Icemaker Temperature Control Using Dewpoint Feedback to Prevent Sweat

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Solution Overview

Problem

Refrigerator appliances face challenges in achieving high ice production rates without causing external sweat due to increased fan speeds or lowering freezer cabinet temperature, which can lead to noise and humidity issues.

Innovation Solution

A refrigerator appliance with a sealed system for temperature regulation, an ambient humidity sensor, and a controller that adjusts the chamber temperature based on dewpoint conditions to maintain an outer surface temperature above the dewpoint, allowing for increased ice production while preventing sweat formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If fan speed is increased to achieve higher air flow to the ice maker, then ice production rate is improved, but noise level increases

Engineering Contradiction:

Improveice production rateVSAvoidnoise

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system changes the temperature parameter of the freezer cabinet to a lower value temporarily during ice making cycles. This allows increased ice production without requiring higher fan speeds, thereby avoiding noise generation while maintaining productivity improvement

Inventive Principle:

Principle #35Parameter changes

2Productivity

If freezer cabinet temperature is lowered below normal operating temperature to increase ice rate, then ice production rate is improved, but external sweat occurs due to higher ambient humidity level

Engineering Contradiction:

Improveice production rateVSAvoidexternal sweat

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system uses a humidity sensor to monitor ambient humidity levels and provides feedback to the controller. Based on this feedback, the controller adjusts the chamber temperature dynamically - lowering it to increase ice production when humidity is low, and raising it when humidity is high to prevent external sweat formation

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the freezer cabinet temperature based on real-time humidity conditions rather than maintaining a fixed low temperature. This dynamic adjustment allows the system to optimize ice production while preventing external sweat by adapting to changing environmental conditions

Inventive Principle:

Principle #15Dynamics

3Productivity

If freezer cabinet temperature is lowered to increase ice making rate, then ice production rate is improved, but energy consumption increases

Engineering Contradiction:

Improveice production rateVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The system implements periodic ice making cycles with temporary temperature reductions rather than continuous low-temperature operation. The controller lowers the chamber temperature only during specific ice making cycles and restores it to normal operating temperature afterward, reducing overall energy consumption while maintaining improved ice production capability

Inventive Principle:

Principle #19Periodic action

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

Enhances ice production rates while minimizing the likelihood of external sweat on the refrigerator surface by optimizing temperature control based on ambient humidity levels.

Implementation Method 1

an ambient humidity sensor... obtain an ambient humidity using the ambient humidity sensor

Methodology Applied

Scientific EffectHumidity sensing: Hygrometer

Implementation Method 2

a sealed system for regulating a chamber temperature within the chilled chamber... operate the sealed system to regulate the chamber temperature to the target temperature

Methodology Applied

Scientific EffectTemperature regulation: Heat Exchanger

Implementation Method 3

determine, based on the ambient humidity, a dewpoint temperature where sweat will be produced on an outer surface of the refrigerator appliance

Methodology Applied

Scientific EffectDewpoint calculation:

Implementation Method 4

operate the icemaker to produce ice at an increased icemaking rate

Methodology Applied

Scientific EffectFreezing: Freezing

Data Source

PatentUS20250347456A1Method of operating an icemaker of a refrigerator appliance

Publication Date: 2025.11.13 HAIER US APPLIANCE SOLUTIONS INC

AI summary

A refrigerator appliance includes an icemaker mounted to a door within a chilled chamber, a sealed system for regulating a chamber temperature within the chilled chamber, an ambient humidity sensor, and a controller in operative communication with the icemaker, the sealed system, and the ambient humidity sensor. The controller is configured to obtain an ambient humidity using the ambient humidity sensor, determine, based on the ambient humidity, a dewpoint temperature where sweat will be produced on an outer surface of the refrigerator appliance, determine a target temperature that maintains an outer surface temperature to equal or greater than the dewpoint temperature, operate the sealed system to regulate the chamber temperature to the target temperature, and operate the icemaker to produce ice at an increased icemaking rate.