Sensor-Controlled Ventilation for Passive-Active Airflow Switching
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Solution Overview
Problem
Passive ventilation systems are energy efficient but uncontrollable, while active systems are costly to run and consume energy; existing systems struggle to maintain consistent airflow rates due to environmental conditions.
Innovation Solution
A ventilation system that automatically switches between passive and active modes using a sensor to control airflow with a damper arrangement and a controller, ensuring the airflow rate meets a target by activating a fan only when necessary, and modulating airflow with a combination of damper plates and a motor to maintain optimal airflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If passive ventilation is used, then energy consumption is reduced, but airflow rate becomes uncontrollable and inconsistent
Solution Approach 1:
The system dynamically switches between passive and active ventilation modes based on sensor feedback. The controller monitors actual airflow rate and automatically activates the fan when passive ventilation becomes insufficient, creating a dynamic adaptation to changing environmental conditions while maintaining energy efficiency.
Solution Approach 2:
A sensor provides feedback on the actual airflow rate to the controller. This feedback mechanism enables the system to detect when passive ventilation is insufficient and automatically switch to active mode, ensuring consistent airflow control while minimizing energy consumption through intelligent decision-making.
2Ease of operation
If active ventilation is used, then airflow rate is controllable, but energy consumption increases
Solution Approach 1:
The system applies active ventilation (fan activation) only partially and only when necessary, rather than continuously. The controller monitors airflow conditions and activates the fan solely when passive ventilation becomes insufficient, minimizing energy consumption while maintaining adequate airflow control.
Solution Approach 2:
The system serves itself by automatically detecting when active ventilation is needed through sensor feedback and switching modes accordingly. This self-regulating mechanism eliminates the need for continuous manual control or unnecessary fan operation, reducing energy consumption while maintaining airflow controllability.
3Loss of energy
If passive ventilation is used, then energy efficiency is improved, but ventilation rate varies with environmental conditions
Solution Approach 1:
The sensor continuously monitors actual airflow rate and provides feedback to the controller. When environmental conditions cause passive ventilation to become insufficient, the feedback mechanism triggers automatic fan activation, ensuring consistent ventilation performance while maintaining energy efficiency through conditional active ventilation.
Solution Approach 2:
The controller acts as an intermediary between the passive ventilation system and active fan. It monitors environmental impact on airflow through sensor feedback and mediates by activating the fan only when necessary, bridging the gap between energy-efficient passive ventilation and reliable active ventilation.
4Ease of operation
If damper plates are used to modulate airflow, then airflow rate control is improved, but device complexity increases
Solution Approach 1:
The damper plates are made movable and adjustable rather than fixed, allowing dynamic airflow modulation. The controller can adjust the damper positions based on sensor feedback to optimize airflow rates, providing improved control capability while keeping the mechanical adjustment mechanism relatively simple.
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 achieves energy-efficient operation by using passive ventilation when possible and activates the fan only when needed, maintaining controllable airflow rates and minimizing energy consumption by running the fan at the lowest necessary speed.
Implementation Method 1
a sensor for outputting a signal indicative of an actual air flow rate in the system
Implementation Method 2
The damper arrangement comprises a first damper plate that defines an aperture through which air flowing through the housing can flow and a second damper plate opposing the first damper plate and means for causing relative linear movement between the damper plates to vary the size of the area of the housing through in flows
Implementation Method 3
A typical active ventilation system uses one or more fans to generate a forced airflow through various ventilation ducts and vents in a building
Implementation Method 4
If indoor air temperatures are higher than outdoor air temperatures, the warmer and hence less dense indoor air tends to rise up through the ventilation ducts
Implementation Method 5
pressure differences resulting from temperature differences between indoor and outdoor air
Implementation Method 6
pressure differences resulting from wind flow passing over the building at the upper end of a duct
Data Source
Figure 1
Figure 2
AI summary
A ventilation system for ventilating an accommodation space, the ventilation system being operable in a passive ventilation mode and an active ventilation mode, the system comprising: a sensor for outputting a signal indicative of an actual air flow rate in the system; a controller for automatically turning on a ventilation fan to switch the system to the active ventilation mode if the actual air flow rate indicated by the sensor signal when the system is in the passive ventilation mode is unable to meet a target air flow rate, and wherein, in the passive ventilation mode and/or the active ventilation mode, the controller modulates the actual air flow rate in dependence upon the sensor's signal to attempt to make the actual air flow rate meet the target air flow rate.