Ceiling Swirl Diffuser with Damper Compartment for VAV Airflow Control
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Solution Overview
Problem
Existing variable air volume (VAV) diffusers face challenges in maintaining consistent airflow rates and thermal comfort due to issues with static pressure measurement, airflow noise, and limited space for induction systems, leading to inefficiencies and increased energy consumption.
Innovation Solution
A diffuser unit with a pressure plenum, air deflector, and damper compartment that maintains constant velocity and throw of air, featuring a swirl discharge mechanism and adjustable damper doors to optimize airflow and reduce noise, while also incorporating a perforated baffle plate and induction system for improved air mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high airflow rates are used in standard ceiling diffusers, then cooling capacity is improved, but air throw increases causing over-throw and draughts
Solution Approach 1:
The diffuser incorporates adjustable vanes that can dynamically change the discharge angle and direction of air streams. This allows the system to adapt the air throw characteristics in response to varying airflow rates, preventing over-throw and draughts while maintaining high cooling capacity when required.
Solution Approach 2:
The diffuser design creates multiple discrete air streams with different discharge angles and velocities through separate discharge outlets. This local differentiation allows certain streams to reach further while others provide localized cooling, preventing the harmful uniform over-throw associated with standard diffusers.
2Use of energy by moving object
If low airflow rates are used in standard ceiling diffusers, then energy consumption is reduced, but air throw decreases causing zones of stagnation and increased air temperature
Solution Approach 1:
The adjustable vanes enable the diffuser to optimize air stream trajectories at low airflow rates, directing air more effectively to reach stagnant zones. This dynamic adjustment maintains temperature distribution uniformity even when overall airflow is reduced for energy savings.
Solution Approach 2:
The diffuser employs asymmetric discharge patterns with different air streams directed at varying angles and velocities. This asymmetry allows low airflow rates to be distributed more strategically, penetrating stagnant zones that would otherwise experience temperature buildup.
3Loss of energy
If VAV turndown is increased to reduce minimum airflow rate, then fan energy savings are improved, but discharge velocity decreases causing dumping and discomfort
Solution Approach 1:
The adjustable vanes allow the diffuser to compensate for reduced discharge velocity at low airflow rates by optimizing the discharge angle and direction. This dynamic adjustment prevents air dumping and maintains thermal comfort while enabling greater VAV turndown for fan energy savings.
Solution Approach 2:
The system changes the discharge parameters (angle, direction, distribution pattern) in response to varying airflow rates. This parameter adjustment maintains effective air delivery and prevents dumping even when discharge velocity is reduced due to lower airflow rates.
4Temperature
If fixed vane ceiling swirl diffusers are used to improve thermal comfort, then air mixing is improved, but minimum airflow rate remains high causing energy waste
Solution Approach 1:
The adjustable vanes allow the diffuser to maintain effective air mixing and temperature distribution uniformity across a wider range of airflow rates. This dynamic control enables the system to achieve thermal comfort with lower minimum airflow rates compared to fixed vane designs.
Solution Approach 2:
The diffuser divides the air stream into multiple discrete streams with different trajectories and mixing characteristics. This segmentation allows effective air distribution and temperature uniformity to be achieved with lower overall airflow rates by optimizing each segment's contribution.
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 solution enhances airflow control and thermal comfort by maintaining consistent air throw and velocity, reducing energy consumption, and minimizing airflow noise, while allowing for flexible installation in restricted ceiling spaces.
Implementation Method 1
a swirl diffuser that discharges air in a swirl in a plane substantially parallel to a face of the diffuser
Implementation Method 2
The highly inductive swirl discharge of ceiling swirl diffusers draws in and mixes large quantities of room air into the discharged supply air stream
Implementation Method 3
a damper compartment with a plurality of damper doors that can be adjusted to control an airflow rate through the diffuser unit, each damper door associated with a corresponding aperture and being operable between an open position and a closed position
Implementation Method 4
the air deflector forming an outlet to the pressure plenum... disperses the discharged air in a plane substantially parallel to a discharge face of the diffuser unit
Data Source
AI summary
A diffuser unit having a damper compartment with a plurality of damper apertures. The damper apertures are open or closed by respective damper doors to induce a swirl to air exiting the diffuser via an air deflector which may be a diffuser with diffuser blades or a perforated plate. Alternative embodiments relate to a method of diffusing an airflow and a method of determining an airflow rate for a diffuser unit.