Residential Ventilation Fan Inlet Grid for Lower Noise and Power
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Solution Overview
Problem
Existing ventilation devices for residential buildings are inefficient in terms of electrical power usage, generate significant noise, and suffer from high flow drops and turbulence, leading to increased pressure drops and noise emissions.
Innovation Solution
The use of a permanently excited electronically commutated synchronous motor with a single flow, free-running diagonal or radial fan impeller and a grid structure flow conditioner minimizes input power, reduces noise, and simplifies the fan design, while the grid structure homogenizes air inflow and reduces turbulence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If an asynchronous internal rotor motor with forward curved radial impeller is used, then the fan can overcome pressure drops in the duct system, but the electrical input capacity is high and efficiency is low
Solution Approach 1:
The patent changes the motor type from asynchronous to permanently excited electronically commutated synchronous motor, and changes the impeller design from forward curved to backward curved blades. These parameter changes result in significantly reduced electrical input capacity while maintaining the same air flow capacity and pressure drop overcoming ability.
2Power
If forward curved radial impellers are used, then the fan can generate sufficient pressure, but the degree of efficiency is relatively low and noise emission is significant
Solution Approach 1:
The patent inverts the conventional forward curved blade design by using backward curved blades. This inversion of the blade curvature direction results in improved efficiency and reduced noise emission while maintaining the pressure generation capability needed to overcome duct system resistance.
3Productivity
If a fully closed duct system is used, then air can be directed from inlet to outlet, but turbulence and low-frequency noise especially blade passing noise increase
Solution Approach 1:
The patent changes the blade curvature parameter from forward to backward, which modifies the airflow pattern within the closed duct. This parameter change reduces turbulence intensity and minimizes low-frequency blade passing noise while preserving the air flow capacity required for ventilation productivity.
4Productivity
If conventional fans with forward curved blades are used, then air can be moved through the system, but the complexity of the complete fan is high and weight of components is significant
Solution Approach 1:
The patent extracts the housing enclosure from around the fan impeller, creating a free running fan design. This extraction simplifies the overall fan structure, reduces component weight, and maintains air movement capability by allowing the impeller to operate freely without the enclosing housing.
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 results in reduced electrical power consumption, lower noise emissions, and minimized pressure drops, maintaining air flow capacity while simplifying the fan design and reducing weight.
Implementation Method 1
a permanently excited electronically commutated synchronous motor
Implementation Method 2
a fan impeller arranged in the housing, with a fan impeller driven by an electric motor
Implementation Method 3
the grid structure according to the present invention homogenizes the inflow by reducing turbulence
Data Source
AI summary
A ventilation device, in particular for heating, cooling and/or humidifying air in residential buildings, includes a duct-shaped housing (1) with an air inlet opening (2) and an air outlet opening (3), and a fan impeller (6) as well as a filter unit, heat exchange unit and/or heating coil unit (14) arranged in the main flow direction (Z) of an air flow generated by the fan impeller (6). An air guiding device (17) is arranged in the flow direction (Z) of the air flow in front of a suction nozzle (16)—configured as a flow conditioner, includes a bar structure with air guiding bars-such that a flow inlet opening is configured on the suction side at an axial height in front of the flow inlet opening (15) by the bar structure whose opening surface is smaller than the opening surface of the flow inlet opening (15).