Bypass Humidifier Damper Control for Pulsed Water Saving
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Solution Overview
Problem
Conventional humidifiers in HVAC systems waste water and energy by delivering water continuously to the humidifier pad during a call for humidity, leading to inefficiencies and increased water drainage, even when the humidity levels are maintained, resulting in a high ratio of drained water to evaporated water.
Innovation Solution
Implementing a pulsed water delivery pattern to the humidifier pad, where water is delivered for only a portion of the call for humidity time, such as a 50% duty cycle, and using a controller to modulate the water flow rate and frequency based on humidity demand, reducing unnecessary water usage and maintaining effective humidity transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If water is delivered continuously to the humidifier pad during a call for humidity, then the humidifier maintains humidity levels, but water waste increases and energy consumption increases
Solution Approach 1:
The patent applies periodic action by delivering water to the humidifier pad in pulsed cycles rather than continuously. The controller opens the water valve for specific time intervals (e.g., 10 seconds on, 50 seconds off) during a humidifier call, creating a periodic water delivery pattern that maintains humidity while significantly reducing water waste and energy consumption associated with continuous hot water delivery.
2Productivity
If water is delivered continuously to the humidifier pad, then effective humidity transfer is maintained, but energy consumption increases due to continuous hot water usage
Solution Approach 1:
The system uses periodic water delivery where the water valve operates in cycles during humidifier calls. This periodic action maintains sufficient moisture on the humidifier pad for effective humidity transfer while eliminating the energy waste of continuously heating and delivering water when the pad already has adequate moisture.
Solution Approach 2:
The controller dynamically changes the water delivery parameters by adjusting the duty cycle (ratio of on-time to total cycle time) based on system conditions. This parameter modification allows optimization of both humidity transfer effectiveness and energy efficiency by adapting water delivery to actual humidification needs rather than using fixed continuous delivery.
3Loss of substance
If a damper blocks the air path after humidifier operation ends, then water waste is reduced, but air flow control complexity increases
Solution Approach 1:
The damper operates periodically by blocking the air path after a humidifier call ends, creating an on-off control pattern. This periodic damper action prevents bypass air from carrying away moisture and causing water waste, while the simple binary control state (open during call, closed after call) maintains relatively low system complexity.
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
This approach reduces water waste, conserves energy by minimizing continuous hot water usage, and maintains targeted humidity levels while extending the lifespan of water control valves, resulting in a more efficient and cost-effective humidification process.
Implementation Method 1
Evaporative humidifiers are widely used in conjunction with forced air residential and commercial heating, ventilation, and air conditioning (HVAC) systems. Some evaporative humidifiers direct air from an air stream of an HVAC system, through a moistened humidifier pad
Data Source
AI summary
An improved humidifier system for adding humidity to an air stream of an HVAC system. The humidifier system includes an air path that is configured to accept air from a first HVAC duct and return air to a second HVAC duct. A damper is disposed in the air path to selectively substantially block the flow of air in the air path, or to substantially not block the flow of air in the air path. In some cases, the damper may be a motorized damper, and the humidifier system may include a controller that is configured to cause the motorized damper to not substantially block the flow of air in the air path during a call for humidifier operation, and to substantially block the flow of air in the air path after the call for humidifier operation ends. Alternatively, the damper may be manually actuated, and an HVAC controller may be configured to notify when the damper should be moved (e.g. between seasons).