Double-Wall Inner Shell for Air Handling Units in Cold Climates
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Solution Overview
Problem
Existing air handling units face issues with thermal bridging and condensate formation in low-temperature environments, leading to corrosion and hygiene problems, which current solutions like multilayer insulation or thick plastic sheets are costly and prone to manufacturing defects or increased weight.
Innovation Solution
A monolithic inner shell with double-wall segments and air pockets between walls, forming partitions between different air zones, reduces thermal conductivity and prevents condensate formation, using molded plastic for structural rigidity and durability, and accommodating larger heat exchanger wheels to minimize depth and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If multilayer multi-material sheets are used for insulation, then thermal bridging is reduced, but manufacturing cost increases and manufacturing defects occur
Solution Approach 1:
The patent employs a composite structure consisting of an inner shell, outer shell, and insulation layer with air pockets. This multi-layer composite design reduces thermal bridging while maintaining manufacturing feasibility. The air pockets within the insulation layer provide additional thermal resistance without requiring complex multi-material assembly, thus lowering manufacturing cost and defect risk compared to traditional multilayer multi-material sheets.
Solution Approach 2:
The insulation layer is strategically positioned at specific locations where thermal bridging is most problematic, such as between the inner and outer shells and at connection points. This localized insulation approach targets the most critical thermal pathways without requiring complete multilayer coverage throughout the entire structure, reducing both material cost and manufacturing complexity.
2Object-affected harmful factors
If thick plastic sheets are used for insulation, then thermal bridging is reduced, but weight increases
Solution Approach 1:
The insulation layer incorporates air pockets distributed throughout its structure, creating a porous configuration. Air is an excellent thermal insulator, and these trapped air pockets provide high thermal resistance per unit volume. This allows the use of thinner insulation material compared to solid plastic sheets, thereby reducing weight while maintaining effective thermal bridging prevention.
Solution Approach 2:
The combination of plastic material with air pockets creates a composite insulation structure that leverages the strength and formability of plastic while utilizing air's insulating properties. This composite approach achieves superior thermal performance with reduced material thickness and weight compared to solid plastic sheets of equivalent insulation value.
3Strength
If monolithic material is used for inner shell, then structural rigidity is improved, but thermal insulation decreases
Solution Approach 1:
The patent creates a composite system where the monolithic inner shell is combined with an insulation layer containing air pockets. The monolithic shell provides the necessary structural rigidity and strength, while the attached insulation layer compensates for the thermal bridging inherent in solid material construction. This composite approach allows each component to fulfill its primary function without compromise.
Solution Approach 2:
The thermal management function is segmented from the structural function. The monolithic inner shell handles structural requirements, while the separate insulation layer with air pockets handles thermal insulation. This functional segmentation allows optimization of each component for its specific purpose without the trade-offs inherent in attempting to achieve both properties in a single monolithic material.
4Productivity
If larger heat exchanger wheels are used, then heat exchange efficiency is improved, but unit depth increases
Solution Approach 1:
The patent optimizes the spatial arrangement of components to accommodate larger heat exchanger wheels without proportionally increasing overall depth. By strategically positioning the heat exchanger wheels and utilizing the three-dimensional space within the inner shell, the design achieves efficient heat exchange while controlling the depth dimension through clever spatial configuration rather than simply scaling all dimensions proportionally.
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 effectively reduces thermal bridging and condensate formation, enhancing structural rigidity and insulation while being cost-effective and resistant to corrosion, thus improving the performance and reliability of air handling units in cold climates.
Implementation Method 1
double-wall segments with air pockets between said walls forming partitions between different air zones
Implementation Method 2
using molded plastic for structural rigidity and durability
Data Source
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AI summary
According to one aspect of the invention, object of the invention is inner shell for an air handling unit for operation in low temperature environmental conditions. The inner shell comprises two monolithic half-frames preferably made of plastic by molding. The half-frames comprise double-wall partitions with air pockets. The partitions are disposed between cold air pathways and warm air pathways eliminating cold bridging and avoiding water vapor condensation on walls of said pathways.