Cold End Header Box Pressure Conditioning for Multi-Size Furnaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
HVAC systems, particularly gas-fired furnaces, face challenges in maintaining consistent combustion pressure across varying furnace sizes, requiring multiple pressure switches and complex controller firmware, which complicates manufacturing and troubleshooting.
Innovation Solution
An integrated combustion pressure conditioning system within a Cold End Header Box (CEHB) regulates air flow and conditions combustion pressure, allowing a single pressure switch to monitor flow across multiple furnace models, simplifying manufacturing and reducing costs by standardizing gas valve usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple pressure switches are used to monitor combustion pressure across varying furnace sizes, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by introducing a pressure conditioning system that modifies the pressure signal parameters (pressure differential magnitude) to a standardized range. The conditioning system includes a restriction orifice and pressure equalization chamber that transform varying pressure signals from different furnace sizes into a uniform pressure range suitable for a single pressure switch, thereby maintaining measurement precision while reducing device complexity
Solution Approach 2:
The patent implements universality by designing a pressure conditioning system that enables a single pressure switch to serve multiple furnace models with varying sizes and combustion rates. The conditioning system acts as a universal interface that adapts different pressure sources to a common monitoring standard, eliminating the need for multiple specialized pressure switches and simplifying controller firmware requirements
2Adaptability or versatility
If components are sized to handle the range of furnace inputs, then adaptability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs an intermediary approach by introducing a pressure conditioning system as a mediator between the diverse pressure sources from different furnace sizes and the standardized pressure switch input. This intermediary system includes adjustable restriction orifices and pressure equalization chambers that can be tuned to accommodate various furnace configurations, providing adaptability while maintaining manageable manufacturing precision requirements through adjustment mechanisms rather than tight tolerances
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 integrated system ensures consistent combustion pressure monitoring and flow control across different furnace models, reducing manufacturing and troubleshooting costs, and minimizing the risk of clogging and external component complexity.
Implementation Method 1
bleed ports configured to reduce a pressure received through the negative channel supply port at the inlet to a targeted range at the negative pressure port
Implementation Method 2
a fixed orifice configured to regulate air flow through a heat exchanger of the furnace
Data Source
AI summary
A CEHB, a furnace and a method of constructing a furnace are disclosed. In one embodiment, the CEHB includes: (1) a fixed orifice configured to regulate air flow through a heat exchanger of the furnace, wherein a combustion air inducer induces the air flow and (2) a negative pressure channel including a negative channel supply port that communicates with an inlet of the combustion air inducer, a negative pressure port configured to connect to a negative input port of a pressure switch and bleed ports configured to reduce a pressure received through the negative channel supply port at the inlet to a targeted range at the negative pressure port, the pressure switch configured to monitor a combustion pressure through the heat exchanger.