Ceiling Air Conditioning Unit Fan Positioning to Reduce Noise
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Solution Overview
Problem
Existing ceiling air conditioning units generate unsatisfactory noise levels, affecting occupants in vehicles or rooms due to direct airflow paths and obstructed fan outputs.
Innovation Solution
The fan is positioned such that at least 30% of its output area is above the evaporative unit, with indirect airflow paths to the evaporative unit, and the use of a plenum to reduce noise, along with deep, multi-row coils and a smaller diameter centrifugal fan to enhance airflow efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the fan is positioned at the same level as the evaporative unit with direct airflow, then the device complexity is reduced, but the noise level increases and airflow efficiency decreases
Solution Approach 1:
The fan is positioned vertically above the evaporative unit rather than at the same level, creating a vertical airflow path that passes through the evaporative coils. This dimensional change allows the airflow to be directed downward through the evaporator, improving heat exchange efficiency while reducing noise by at least 5dB(A) compared to horizontal direct airflow configurations
2Loss of time
If the fan air output is directly directed through the evaporative unit, then the airflow path is shortened, but the noise level increases and condensate generation increases
Solution Approach 1:
The airflow path is configured to curve downward through the evaporative unit rather than flowing directly through, creating a smoother flow path that reduces turbulence. This curved path allows air to enter the evaporator from above, pass through the coils, and exit downward, reducing turbulent noise and minimizing condensate formation by avoiding abrupt flow direction changes
3Object-affected harmful factors
If a wall is placed between the fan air output and evaporative unit for indirect airflow, then noise is reduced, but the device complexity and airflow resistance increase
Solution Approach 1:
The fan is extracted from the traditional horizontal positioning and relocated to a vertical position above the evaporative unit. This extraction eliminates the need for intermediate walls or complex ducting structures, as the vertical positioning itself creates the indirect airflow path. The fan blows air downward through the evaporator, achieving noise reduction without requiring additional structural elements
4Productivity
If the fan diameter is increased to enhance airflow volume, then the airflow volume increases, but the noise level and space requirements increase
Solution Approach 1:
The fan operating parameters are optimized by positioning it vertically above the evaporative unit with its air output directed downward. This parameter change in positioning and airflow direction allows the fan to operate more efficiently at potentially smaller diameters while maintaining high airflow volume. The vertical configuration improves airflow velocity through the evaporator, achieving high productivity without the noise and space penalties of larger diameter fans
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 reduces noise by at least 5dB(A) while maintaining high airflow volume and improving sensible heat ratio, providing enhanced occupant comfort and reduced condensate generation.
Implementation Method 1
an evaporative unit, in the conditioning chamber; wherein the fan draws in entry air to enter the air conditioning unit, then through the evaporative unit, to condition the entry air to produce conditioned air
Data Source
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AI summary
An air conditioning unit, comprising: a conditioning chamber; a fan, in the conditioning chamber, with a fan air input and a fan air output; and an evaporative unit, in the conditioning chamber; wherein the fan draws in entry air to enter the air conditioning unit, then through the evaporative unit, to condition the entry air to produce conditioned air; and wherein, within the conditioning chamber, the fan is positioned and configured such that at least 30% of an area of the fan air output are positioned above an average top surface of the evaporative unit, and that air from the at least 30% of the area of the fan air output is directed towards a wall of the conditioning chamber prior to being redirected downwards and through the evaporative unit.