Air-Conditioning Control System with Odor-Based Ventilator Suspension
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Solution Overview
Problem
Existing air-conditioning control systems decrease indoor air quality by suctioning and supplying outside air containing offensive odor substances, even when their concentration exceeds a threshold, leading to discomfort and poor indoor air quality.
Innovation Solution
An air-conditioning control system that includes a ventilator and an air-conditioning apparatus connected in series, equipped with sensors to detect offensive odor substances, temperature, and humidity, which adjusts the ratio of return air to outside air and operates the ventilator accordingly to prevent the introduction of contaminated outside air when concentrations exceed a threshold, ensuring all return air is used when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the ventilator operates in non-heat exchange ventilation mode to supply outside air for cooling, then outside-air cooling effect is achieved, but indoor air quality deteriorates when outside air contains high concentration of offensive odor substances
Solution Approach 1:
The controller continuously monitors the concentration of offensive odor substances in outside air through the sensor and adjusts ventilator operation accordingly. When the concentration exceeds the threshold, the controller suspends ventilator operation to prevent introducing contaminated air, while maintaining air-conditioning apparatus operation to ensure continuous supply of clean, cooled air to the controlled space.
Solution Approach 2:
The air-conditioning apparatus serves as an intermediary between the outside environment and the controlled space. It processes outside air through cooling and conditioning before supplying it to the indoor space, thereby filtering out harmful odor substances while maintaining the cooling effect. The system uses the air-conditioning apparatus as a buffer to prevent direct introduction of contaminated outside air.
2Object-affected harmful factors
If the ventilator suspends operation to prevent introduction of contaminated outside air, then indoor air quality is maintained, but outside-air cooling effect is lost
Solution Approach 1:
The system merges the functions of the ventilator and air-conditioning apparatus into a coordinated operation. When the ventilator suspends operation due to high odor substance concentrations, the air-conditioning apparatus continues to operate and processes return air or available clean air sources to maintain cooling. The controller integrates both systems to ensure that cooling function is preserved even when ventilation is temporarily suspended.
3Use of energy by moving object
If the air-conditioning apparatus operates in air-sending mode with mixed outside air and return air, then energy efficiency is improved through outside-air cooling, but control complexity increases due to multiple operation modes
Solution Approach 1:
The control system dynamically adjusts operation modes based on real-time sensor readings of offensive odor substance concentrations and temperature conditions. The controller automatically transitions between different operational states (ventilation mode, cooling mode, suspended mode) according to environmental conditions, optimizing energy efficiency without requiring manual intervention. This dynamic adaptation simplifies user interaction while maintaining complex control logic internally.
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
Prevents a decrease in indoor air quality by suspending the operation of the ventilator and redirecting all return air to the air-conditioning apparatus when offensive odor substance concentrations exceed thresholds, maintaining comfort and air quality within the indoor space without altering the supply air quantity.
Implementation Method 1
a ventilation total heat exchanger configured to exchange heat between the outside air and the return air suctioned in the ventilator
Implementation Method 2
the controller performs cooling when determining that the temperature of the indoor room detected by the indoor temperature sensor is higher than a predetermined upper-limit dry-bulb temperature
Data Source
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AI summary
An air-conditioning control system includes an air-conditioning apparatus to supply an indoor room with supply air and a ventilator to replace return air flowing from the indoor room with outside air. The air-conditioning apparatus is connected in series with the ventilator such that the outside air flowing from the ventilator and the return air flowing from the indoor room are supplied to the air-conditioning apparatus. The air-conditioning control system further includes a return air (RA) branch damper to adjust a ratio of the return air supplied to the air-conditioning apparatus to the return air supplied to the ventilator, a specified offensive odor substance sensor to detect a concentration of a specified offensive odor substance, and a controller to operate the ventilator and control the RA branch damper such that a relationship of the return air = the supply air - the outside air is satisfied when the controller determines that the concentration of the specified offensive odor substance detected by the specified offensive odor substance sensor is less than or equal to a predetermined threshold and to suspend operation of the ventilator and control the RA branch damper such that all the return air is supplied to the air-conditioning apparatus when the controller determines that the concentration of the specified offensive odor substance detected by the specified offensive odor substance sensor is greater than the predetermined threshold.