125963076 9 Training HVAC Ventilation

7/29/2019 125963076 9 Training HVAC Ventilation

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HVAC

Air Handling & Air Conditioning


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Schneider Electric 2- Division - Name Date

Agenda

Introduction to VentilationSingle and Double Flow Ventilation Systems

Constant and Variable Air Volume Systems

Air Handling Units

Energy Savings OpportunitiesEnergy Recovery Devices

Air Flow Rate Variation

Case Study


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Ventilation

Single flow ventilationOne flow (either extraction orblowing) is forced mechanically

with fans into the building

Extracted Air

Make up

Air

Make up

Air

Double flow ventilationExtracted and make up air areforced mechanically with fans

Extracted Air

Make up Air


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Ventilation

Constant Air Volume Systems (CAV)(Example of a single flow system)

Variable Air Volume Systems (VAV)(Example of double flow system)

Make up

Air

Make

up Air

Supplied

air

Recycled

air

Extracted

Air

A way to reduce consumption by adjusting theflow rate to occupancies and needs

Designed for the most critical configuration, ieHigh fan consumption all the time


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Air Handling Units : Main Components

Air Handling Unit (Example for a single flow ventilation system) 1 : Mixing box

2 : Filter

3 : Hot Heat exchanger (Pre-Heating)

4 : Cool Heat exchanger 5 : Hot Heat exchanger (Re-Heating)

6 : Humidifier

7 : Fan

Recycled Air

Make up Air

Supply air

blown into the

building


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Air Handling Unit (Example for a double flow ventilation system) 1 : Economizing Mixing box

Air Handling Units : Main Components

Recycled

Air

Makeup Air

Supply air

blown into thebuilding

Extracted

Air

Air extracted

from the

building

1


7/14Schneider Electric 7- Division - Name Date

Agenda

Introduction to VentilationSingle and Double Flow Ventilation Systems

Constant and Variable Air Volume Systems

Air Handling Units

Energy Savings OpportunitiesEnergy Recovery Devices


Case Study



Energy Recovery

Principle

Without Energy Recovery With Energy Recovery



Energy Recovery

Different types of system

2 Heat Exchanger Systems

Tube in Shell Exchanger

Supply air

blown into the

building

Make

up Air

Extracted

Air

Air extracted

from the

building

Extracted

Air

Make

up Air

Supply air

blown into the

building

Air extracted

from the

building



Energy RecoveryDifferent types of system

Heat Pipes

Rotary Exchanger

Condens

ation

Ev

aporation

Air extracted from

the building

Make up

Air

Vapor

Liquid

Motor

Purge Zone

Belt

Air extracted

from the building

Purge

Zone


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Energy Recovery

Different types of systemRecycle extracted air

Extracted

Air

Make

up Air

Motorized

dampers


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Principle :The air flow rate varies between the minimum required for health of

occupants and the maximum that can be deliver in order to reach the most

critical conditions

=> Minimum Fan and Heating/Cooling Consumption

Interest compared to a constant flow rate :

Air transportation in Constant flow system often counts for20 to 40% of theinstallation operating costs.

Appropriated for the use of Free Energies :

=> In Summer : Use fresh outside air for free-cooling

How :Dampers / Valves

Bypass

Pre-rotating blades / Variable Pitch

VSD



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Example :

Air Flow Rate Variation and Regulation

Extracted

Air

Make up

Air

Motorized

dampers

Make up Air

settings

Settings

Hot

valvesopening

Ambient

temperature

Minimum

Make-up air

flow rate

P

Difference in Pressure

Controller

P


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Case Study :

One Schneider plant in PolandDouble Flow Ventilation System on one workshop

Heating perform with :Hot water exchangers in the AHU

Radiators

Running all the time 49 weeks/year

Electricity price : 0.49 PLN/kWh ( 1 = 4.45 PLN)

Air Supply side :

Fan motor : P=22 kW, =89 During the week : 2*8 full occupation

1*8, 70% occupation rate Week-end : no activity VSD could be implemented

Documents

125963076 9 Training HVAC Ventilation