Return Air Mixing Layout With Sequential Fan and Damper Control

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Solution Overview

Problem

Existing air conditioning systems that mix return air with incoming air using a combination of ingoing and off air fans with slide valves result in unnecessary high electrical energy consumption due to the return air passing both fans and the ingoing air flow being constantly controlled at maximum levels, even when only a maximum heating or cooling effect is required.

Innovation Solution

Mechanically separate and individually regulate the slide valves, with the off air fan placed subsequent to the return air slide valve, and utilize speed-controlled fans and pressure measuring means to optimize air flow, allowing the return air to pass only the ingoing air fan, thereby reducing energy demand by adjusting fan speeds and valve openings based on actual air flow needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If return air is mixed into incoming air using both ingoing air fan and off air fan with slide valves, then return air admixture is achieved, but electrical energy consumption increases unnecessarily

Engineering Contradiction:
Improveelectrical energy consumptionVSAvoidreturn air admixture control
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The invention extracts the off air fan from the return air mixing path, placing it only in the off air channel. The return air slide valve is positioned before the off air fan, allowing return air to bypass the off air fan entirely and mix with incoming air only through the ingoing air fan, thereby eliminating unnecessary energy consumption while maintaining mixing functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention segments the air handling system into distinct paths: the off air fan handles only off air extraction, while the ingoing air fan handles both incoming air and return air mixing. This segmentation allows each fan to operate independently and efficiently, reducing overall energy consumption.

Inventive Principle:
Principle #1Segmentation

2Power

If ingoing air flow is controlled at maximum levels constantly, then heating or cooling effect is maximized, but electrical energy consumption increases

Engineering Contradiction:
Improveheating or cooling effectVSAvoidelectrical energy consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The invention implements dynamic control of the ingoing air fan speed based on actual system needs. The fan speed is adjusted according to the position of the return air slide valve and the required heating or cooling effect, allowing the system to operate at optimal power levels rather than constant maximum levels, thereby reducing energy consumption while maintaining effectiveness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the operating parameters of the ingoing air fan from constant maximum speed to variable speed control. By adjusting fan speed as a parameter based on return air mixture requirements and thermal load, the system achieves both heating/cooling effects and energy efficiency.

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 solution significantly reduces electrical power consumption by minimizing the energy required for the off air fan, allowing for precise adjustment of air flows to meet heating or cooling demands, while ensuring efficient operation and reducing unnecessary energy usage.

Implementation Method 1

an ingoing air fan (11) arranged in an ingoing air channel (21)

Methodology Applied
Scientific EffectFan: Fan

Implementation Method 2

an off air fan (12) arranged in an off air channel (22)

Methodology Applied
Scientific EffectFan: Fan

Implementation Method 3

a heat exchanger (10) having an ingoing air channel (21) and an off air channel (22)

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2135011B1Air conditioning equipment for return air
Publication Date: 2016.11.16 SWEGON AB
  • EP2135011B1 patent drawingFigure 1
  • EP2135011B1 patent drawingFigure 2

AI summary

Air conditioning equipment for return air admixture of off air into ingoing air comprising means for out door airflow, return airflow, off airflow, and ingoing airflow, whereby it comprises a control and regulating system with a monitoring and calculation unit arranged, based on one or more sensors present in the building to individually regulate speed controllable fans (11, 12) to provide a desired return air admixture, that a first air flow means (14) is regulated in sequence with a second air flow (15) means, whereby when said second airflow means (15) is regulated to a required degree of opening. The fan section (12) of the off air stream is placed in the air flow direction subsequent to the section (23) for return air flow.