Multi-Unit A/C Humidity Control by Latent Load Redistribution

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In multiple unit air conditioning systems, the 'zoning' effect of sensible heat leads to imbalanced heat load distribution among units, causing inefficient operation, where units with inadequate sensible heat loads must provide excessive cooling, necessitating heating to maintain humidity control, resulting in inefficient use of units.

Innovation Solution

An air conditioning system with multiple units and a controller that senses humidity and heat loads, redistributes latent heat removal to ensure no unit exceeds its sensible heat removal capacity, optimizing operation by reallocating latent heat loads to units with higher sensible heat loads, thereby eliminating the need for heating in any zone.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If each A/C unit operates independently to maintain temperature control in its zone, then temperature control is maintained, but humidity control becomes inefficient requiring heating operation

Engineering Contradiction:
Improvetemperature controlVSAvoidenergy efficiency
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent merges humidity control functionality across multiple A/C units by allowing one unit to serve as a dedicated humidity controller for the entire room. This unit removes latent heat (moisture) independently of its sensible heat (temperature) zone, while other units focus on temperature control. This combination resolves the contradiction by enabling efficient humidity control without requiring heating operations in units with insufficient sensible heat loads.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The designated humidity control A/C unit performs multiple functions: it controls humidity for the entire room (universal humidity control) while also maintaining temperature in its own zone. This multi-functionality allows the system to achieve both temperature control and efficient humidity control without the energy waste of heating operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a unit with low sensible heat load provides cooling for humidity control, then humidity control is achieved, but the unit must operate inefficiently requiring heating to balance temperature

Engineering Contradiction:
Improvehumidity controlVSAvoidenergy waste
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent combines the humidity control function with a unit that has sufficient sensible heat load capacity. This designated unit removes latent heat for the entire room while its sensible heat removal capacity is adequate to prevent temperature drops requiring heating. This merging of functions eliminates energy waste by ensuring humidity control is performed by a unit that can handle the cooling load efficiently.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If latent heat removal is distributed evenly among all units, then humidity control is maintained, but units with insufficient sensible heat load operate inefficiently

Engineering Contradiction:
Improvehumidity controlVSAvoidoperational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by designating specific A/C units for specific functions based on their capabilities. One unit is designated for humidity control (with sufficient sensible heat load), while other units focus on temperature control in their respective zones. This localized specialization ensures that humidity control is reliable while maintaining high operational efficiency across all units.

Inventive Principle:
Principle #3Local quality

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 approach ensures all units operate efficiently, maintaining humidity control across zones without requiring heating, improving overall system efficiency by preventing units from operating in heating mode, thus optimizing energy use and performance.

Implementation Method 1

This is due to the effect of vapor pressure created by the moisture in the air. This vapor pressure will force the moisture to distribute evenly within the room 10 independent of the air flow of the A/C units 12, 14 and 16.

Methodology Applied
Scientific EffectVapor pressure: Vapour Pressure

Implementation Method 2

the majority of heat flow, which is controlled by convection, often stays within the zone determined by the air flow of the individual A/C units

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

Latent cooling is the removal of moisture or humidity from the air

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2286157B1Improved humidity control for multiple unit a/c system installations
Publication Date: 2018.08.08 VERTIV CORP
  • EP2286157B1 patent drawingFigure 1~2
  • EP2286157B1 patent drawingFigure 3~4
  • EP2286157B1 patent drawingFigure 5

AI summary

An air conditioning (A/C) system that may have a plurality of air conditioning units disposed in different zones of an area that each operate to cool the different zones, a humidity sensor for sensing the humidity in the area, and a controller. The controller may be adapted to analyze a sensible heat load being experienced by each of the air conditioning units and to control a latent heat removal being performed by each air conditioning unit such that a percentage of latent heat removal performed by each air conditioning unit does not exceed a percentage of sensible heat removal being performed by each air conditioning unit.