additional sensors and algorithms

Engineering Contradiction:

Improveenergy savingsVSAvoidcomplexity of sensors and algorithms

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent combines occupancy detection sensors, temperature sensing, and control algorithms into an integrated thermostat system. By merging these previously separate functions into a single unified device, the system achieves automatic occupancy-based temperature adjustment and energy savings while minimizing the increase in overall device complexity through functional integration.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The thermostat system is designed with multi-functionality, serving as both a temperature control device and an occupancy detection system. The single device performs multiple functions including environmental sensing, occupancy detection, schedule management, and automatic control, reducing the need for separate dedicated devices and thereby limiting the increase in complexity while maximizing energy savings capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS8950686B2Control unit with automatic setback capability

Publication Date: 2015.02.10 GOOGLE LLC

AI summary

Methods for controlling temperature in a conditioned enclosure such as a dwelling are described that include an “auto-away” and/or “auto-arrival” feature for detecting unexpected absences which provide opportunities for significant energy savings through automatic adjustment of the setpoint temperature. According to some preferred embodiments, when no occupancy has been detected for a minimum time interval, an “auto-away” feature triggers a changes of the state of the enclosure, and the actual operating setpoint temperature is changed to a predetermined energy-saving away-state temperature, regardless of the setpoint temperature indicated by the normal thermostat schedule. The purpose of the “auto away” feature is to avoid unnecessary heating or cooling when there are no occupants present to actually experience or enjoy the comfort settings of the schedule, thereby saving energy.