Fresh Air Mixing Control for Occupancy-Based Building Ventilation

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Solution Overview

Problem

Existing methods for controlling fresh air supply in buildings are inefficient, leading to increased operating costs due to unnecessary additional air requirements, which are influenced by temperature differences and pressure conditions, and fail to precisely match air supply to the number of people in the building.

Innovation Solution

Regulating the quantity of fresh air based on the mixed temperature of fresh air and circulating air, using a control device connected to a temperature sensor, allows for precise adjustment of fresh air supply, eliminating unnecessary air and compensating for fluctuations caused by pressure conditions, while also considering CO2 content to optimize energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an increased proportion of fresh air is supplied to compensate for temperature differences and pressure conditions, then the reliability of fresh air supply is improved, but the operating costs increase

Engineering Contradiction:

Improvefresh air supply reliabilityVSAvoidoperating costs

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The control device continuously monitors the actual fresh air quantity supplied and compares it with the target value. Based on this feedback, the control device adjusts the fresh air supply to eliminate deviations, ensuring reliable fresh air supply while avoiding unnecessary energy consumption from excessive fresh air supply.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the fresh air supply parameters based on measured values such as mixed air temperature, pressure conditions, and occupancy. By changing these parameters in real-time, the system maintains reliable fresh air supply while optimizing energy consumption and reducing operating costs.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If the fresh air supply is precisely matched to the number of people using occupancy sensors, then the operating costs are reduced, but the measurement precision requirements increase

Engineering Contradiction:

Improveoperating costsVSAvoidoccupancy detection precision

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The system uses mixed air temperature as an intermediary parameter to indirectly determine the required fresh air quantity. Instead of directly measuring occupancy with high-precision sensors, the control device calculates the needed fresh air based on temperature measurements and thermal balance considerations, reducing measurement precision requirements while still achieving cost-effective operation.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If additional fresh air is supplied to account for pressure condition fluctuations, then the reliability is improved, but unnecessary energy consumption increases

Engineering Contradiction:

Improvefresh air supply stabilityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The fresh air supply system dynamically adapts to changing pressure conditions by continuously measuring actual supply and comparing it with target values. The control device adjusts the supply in real-time based on measured deviations, maintaining supply stability without continuously over-supplying fresh air and wasting energy.

Inventive Principle:

Principle #15Dynamics

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 results in reduced operating costs and improved stability of fresh air supply, ensuring adequate ventilation with precise regulation of fresh air quantity, minimizing energy consumption and maintaining low costs.

Implementation Method 1

using a control device connected to a temperature sensor, allows for precise adjustment of fresh air supply

Methodology Applied

Scientific EffectTemperature measurement:

Implementation Method 2

different pressure conditions in the device can have an influence on the amount of fresh air actually supplied

Methodology Applied

Scientific EffectPressure condition influence on air supply: Pressure Gradient

Implementation Method 3

a quantity of fresh air to be mixed into the circulating air of the device is controlled in order to at least partly to generate a predetermined amount of supply air for the building

Methodology Applied

Scientific EffectAir mixing:

Data Source

PatentEP2527753B1Device and method for regulating a fresh air supply for a device for cooling, heating and/or ventilating a building

Publication Date: 2014.02.12 SES SPAR EURON SHOPPING CENTS

AI summary

A device and a method for regulating the supply of fresh air to a device (1) for cooling, heating, and/or ventilating a building (2) are presented, in which the quantity of fresh air to be mixed with the recirculated air (10) of the device (1) is regulated depending on the number of people in the building (2) in order to at least partially generate a predetermined quantity of supply air (7) for the building (2). To create advantageous process conditions, it is proposed that the quantity of fresh air (8) to be supplied is regulated depending on the mixing temperature of fresh air (8) and recirculated air (10), corresponding to the number of people in the building (2).