Heat-Exchange Ventilation Drain Pan Layout to Prevent Air Mixing

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Solution Overview

Problem

Conventional heat-exchange type ventilation apparatuses face issues with air mixing between supply airflow, discharge airflow, and air under the roof due to separate drain pans on the discharge and supply air sides, leading to inefficient ventilation and potential condensation problems.

Innovation Solution

A heat-exchange type ventilation apparatus with a unified drain pan that integrates supply-air-side and discharge-air-side drain pan portions, covering the entire bottom surface and featuring a groove to prevent air mixing, along with air supplying and discharging fans to manage airflow effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate drain pans are provided on the discharge air side and supply air side, then drain water can be retained in each path, but air under the roof enters through the joint between drain pans and supply/discharge airflow mixes with air under the roof

Engineering Contradiction:
Improvedrain water retentionVSAvoidair mixing
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent merges the separate drain pans into a single integrated drain pan structure that covers the entire bottom surface of the housing. This unified structure eliminates the joint between separate drain pans where air leakage occurred, while still providing separate retention areas for supply air path drain water and discharge air path drain water through internal partitioning.

Inventive Principle:
Principle #5Merging (Combining)

2Object-generated harmful factors

If an integrated drain pan is provided covering the entire bottom surface, then air mixing is prevented, but the structure becomes more complex

Engineering Contradiction:
Improveair mixing preventionVSAvoiddrain pan structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The integrated drain pan is segmented into distinct regions: a supply air path drain water retention area and a discharge air path drain water retention area, separated by a partition wall. This segmentation allows the single structure to perform multiple functions (preventing air mixing while retaining drain water from both paths separately) without requiring multiple separate components.

Inventive Principle:
Principle #1Segmentation

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 mixing of supply or discharge airflow with air under the roof, enhancing ventilation efficiency and reducing condensation-related issues by integrating drain pans and optimizing fan placement within the apparatus.

Implementation Method 1

a heat exchanger (2) placed in the main body (1) to allow heat exchange between a supply airflow passing through the supply air path and a discharge airflow passing through the discharge air path

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

an air supplying fan to generate the supply airflow, the air supplying fan being fixed inside the main body

Methodology Applied
Scientific EffectFan-driven airflow: Fan

Implementation Method 3

an air discharging fan to generate the discharge airflow, the air discharging fan being fixed inside the main body

Methodology Applied
Scientific EffectFan-driven airflow: Fan

Implementation Method 4

the drain pan has a groove that faces a rib that surrounds a motor accommodating portion of the air supplying fan

Methodology Applied
Scientific EffectGravity-driven liquid retention: Gravitation

Data Source

PatentEP3258181B1Heat exchange-type ventilation device
Publication Date: 2020.12.16 MITSUBISHI ELECTRIC CORP
  • EP3258181B1 patent drawingFigure 1
  • EP3258181B1 patent drawingFigure 2
  • EP3258181B1 patent drawingFigure 3

AI summary

A heat-exchange type ventilation apparatus (100) includes: a main body (1) in which a supply air path to supply outside air to an inside of a room and a discharge air path to discharge inside air to an outside of the room are formed; a heat exchanger (2) placed in the main body (1) to allow heat exchange between a supply airflow passing through the supply air path and a discharge airflow passing through the discharge air path; an air supplying fan (3) to generate the supply airflow, the air supplying fan being fixed inside the main body (1); an air discharging fan (4) to generate the discharge airflow, the air discharging fan being fixed inside the main body (1); and a drain pan (11) including a supply-air-side drain pan portion and a discharge-air side drain pan portion that are integrally formed with each other and covering an entire bottom surface of the main body (1), the supply-air-side drain pan portion retaining drain water generated in the supply air path inside the heat exchanger (2), the discharge-air side drain pan portion retaining drain water generated in the discharge air path inside the heat exchanger.