Suspended Ceiling Ventilation Using Induction Mixing to Prevent Drafts
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Solution Overview
Problem
Existing ventilation and temperature control systems for rooms with suspended ceilings often result in drafts and uneven temperature distribution due to inadequate mixing of primary and secondary air flows, leading to inefficient temperature control and increased energy consumption.
Innovation Solution
A method that directs a primary air flow through nozzle ducts in the ceiling cavity, using air induction to mix with secondary room air, which is sucked into the cavity through leaks in the ceiling, creating a low-turbulence, draught-free flow and enhancing the thermal exchange capacity of the ceiling for temperature control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooled fresh air is blown directly into the room through ceiling connections, then cooling effect is achieved, but drafts and temperature differences occur in the room
Solution Approach 1:
The ceiling cavity serves as an intermediary mixing chamber between the cooled primary air and the warmer room air. Primary air is blown into the ceiling cavity where it mixes with secondary air drawn from the room through the suspended ceiling, creating tempered air that is then supplied to the room without causing drafts or excessive temperature differences
Solution Approach 2:
The solution moves the air mixing process from the room space (three-dimensional turbulent mixing) to the ceiling cavity (two-dimensional laminar flow along the ceiling surface). This dimensional change allows for controlled, low-turbulence mixing that eliminates drafts while achieving temperature control
2Power
If primary air is introduced at low temperature for efficient cooling, then cooling capacity is improved, but temperature control power increases
Solution Approach 1:
The system changes the temperature parameter of the primary air from low temperature (which would require high cooling power) to a moderate temperature that is closer to the desired room temperature. This allows the primary air to be effectively tempered by mixing with warmer secondary air from the room, reducing the cooling power required while maintaining efficient temperature control
3Stability of the object's composition
If free-jet injection of primary air is used to mix with room air, then mixing is achieved, but turbulence and noise increase
Solution Approach 1:
The ceiling cavity acts as an intermediary zone that enables air mixing without the harmful effects of free-jet injection. Primary air flows along the ceiling cavity in a controlled manner and mixes with secondary air drawn through the suspended ceiling, achieving stable air composition without turbulence or noise
Solution Approach 2:
The mixing process is relocated from the room volume (three-dimensional free-jet mixing causing turbulence) to the ceiling cavity (two-dimensional flow along the ceiling surface). This dimensional change enables laminar, controlled mixing that achieves air composition stability without generating turbulence or noise
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 achieves a more even and efficient temperature control with reduced turbulence and energy usage, utilizing the ceiling's thermal capacity for air conditioning, and allows for temperature regulation without creating drafts or the need for additional heating of primary air.
Implementation Method 1
a low-turbulence flow is achieved in the room at relatively low air velocities, and that the heating or cooling capacity of a floor slab is used for air conditioning - or more generally for temperature control - due to the mixing of the primary and secondary airflows in the space between the floor slab and the ceiling below
Implementation Method 2
the heating or cooling capacity of a floor slab is used for air conditioning - or more generally for temperature control - due to the mixing of the primary and secondary airflows in the space between the floor slab and the ceiling below
Data Source
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AI summary
The invention relates to a method for ventilating and controlling the temperature of rooms according to the principle of dilution ventilation, wherein a primary air flow (40) is introduced into the ceiling cavity (30) of a room (4), which room is partitioned off from the story ceiling (26) by a suspended ceiling (31), and said primary air flow is introduced into the room (4) via leaks (41, 42, 43) in the suspended ceiling (31), wherein the primary air flow (40) produces a secondary air flow (33) as an induction air flow in the ceiling cavity (30), which secondary air flow sucks a room air flow (32) from the room (4) into the ceiling cavity (30), mixes the room air flow with the secondary air flow (33), and introduces the room air flow into the room (4) as a tertiary air flow (34) via the leaks (41, 42, 43) in the suspended ceiling (31).