Cloud-Based VAV HVAC Damper Control to Prevent Pressure Damage
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Solution Overview
Problem
Variable air volume HVAC systems face instability and noise issues due to the closing of dampers, and retrofitting with bypass dampers or variable speed fans is often not feasible, especially in existing installations.
Innovation Solution
A cloud-based HVAC control system that uses actuator-driven valves and sensors to adjust air flow by calculating and transmitting minimum damper positions and fan speeds through a telecommunications network, eliminating the need for bypass dampers or variable speed fans.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If all dampers are closed in a VAV HVAC system, then energy consumption is reduced, but mechanical damage to duct work occurs and noise level becomes unacceptable
Solution Approach 1:
The system continuously monitors system pressure via pressure sensors and feeds this information back to the controller. The controller dynamically adjusts damper positions based on real-time pressure feedback to prevent excessive pressure buildup that would cause mechanical damage, while still allowing dampers to close sufficiently to reduce energy consumption.
Solution Approach 2:
The system transitions from static damper positioning to dynamic adjustment. The controller continuously modifies damper positions based on real-time pressure conditions, allowing the system to adaptively balance energy savings with prevention of mechanical damage to duct work.
2Loss of energy
If all dampers but one are closed, then energy consumption is reduced, but regulation of flow becomes increasingly difficult due to excess system pressure
Solution Approach 1:
The pressure feedback mechanism enables the controller to detect excess system pressure and respond by adjusting remaining open dampers to appropriate positions, maintaining proper flow regulation even when most dampers are closed for energy savings.
Solution Approach 2:
The system changes the operating parameters of remaining open dampers dynamically based on pressure conditions. When pressure becomes excessive, the controller adjusts the position parameters of open dampers to restore proper pressure and flow regulation.
3Ease of operation
If a bypass damper is added to maintain system pressure, then flow regulation is improved, but device complexity increases and retrofitting becomes difficult
Solution Approach 1:
The existing dampers in the system are made self-regulating through electronic control. Each damper can independently adjust its position based on pressure feedback, eliminating the need for additional bypass dampers or complex mechanical pressure-regulating devices.
Solution Approach 2:
The patent replaces mechanical pressure-regulating mechanisms (such as bypass dampers) with an electronic control system that uses sensors and actuators to dynamically adjust damper positions, reducing mechanical complexity while improving flow regulation.
4Measurement precision
If flow sensors are implemented in air ducts to obtain pressure-independence, then flow control precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces mechanical flow sensors with electronic pressure sensors and uses computational algorithms to calculate flow information from pressure data, reducing hardware complexity while maintaining measurement precision.
Solution Approach 2:
The system changes from direct flow measurement to indirect flow determination through pressure measurement and calculation. This parameter substitution allows flow control precision to be achieved through computational methods rather than additional physical sensors.
Data Source
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AI summary
For controlling the flow of air into the zones (Z1, Z2, Z3, Zi) of a variable air volume HVAC system (1) having actuator driven dampers (D1, D2, D3, Di), which operate in a range from a minimum damper position to a maximum damper position for adjusting the flow of air into a zone (Z1, Z2, Z3, Zi), flow measurement values and current damper positions are transmitted via a telecommunications network (2) to a cloud-based HVAC control center (3). Using the flow measurement values and calibration values, which indicate HVAC system parameters at a defined calibration pressure in the HVAC system (1) and at different damper positions, the cloud-based HVAC control center (3) calculates the minimum damper position for the actuators (A1, A2, A3, Ai), such that the pressure in the HVAC system (1) does not exceed a defined maximum pressure threshold, and transmits the minimum damper position to the actuators.