Dynamic ventilation control for a building
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
HVAC systems face challenges in determining optimal ventilation rates that balance energy efficiency with the need to maintain indoor comfort and reduce indoor air contaminants, particularly during conditions like pandemics where increased ventilation is prioritized.
Innovation Solution
The system learns an environmental model based on tracked interior and exterior conditions to predict a maximum allowed ventilation rate that maintains comfort conditions, using this model to dynamically control the outdoor air ventilation damper.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the ventilation rate is increased to reduce the spread of pathogens and improve indoor air quality, then the HVAC system may lack the heating and/or cooling capacity to adequately condition the incoming fresh air, compromising occupant comfort
Solution Approach 1:
The system dynamically adjusts the ventilation rate based on real-time HVAC capacity assessment. The controller continuously monitors heating and cooling capacity availability, and modulates the outdoor air damper position accordingly, allowing maximum ventilation when capacity is available and reducing ventilation when capacity is constrained, thereby resolving the contradiction between pathogen reduction and comfort maintenance
Solution Approach 2:
The system changes the ventilation rate parameter dynamically based on HVAC capacity conditions. When heating/cooling capacity is sufficient, the ventilation rate is increased to reduce pathogens; when capacity is insufficient, the ventilation rate is reduced to maintain comfort, thus adapting the ventilation parameter to resolve the contradiction
2Productivity
If the ventilation rate is set too high given current indoor and outdoor conditions, then the HVAC system lacks the heating and/or cooling capacity to adequately condition the incoming fresh air, but if set too low, then the building is not adequately ventilated
Solution Approach 1:
The system implements feedback control by continuously monitoring HVAC heating and cooling capacity, outdoor air conditions, and indoor air quality, then adjusting the outdoor air damper position accordingly. This closed-loop control ensures ventilation effectiveness is maximized when capacity is available while preventing energy waste when capacity is constrained
Solution Approach 2:
The ventilation rate is made dynamic rather than static, adjusting in real-time based on HVAC capacity availability and outdoor conditions, thereby optimizing the balance between ventilation effectiveness and energy consumption
3Object-affected harmful factors
If fresh air ventilation is increased to reduce contaminants, then operating costs increase due to the need to heat and cool the additional fresh air
Solution Approach 1:
The system dynamically modulates the outdoor air damper position based on real-time assessment of HVAC capacity and contaminant levels, increasing ventilation when energy can be efficiently utilized and reducing ventilation when energy costs would be excessive, thereby resolving the contradiction between contaminant reduction and energy consumption
Data Source
AI summary
Appropriate ventilation for a building space while maintaining building comfort includes tracking one or more interior environmental conditions within the building space and one or more exterior environmental conditions outside of the building space during operation of the HVAC system. An environmental model for the building space is learned over time based at least in part on these tracked environmental conditions, where the environmental model predicts an environmental state of the building space in response to operation of the HVAC system under various interior and exterior environmental conditions. A maximum allowed ventilation rate that can be achieved without causing the HVAC system to compromise on any of one or more comfort conditions of the building space is predicted using the environmental model. The outdoor air ventilation damper of the HVAC system is then controlled to provide an appropriate ventilation up to or at the predicted maximum allowed ventilation rate.