Ceiling Air Conditioner Drain Pan Layout for Antimicrobial Drain Water

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Solution Overview

Problem

In ceiling-mounted air conditioner indoor units, expanding the drain pan to accommodate an antimicrobial agent reduces the cross-sectional area of the outlet passage, leading to increased noise and fan power consumption, particularly in compact designs where space is limited for components like the drain pump, float switch, and antimicrobial agent.

Innovation Solution

The antimicrobial agent is installed directly below the heat exchanger on the drain pan, with part of the antimicrobial unit positioned in an opening groove of the partition wall, allowing the drain water to pass through while maintaining the original cross-sectional area of the outlet passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the drain pan is expanded to accommodate the antimicrobial agent near the drain pump, then the antimicrobial effect is improved, but the cross-sectional area of the outlet passage is reduced

Engineering Contradiction:
Improveantimicrobial effectVSAvoidcross-sectional area of outlet passage
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The antimicrobial unit is relocated from the conventional position near the drain pump to a position directly below the heat exchanger, utilizing the vertical space and different spatial dimension. This dimensional change allows the antimicrobial agent to remain effective while preserving the outlet passage cross-sectional area, as the new position does not encroach on the airflow path.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the drain pan is expanded to provide space for the antimicrobial agent, then the antimicrobial function is improved, but noise increases due to reduced outlet passage area

Engineering Contradiction:
Improvesterilization functionVSAvoidnoise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

By positioning the antimicrobial unit below the heat exchanger rather than expanding the drain pan laterally, the invention utilizes the vertical dimension to accommodate the sterilization function. This prevents encroachment on the outlet passage area, thereby maintaining airflow efficiency and preventing noise increase.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If the drain pan is expanded to accommodate the antimicrobial agent, then the antimicrobial effect is improved, but fan power consumption increases

Engineering Contradiction:
Improvedrain water sterilizationVSAvoidfan power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The antimicrobial unit is installed in the space directly below the heat exchanger, utilizing the vertical arrangement rather than lateral expansion. This dimensional repositioning maintains the outlet passage cross-sectional area, ensuring that airflow resistance remains unchanged and fan power consumption does not increase.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Reliability

If the drain pan is expanded to provide space for components, then the antimicrobial agent can be arranged, but the ratio of space occupied by components increases in compact designs

Engineering Contradiction:
Improveantimicrobial functionVSAvoidspace occupation ratio
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

In compact indoor units, the invention utilizes the vertical space below the heat exchanger to install the antimicrobial unit, rather than expanding the drain pan laterally. This dimensional change allows effective use of available space, maintaining a low component space occupation ratio while still providing the necessary antimicrobial function.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

This configuration prevents a reduction in the cross-sectional area of the outlet passage, maintaining airflow efficiency and reducing noise and fan power consumption, while ensuring effective sterilization of drain water.

Implementation Method 1

an antimicrobial unit that is installed on the drain pan and has an antimicrobial agent to sterilize drain water

Methodology Applied
Scientific EffectAntimicrobial sterilization:

Implementation Method 2

cools the sucked air with a heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

sucks indoor air by rotating a centrifugal fan

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3321602B1Indoor unit for air conditioner
Publication Date: 2021.05.26 HITACHI JOHNSON CONTROLS AIR CONDITIONING INC
  • EP3321602B1 patent drawingFigure 1
  • EP3321602B1 patent drawingFigure 2~4
  • EP3321602B1 patent drawingFigure 5~7

AI summary

An indoor unit for an air conditioner includes: a blower fan that is arranged in a casing; a heat exchanger that encompasses all air flow directions from the blower fan; a drain pan that is arranged below the heat exchanger; and an antimicrobial unit that is installed on the drain pan and has an antimicrobial agent to sterilize drain water. At least a part of the antimicrobial unit is arranged directly below the heat exchanger. The indoor unit has the antimicrobial agent arranged on the drain pan while a cross-sectional area of an outlet passage is prevented from being reduced.