Fresh Air Intake Damper Control Using Negative Pressure

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Solution Overview

Problem

Existing fresh-air cooling systems for buildings rely on open windows and doors for air intake, which is inconvenient, insecure, and inefficient, especially for inner rooms without direct access to the outside environment.

Innovation Solution

A fresh-air cooling system with an exterior interface assembly, damper, register, and motorized fan that creates negative static pressure to automatically open and control air intake through adjustable air intake assemblies, allowing secure and convenient regulation of fresh air flow without opening windows or doors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If windows or doors are left ajar for fresh air intake, then fresh air volume increases, but security risk increases

Engineering Contradiction:

Improvefresh air volumeVSAvoidsecurity

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent introduces an automated air intake assembly with a motorized damper as an intermediary device between the interior and exterior environments. This damper can be remotely opened or closed to control fresh air intake without requiring physical windows or doors to be left ajar, thereby maintaining security while enabling ventilation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical system of manually opening/closing windows or doors with an automated motorized damper system controlled by a fan and pressure differential. The damper automatically opens when negative pressure is generated by the fan and closes when pressure equalizes, eliminating the need for manual operation and maintaining security.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Use of energy by moving object

If whole house fan is used for cooling, then energy efficiency improves, but user presence is required to operate

Engineering Contradiction:

Improveenergy efficiencyVSAvoiduser presence requirement

Core Design Contradiction:

Use of energy by moving objectVSEase of operation

Solution Approach 1:

The patent implements a self-service system where the motorized damper automatically responds to pressure changes generated by the fan. When the fan creates negative pressure, the damper automatically opens to allow fresh air intake; when pressure equalizes, the damper automatically closes. This eliminates the need for user presence or manual operation.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system uses pressure differential as feedback to control damper operation. The damper's position is automatically adjusted based on the pressure difference between interior and exterior environments, creating a closed-loop control system that operates autonomously without user intervention.

Inventive Principle:

Principle #23Feedback

3Quantity of substance

If ventilation fan with fixed CFM is used, then fresh air intake is provided, but fresh air volume cannot be adjusted

Engineering Contradiction:

Improvefresh air intakeVSAvoidfresh air volume control

Core Design Contradiction:

Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent transforms the fixed CFM ventilation system into a dynamic system by introducing a motorized damper that can automatically adjust its opening degree based on pressure differential. This allows the fresh air volume to be dynamically controlled in response to changing environmental conditions and fan operation, providing adaptability without requiring multiple fixed-CFM fans.

Inventive Principle:

Principle #15Dynamics

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

Enables secure, convenient, and efficient control of fresh air intake, ensuring effective cooling of all rooms within a building structure by automatically adjusting air flow based on pressure differences and user preferences, enhancing energy efficiency and security.

Implementation Method 1

pull air from the living space into the attic at an airflow rate that is sufficient to create in the living space a negative static pressure that exceeds the cracking pressure of the damper

Methodology Applied

Scientific EffectNegative static pressure: Pressure Gradient

Implementation Method 2

The biasing element is further configured to allow the moveable flap to move to an open configuration in response to a cracking pressure being applied across the damper

Methodology Applied

Scientific EffectCracking pressure: Pressure Gradient

Data Source

PatentUS11802698B2Systems and methods for controlling and adjusting volume of fresh air intake in a building structure

Publication Date: 2023.10.31 QC MFG

AI summary

A fresh-air cooling system and methods of cooling a building structure with the same are provided. The system has an exterior interface assembly, a damper, a register, a duct, and a motorized fan. The exterior interface assembly is connected to the register by the duct and provides a flow path for air outside the building to enter the duct. The motorized fan is disposed in an attic of the building structure and pulls air into the attic from a living space to create a negative static pressure in the living space. The damper is positioned along the flow path from the exterior interface assembly to the living space and opens to allow air outside the building structure to enter the living space in response to motorized fan creating in the living space a negative static pressure that exceeds the cracking pressure of the damper. The cracking pressure of the damper can be adjusted to control the flow rate of outside air through the damper.