Personal Breathing Zone Laminar Airflow Using Temperature Gradient
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Solution Overview
Problem
Existing devices that provide a purified personal breathing zone during sleep often suffer from uncomfortable air flow drafts, dehydration, and poor control over filtered air stream velocity due to turbulent mixing of ambient air, which is not effectively addressed by current HEPA filtration systems.
Innovation Solution
The use of Temperature Controlled Laminar Airflow (TLA) technology, which induces a substantially laminar flow of filtered air by creating a temperature gradient between the supply air and ambient air, ensuring a descending air flow with a controlled velocity that displaces body convection currents without excessive drafts, using a single filtered air stream adjusted via a thermoelectric cooler to maintain an optimal temperature difference of 0.3 to 1°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If impulse or forced-blown air is used to provide a purified personal breathing zone, then filtered air can be delivered to the breathing zone, but uncomfortable air flow drafts and turbulent in-mixing of contaminated ambient air occur
Solution Approach 1:
The invention changes the velocity parameter of the filtered air stream by utilizing gravitational force instead of impulse or blowing force. The cooled filtered air, being denser than ambient air, descends slowly at a controlled velocity that avoids turbulent mixing and uncomfortable drafts while still effectively displacing body convection currents.
Solution Approach 2:
The invention replaces the mechanical blowing system with a gravity-based system. Instead of using fans or blowers to force air movement, the system relies on the density difference between cooled filtered air and warmer ambient air to create a natural downward flow that is both comfortable and controllable.
2Productivity
If high velocity forced-blown air is used to displace body convection, then body convection currents can be disrupted, but turbulent in-mixing of contaminated ambient air occurs
Solution Approach 1:
The invention changes the velocity parameter to a lower, gravity-determined value that maintains laminar flow stability. The cooled filtered air descends slowly enough to remain laminar while still being sufficiently fast to displace body convection currents and remove contaminants effectively.
Solution Approach 2:
The invention creates a localized controlled environment at the breathing zone where laminar flow conditions are maintained. The cooled air stream is directed specifically at the breathing zone to disrupt body convection currents without causing turbulent mixing with ambient air in the surrounding area.
3Speed
If temperature difference between supply air and ambient air is increased to control air flow velocity, then air flow velocity can be controlled, but excessive temperature difference causes uncomfortable drafts
Solution Approach 1:
The invention uses feedback control to maintain the temperature difference within the optimal range of 0.3 to 1°C. Temperature sensors monitor the supply air and ambient air temperatures, and the system adjusts cooling to keep the temperature difference within this range, ensuring both adequate air stream velocity and user comfort.
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 approach provides a comfortable and effective personal breathing zone by minimizing turbulent mixing, reducing noise, and maintaining a stable air-temperature difference to ensure the filtered air stream's velocity is sufficient to displace body convection currents without causing drafts, thus enhancing user compliance and air quality.
Implementation Method 1
induces a substantially laminar flow of filtered air by creating a temperature gradient between the supply air and ambient air
Implementation Method 2
A substantially laminar flow of filtered, colder air, having a higher density than ambient air descends slowly
Implementation Method 3
Stable flow conditions are maintained by introducing a temperature gradient (negative buoyancy) between the cooled supply air and ambient air
Implementation Method 4
Temperature control is facilitated by a thermoelectric cooler (TEC) using the Peltier effect with reversible polarity
Data Source
AI summary
Methods and devices are provided whereby a controlled personal breathing zone is maintained using temperature controlled laminar air flow (TLA) of filtered air. A substantially laminar, descending flow of filtered air is maintained with a velocity determined by the air-temperature difference between the supplied air and the ambient air t at the level of the personal breathing zone. The air-temperature of the filtered supply air can be carefully adjusted to maintain the velocity-determining difference in air-temperature within the optimum range of 0.3 to 1° C. Thus being able to at the same time displace body convection and achieve comfort.