HVAC vent valve
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Solution Overview
Problem
Existing air admittance valve systems are either costly and inefficient due to reliance on electric components or lack sensitivity to pressure changes, leading to ineffective ventilation and potential heat loss or gain, as they fail to automatically and reliably allow ambient air to enter buildings under negative pressure while preventing positive pressure air from escaping.
Innovation Solution
A gravity-activated air admittance valve with a thin, flexible sealing membrane and a cold air trap basin that automatically opens to allow ambient air entry during negative pressure conditions, while preventing warm air from entering during positive pressure conditions, utilizing a diaphragm and annular valve seat configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If electric components are used to control vents, then the vent can be opened and closed, but the system becomes costly and time-consuming to install
Solution Approach 1:
The vent assembly performs self-service by using the pressure differential itself to activate the membrane opening mechanism. When negative pressure occurs inside the building, the pressure difference automatically causes the membrane to deform and open the vent, eliminating the need for external electric control systems, motors, or power sources.
Solution Approach 2:
The patent replaces complex electric control systems with a simple mechanical response mechanism. The flexible membrane directly responds to pressure changes through elastic deformation, converting pressure differential energy into mechanical opening action without requiring electrical components, controllers, or power supplies.
2Device complexity
If manual means are used to open vents, then the system is simple, but the vent is not sensitive to pressure change and cannot open at the precise time ventilation is required
Solution Approach 1:
The flexible membrane acts as a pressure-sensitive feedback element that continuously monitors the pressure differential between indoor and outdoor environments. When the pressure difference reaches a threshold that causes membrane deformation, the vent automatically opens, providing real-time responsive control based on actual ventilation needs without manual intervention.
3Loss of energy
If the vent is left closed, then heat is retained, but ventilation is ineffective when negative pressure occurs
Solution Approach 1:
The vent assembly transitions from a static closed state to a dynamic responsive state. The flexible membrane allows the vent to adapt its opening status based on real-time pressure conditions, remaining closed during normal operation to retain heat and automatically opening when negative pressure requires ventilation, thus dynamically optimizing both energy retention and ventilation effectiveness.
4Strength
If a thick membrane is used, then sealing strength is improved, but the membrane cannot respond sensitively to low pressure differentials
Solution Approach 1:
The patent optimizes the membrane parameters by selecting appropriate thickness, material properties, and structural configuration. The membrane is designed with controlled thickness and elastic characteristics that enable it to deform and open the vent at very low pressure differentials (as low as 0.02 inches of water column) while maintaining adequate sealing capability when closed.
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 solution provides reliable, automatic, and efficient air admittance under low pressure conditions, ensuring compliance with building codes and preventing heat loss or gain by allowing ambient air to equalize pressure differentials while maintaining indoor air quality.
Implementation Method 1
A flexible membrane is provided for sealing against the sealing surface of the annular valve seat. The membrane provides reliable sealing at low pressure differentials.
Implementation Method 2
The air admittance valve utilizes a very low-pressure seal that is gravity activated, and a basin that acts as a cold air trap.
Implementation Method 3
a basin that acts as a cold air trap. The cold air trap prevents warm outside air from entering the valve body and lifting the membrane.
Data Source
AI summary
An air admittance valve, particularly for use in building ventilation, to close a duct when there is at least atmospheric pressure in the building, but to open to admit atmospheric air to the building upon the occurrence of even a very small less-than-atmospheric pressure in the building. The valve has a hollow body with an upward opening to outside the building, and the low point of the body forming a basin, and a valve seat about an upward opening to inside the building. A valve member in the body above the basin opens and closes the upward opening to inside the building, and the valve member is guided in alignment with the valve seat.