Multi-Positional Plenum Fan Box for Compact HVACR Airflow

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Solution Overview

Problem

HVACR systems using centrifugal blowers face obstruction issues that reduce airflow efficiency and heat exchange effectiveness, particularly in compact commercial applications where space is limited.

Innovation Solution

Incorporating one or more plenum fans within a fan box located between the indoor coil and the heat exchanger compartment, with adjustable orientations to minimize obstruction and enhance airflow, allowing for more efficient heat exchange and space utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If centrifugal blowers are used to drive air through the HVACR system, then air can be moved through the system, but the centrifugal blower obstructs the indoor coil and reduces airflow efficiency

Engineering Contradiction:

Improveairflow efficiencyVSAvoidobstruction of indoor coil

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful centrifugal blower from its traditional position and replaces it with plenum fans positioned in a fan box located between the indoor coil and heat exchanger compartment. This removes the obstruction caused by the centrifugal blower while maintaining the air moving function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary structure - a fan box containing plenum fans - positioned between the indoor coil and heat exchanger compartment. This intermediary arrangement allows air to be moved efficiently without the indoor coil obstruction problem caused by traditional centrifugal blowers.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If multiple plenum fans are installed in a fan box, then airflow efficiency and heat exchange are improved, but space constraints in light commercial applications make cabinet length reduction necessary

Engineering Contradiction:

Improveheat exchange efficiencyVSAvoidcabinet length

Core Design Contradiction:

ProductivityVSLength of moving object

Solution Approach 1:

The patent arranges multiple plenum fans vertically within the fan box, utilizing the vertical dimension to accommodate multiple fans without increasing cabinet length. This vertical stacking allows efficient heat exchange while maintaining compact horizontal footprint suitable for light commercial applications.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent nests multiple plenum fans within a compact fan box structure, with fans arranged vertically one above another. This nested arrangement allows multiple fans to occupy a small volume, improving heat exchange efficiency without significantly increasing overall cabinet dimensions.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Volume of stationary object

If the fan box is positioned between the indoor coil and heat exchanger compartment, then space is efficiently utilized and cabinet length is reduced, but the inlet orientation must be precisely angled to maintain proper airflow

Engineering Contradiction:

Improvecabinet space utilizationVSAvoidinlet orientation flexibility

Core Design Contradiction:

Volume of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent makes the fan box inlet orientation adjustable, allowing the inlet plane to be angled at ±35° degrees with respect to the indoor coil plane. This dynamic adjustability enables proper airflow patterns while accommodating the compact fan box positioning between the indoor coil and heat exchanger compartment.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent varies the inlet orientation parameter of the fan box, allowing adjustment of the inlet plane angle within ±35° degrees relative to the indoor coil plane. This parameter change enables optimization of airflow patterns while maintaining efficient space utilization in the compact cabinet configuration.

Inventive Principle:

Principle #35Parameter changes

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 configuration improves airflow efficiency, reduces cabinet length, and enhances heat exchange between air and the indoor coil, increasing the overall performance and refrigeration capacity of HVACR systems in constrained spaces.

Implementation Method 1

centrifugal blowers, particularly forward-curved scroll fans having logarithmic-type expansion housings

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentUS11333367B2HVACR system including multi-positional and multi-use plenum fans

Publication Date: 2022.05.17 TRANE INTERNATIONAL INC

AI summary

This disclosure relates generally to cabinets for commercial heating, ventilation, air conditioning and refrigeration (HVACR) systems. More particularly, this disclosure relates to HVACR cabinets including one or more plenum fans located in a fan box. The fan box may be located between an indoor coil and a heat exchanger compartment of an HVACR unit. The fan box may be configured to direct air into a heat exchanger compartment inlet. The fan box may be parallel with or angled with respect to the indoor coil.