Displacement ventilation systems for enclosed spaces
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Solution Overview
Problem
Conventional mixed ventilation systems in buildings often result in poor air quality, excessive noise, and lower comfort levels, particularly in school environments, leading to adverse health effects and reduced performance among occupants.
Innovation Solution
A displacement ventilation system that delivers fresh air near the floor, utilizing a vertical airflow pattern to carry contaminants towards the ceiling for removal, incorporating a heat exchanger and heat pump for energy efficiency, and a diffuser with a porous diffusion plate to minimize noise and enhance air distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If mixed ventilation systems are used, then air circulation is achieved, but air quality deteriorates and noise increases
Solution Approach 1:
The patent inverts the conventional mixed ventilation approach by using displacement ventilation, where supply air is delivered at low velocity near the floor and allowed to rise naturally through thermal buoyancy, rather than forcing high-velocity air throughout the space. This inversion of the ventilation strategy eliminates the need for high-velocity air movement, thereby reducing noise while improving air quality through vertical air flow patterns that prevent horizontal germ spread.
Solution Approach 2:
The patent replaces the mechanical forced-air circulation system with a natural convection-based system. Instead of relying on mechanical means to circulate air throughout the space, the system utilizes natural thermal buoyancy forces to drive air movement, allowing warm air to rise and create circulation patterns without mechanical assistance, thereby reducing noise and improving air quality.
2Productivity
If high velocity air flow is used for ventilation, then air circulation is improved, but noise increases
Solution Approach 1:
The patent inverts the conventional approach by using low-velocity supply air that rises naturally through thermal buoyancy rather than forcing high-velocity air circulation. This inversion maintains effective air circulation through natural convection currents while eliminating the noise associated with high-velocity air movement.
Solution Approach 2:
The patent changes the velocity parameter of supply air from high to low, and utilizes temperature differences to drive air movement. By delivering air at low velocity and allowing thermal buoyancy to accelerate the air upward, the system achieves effective circulation without the noise penalties of high-velocity systems.
3Object-affected harmful factors
If displacement ventilation is implemented, then air quality and comfort improve, but system complexity increases
Solution Approach 1:
The displacement ventilation system is designed to be self-regulating, utilizing natural thermal buoyancy forces to drive air circulation without requiring complex mechanical controls or variable speed drives. The system leverages the natural tendency of warm air to rise and cool air to sink, creating self-sustaining circulation patterns that improve air quality while maintaining system simplicity.
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 system improves indoor air quality, reduces noise, minimizes energy use, and increases occupant comfort, leading to better health outcomes, lower absentee rates, and enhanced productivity while meeting acoustic standards.
Implementation Method 1
a heat exchanger located between the air inlet and the return air duct for transferring thermal energy between the return air and the outside air
Implementation Method 2
a heat pump located between the air inlet and the elongated diffuser for changing the temperature level of the outside air and/or the return air passing through the heat pump
Implementation Method 3
an elongated diffuser extending adjacent the floor of the enclosed space and being coupled with the vertical duct for diffusing at least some of the outside air over the floor of the enclosed space
Implementation Method 4
the quality of the air located within an enclosed space supplied by the displacement ventilation systems disclosed herein may be improved due to rising thermal plumes that carry contaminants and pollutants away from occupants and toward a ceiling exhaust
Data Source
AI summary
A displacement ventilation system includes a vertical duct located inside an enclosed space and extending between a floor and a ceiling of the enclosed space, an air inlet coupled with the vertical duct for drawing air into the displacement ventilation system, and an elongated diffuser extending adjacent the floor for diffusing at least some of the outside air over the floor of the enclosed spaced. The displacement ventilation system desirably includes a return air duct extending adjacent the ceiling and being coupled with the vertical duct for removing return air from the enclosed space and advancing the return air toward the vertical duct, a heat exchanger for transferring thermal energy between the return air and the outside air, and a heat pump for changing a temperature level of the outside air or the return air passing through the heat pump.