HVAC Scrubber Control Using Occupancy-Based Filter Regeneration
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Solution Overview
Problem
HVAC systems face inefficiencies in maintaining air quality due to high levels of contaminants like carbon dioxide and volatile organic compounds in return air, which can reduce the operational efficiency of temperature adjustments when outside air temperature differs significantly from the setpoint.
Innovation Solution
A scrubber unit integrated with the HVAC system, featuring a contaminant filter that sorbs air contaminants under pressure and temperature differentials, and control circuitry that adjusts operation based on occupancy data and sensor readings to optimize filtering efficiency through regeneration modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If return air is used for supply air to improve energy efficiency, then temperature adjustment efficiency is improved, but contaminant level in supply air increases
Solution Approach 1:
The scrubber unit extracts and removes contaminants from return air through a contaminant filter that sorbs air contaminants when an elevated pressure differential is introduced across the filter. This allows the HVAC system to use return air for supply air while maintaining air quality by removing CO2, formaldehyde, and other volatile organic compounds before the air is redistributed.
Solution Approach 2:
The contaminant filter acts as an intermediary between return air and supply air, enabling the system to efficiently reuse return air while protecting against contaminant buildup. The filter mediates the air quality issue, allowing energy-efficient operation without compromising indoor air quality.
2Object-affected harmful factors
If outside air is used to reduce contaminant level, then air quality is improved, but temperature adjustment energy consumption increases
Solution Approach 1:
The scrubber unit enables the HVAC system to self-service its air quality needs by treating return air on-site, reducing the need to import outside air for contaminant control. The system serves itself by regenerating the contaminant filter and maintaining filtering efficiency, allowing energy-efficient operation with minimal outside air intake.
3Object-affected harmful factors
If contaminant filter operates continuously at high pressure differential, then contaminant removal efficiency is improved, but energy consumption increases
Solution Approach 1:
The scrubber control circuitry implements periodic regeneration cycles for the contaminant filter rather than continuous high-pressure differential operation. The system monitors filter loading and applies elevated pressure differential only when needed to desorb accumulated contaminants, reducing energy consumption while maintaining effective contaminant removal. The filter alternates between sorption mode and regeneration mode.
Solution Approach 2:
The system dynamically changes operating parameters by adjusting the pressure differential across the contaminant filter based on contaminant loading conditions. During normal operation, a lower pressure differential maintains sorption efficiency with minimal energy use. During regeneration, the pressure differential is elevated temporarily to desorb contaminants, then returned to normal operation.
4Adaptability or versatility
If scrubber unit integrates with building management system, then operational coordination is improved, but device complexity increases
Solution Approach 1:
The scrubber control circuitry is designed with multi-functionality, serving both as a standalone control system for the scrubber unit and as an integrated component of the building management system. The circuitry can operate independently using local sensors and control logic, or communicate with external BMS for coordinated operation across multiple building systems, enhancing versatility without requiring complete redesign.
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 scrubber unit effectively reduces contaminant levels in return air, enhancing the HVAC system's operational efficiency by minimizing the use of outside air and improving air quality, thereby optimizing temperature adjustments and reducing energy consumption.
Implementation Method 1
a contaminant filter that sorbs air contaminants from a surrounding environment when an elevated pressure differential is introduced across the contaminant filter
Data Source
AI summary
Systems and methods for integrating a building management system communicatively coupled to a security subsystem via a communication network, in which the building management system determines occupancy data, with a heating, ventilation, and air conditioning subsystem that includes a scrubber unit communicatively coupled to the building management system via the communication network. The scrubber unit includes a contaminant filter that sorbs air contaminants from a surrounding environment when an elevated pressure differential is introduced across the contaminant filter; an inlet sensor that determines sensor data indicative of contaminant level present in return air received by the scrubber unit from an internal portion of the building; and scrubber control circuitry that selectively instructs the scrubber unit to operate in one of multiple regeneration modes based at least in part on the occupancy data and the sensor data to facilitate improving filtering efficiency provided by the contaminant filter during subsequent operation.