Refrigerated Display Door Airflow Layout for Condensation Control

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Solution Overview

Problem

Refrigerated sales furniture with glass doors experiences condensation issues on the lower portions due to temperature drops below the dew point, leading to undesirable condensate formation, which affects energy efficiency and thermal insulation.

Innovation Solution

A warm air channel system is integrated into the refrigerated sales furniture, utilizing a deflection element to direct ambient warm air into the refrigerated space, merging it with cold air flows to maintain the temperature above the dew point at the door's lower portion, without additional fans or electrical components, by leveraging the existing cold air flow induced by fans.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If glass doors are used to establish separation between refrigerated space and warm environment, then energy efficiency is enhanced, but condensation forms on the lower portion of the doors

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcondensation formation
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing thermal insulation specifically at the lower portion of the door where condensation occurs, rather than insulating the entire door. The insulating element is positioned locally at the bottom edge of the glass door to raise the surface temperature above the dew point, preventing condensation while maintaining the glass door's transparency and insulation properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces an insulating element as an intermediary component between the cold refrigerated space and the warm external environment at the door's lower portion. This intermediary element acts as a thermal buffer, reducing heat transfer through the door edge and preventing the glass surface from reaching the dew point temperature.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the lower portion of the door is insulated to prevent condensation, then condensation is avoided, but the door design requires modification

Engineering Contradiction:
Improvecondensation preventionVSAvoiddoor design complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent segments the door structure by separating the glass door panel from its frame and adding a distinct insulating element at the lower portion. This segmentation allows the insulating component to be added independently without redesigning the entire door assembly, maintaining simplicity while addressing condensation issues.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the insulation function from the main door structure by providing a separate, removable insulating element that can be attached to the lower portion of the door. This extraction allows the door to maintain its original design while adding insulation functionality where needed, minimizing design complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Temperature

If thermal insulation is provided at the lower door portion, then temperature is maintained above dew point, but the structure becomes more complex

Engineering Contradiction:
Improvedoor surface temperatureVSAvoidstructural complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent applies local quality by providing thermal insulation specifically at the lower portion of the door where condensation occurs, rather than insulating the entire door. The insulating element is positioned locally at the bottom edge of the glass door to raise the surface temperature above the dew point, preventing condensation while maintaining the glass door's transparency and insulation properties.

Inventive Principle:
Principle #3Local quality

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

Effectively prevents condensate formation on the door's lower portion by increasing convective heat transfer and maintaining the temperature above the dew point, enhancing energy efficiency and thermal insulation without modifying the door design or adding active components.

Implementation Method 1

A warm air channel (18) extending from an exterior into a lower portion of the refrigerated sales space (28) is provided. The warm air channel (18) is configured to guide a flow of warm air from an area in front of the refrigerated sales furniture (10) into the refrigerated sales space (28) in order to establish a positive temperature differential at a lower portion of the at least one door (8) with respect to the dew point temperature of the ambient air (A).

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

The refrigerated sales furniture (10) is configured such that the flow of cold air (C) sucks a flow of warm air (W) through the at least one warm air channel (18) and merges with the flow of cold air (C).

Methodology Applied
Scientific EffectBernoulli effect: Bernoulli Effect

Implementation Method 3

A flow of cold air (C) is provided flowing substantially vertically in a downward direction in at least a lower front portion of the refrigerated sales space (28) next to an inside of a lower portion of the at least one door (8).

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP3393307B1Refrigerated sales furniture
Publication Date: 2020.01.01 CARRIER CORP
  • EP3393307B1 patent drawingFigure 1
  • EP3393307B1 patent drawingFigure 2
  • EP3393307B1 patent drawingFigure 3

AI summary

A refrigerated sales furniture (10) is configured for providing a flow of cold air (C) flowing substantially vertically in a downward direction in at least a lower front portion of a refrigerated sales space (28) and along the inside of a lower portion of at least one door (8). The refrigerated sales furniture (10) comprises at least one warm air channel (18) extending below the at least one door (8) from a front side of the refrigerated sales furniture (10) into the refrigerated sales furniture (10). A deflection element (20; 21 ) is fixed to an inner surface of the at least one door (8) for deflecting the flow of cold air (C) and generating a local low pressure. The warm air channel (18) is configured for flowing warm air from an area in front of the refrigerated sales furniture (10) into the refrigerated sales furniture (10) and for keeping the temperature at a lower portion of the at least one door (8) above the dew point temperature of the ambient air (A). The refrigerated sales furniture (10) is configured such that the flow of warm air (W) is sucked through the at least one warm air channel (18) by the flow of cold air (C) and merges with the flow of cold air (C).