Sealed Thermostat Wall Box for Accurate Temperature Sensing

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Solution Overview

Problem

Temperature control devices, such as thermostats, face inaccuracies in temperature measurement due to heat generated by display screens and ambient light variations, which affect their ability to properly control temperature and humidity levels in a space.

Innovation Solution

A temperature control system comprising a sealed electrical wall box and glands that prevent air from the wall cavity from entering, allowing for accurate temperature sensing by isolating the device from airflow and providing airtight seals for various cable diameters, while also using adaptive illumination to minimize heat impact on temperature readings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the temperature control device is mounted in a standard electrical wall box, then it can be easily installed and accessed, but air from the wall cavity can enter and cause inaccurate temperature measurements

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidwall box sealing structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The wall box is divided into sealed and unsealed portions, with the sealed portion containing the temperature sensor and display screen. This segmentation isolates the temperature measurement environment from wall cavity air while maintaining installation simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A sealed barrier (such as a sealed back plate or sealing membrane) is introduced as an intermediary between the wall box interior and the wall cavity. This barrier prevents air exchange while allowing cable passage through sealed penetrations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If the display screen operates at high intensity, then it provides good visibility, but it generates heat that interferes with temperature sensor readings

Engineering Contradiction:
Improvedisplay screen brightnessVSAvoidtemperature measurement accuracy
Core Design Contradiction:
Illumination intensityVSMeasurement precision

Solution Approach 1:

The display screen is physically separated from the temperature sensor by placing it in a different compartment or on the opposite side of the wall box. This spatial extraction eliminates the heat interference while maintaining high display intensity for visibility.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A thermal barrier or heat sink is introduced as an intermediary between the display screen and the temperature sensor. This intermediary absorbs or blocks heat from the display while allowing the sensor to measure ambient temperature accurately.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If cables of various diameters are passed through the wall box, then electrical connections are flexible, but air can leak through the cable openings

Engineering Contradiction:
Improvecable accommodation flexibilityVSAvoidairtight seal integrity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

A flexible sealing membrane or grommet is used at each cable penetration point. These flexible elements can deform to accommodate cables of various diameters while maintaining an airtight seal around each cable, preventing air leakage.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The sealing mechanism uses adjustable parameters such as compression force or membrane tension to adapt to different cable diameters. By changing the sealing parameter (e.g., compression amount), the system maintains an airtight seal regardless of cable size.

Inventive Principle:
Principle #35Parameter changes

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

The solution ensures accurate temperature and humidity control by isolating the temperature control device from airflow and minimizing heat-generated inaccuracies, leading to improved measurement and control precision.

Implementation Method 1

The sealed electrical wall box may be configured to prevent air within a wall cavity of the wall from entering the sealed electrical wall box

Methodology Applied
Scientific EffectAir seal:

Implementation Method 2

The temperature control device may include a temperature sensor

Methodology Applied
Scientific EffectTemperature sensing:

Data Source

PatentEP3692616B1Temperature control device mounted to a sealed electrical wall box
Publication Date: 2023.08.02 LUTRON TECHNOLOGY COMPANY LLC
  • EP3692616B1 patent drawingFigure 1
  • EP3692616B1 patent drawingFigure 2
  • EP3692616B1 patent drawingFigure 3

AI summary

A temperature control system may include a temperature control device, an electrical wall box having a hole for passing a wire or cable into the wall box, and a gland configured to be inserted into the hole of the wall box. The temperature control device may include a temperature sensor. The wall box may be configured to be mounted to a wall. The temperature control device may be configured to be mounted to the wall box such that the temperature sensor is located within the wall box. A wire or cable may be passed from a wall cavity of the wall, through the gland once inserted into the hole of the wall box, into an interior of the wall box, and attached to the temperature control device. The gland and the wall box may be configured to prevent air within the wall cavity from entering the wall box when the wire or cable is passed into the wall box.