Outlet Duct Heating in Window Ventilation to Prevent Freezing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Ventilation devices installed in windows face challenges with condensation water management and freezing issues, particularly at sub-zero temperatures, which affect their operating reliability and safety.

Innovation Solution

A ventilation device with a heat exchanger and an outlet duct containing a heating resistor, where a metal sleeve is used to maintain the mouth of the outlet duct unfrozen by collecting heat from the resistor, preventing freezing and icicle formation, and ensuring reliable operation by dissipating heating power effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a heating resistor is installed in the outlet duct to prevent freezing, then the operating reliability is improved, but the device complexity increases

Engineering Contradiction:
Improveoperating reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The heating resistor is nested inside the outlet duct, with the resistor positioned within the duct's internal space. This nested arrangement allows the heating function to be integrated into the existing outlet duct structure without requiring separate external heating components, thereby improving reliability while minimizing the increase in device complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The outlet duct itself acts as an intermediary medium that transfers heat from the heating resistor to the surrounding environment. The duct material conducts the generated heat to prevent freezing of the outlet, serving as a thermal mediator between the heating element and the external conditions

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the heating power is increased to better prevent freezing at sub-zero temperatures, then the reliability is improved, but the energy consumption increases

Engineering Contradiction:
Improveoperating reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The heating function is applied locally at the outlet duct where freezing is most critical, rather than heating the entire ventilation device. The heating resistor is positioned specifically at the outlet end, providing concentrated thermal energy only where needed to prevent ice formation, thus improving reliability while minimizing overall energy consumption

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The heating resistor's power output can be adjusted based on ambient temperature conditions. At sub-zero temperatures, the resistor operates at higher power to prevent freezing, while at milder temperatures, the power consumption is reduced. This dynamic parameter adjustment optimizes the balance between reliability and energy usage

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 effectively prevents freezing and icicle formation, enhancing the operating reliability and safety of the ventilation device by maintaining the outlet duct unfrozen, even at low temperatures, thus ensuring continuous and safe operation.

Implementation Method 1

a heating resistor (552) that follows the shape of the outlet tube (551)... for the collection of heat from the heating resistor (552) in order to prevent the freezing of the mouth of the outlet tube (551)

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

At the outer end of the outlet duct (55) is a metal sleeve (553) which is in a mechanical contact with the heating resistor (552) for the collection of heat from the heating resistor (552)

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3214253B1Ventilation device for a window
Publication Date: 2019.07.10 SKAALA IFN OY
  • EP3214253B1 patent drawingFigure 1
  • EP3214253B1 patent drawingFigure 2
  • EP3214253B1 patent drawingFigure 3~4

AI summary

In order to prevent the freezing of the mouth of the outlet duct, a ventilation device (100) equipped with a heat exchanger is presented, which ventilation device (100) comprises an outlet duct forming a drain connection from the heat exchanger to the exterior (U), inside which outlet duct is a heating resistor (552) that follows the shape of the outlet duct. At the outer end of the outlet duct is a sleeve (553) which is in a mechanical contact with the heating resistor for the collection of heat from the heating resistor (552) in order to prevent the freezing of the mouth of the outlet duct.