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HVAC SystemAHU Control & Troubleshooting

Eng. Ahmed Hussein

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Introduction to HVAC Systems

Objective Comfort Zone

Temperature 22 °C 26 °C

Relative Humidity 40 % R.H 60 % R.H

Comfort Zone 24 °C & 50 % R.H HVAC Systems, AHU Control &

Troubles1hooting

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Indoor Air Quality (IAQ)

HVAC Systems, AHU Control & Troubles1hooting

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HVAC System ComponentsWhere’s the fresh air duct ?!?!!

HVAC Systems, AHU Control & Troubles1hooting

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1.Chiller

HVAC System Components

HVAC Systems, AHU Control & Troubles1hooting

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HVAC System Components2. Cooling Tower

HVAC Systems, AHU Control & Troubles1hooting

Chiller Refrigerant Cycle

Condenser

Compressor

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HVAC System Components3. Boiler

HVAC Systems, AHU Control & Troubles1hooting

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HVAC System Components4. Air Handling Unit (AHU)

HVAC Systems, AHU Control & Troubles1hooting

Supply Duct Fan Vibration Connection

Cooling Coil

Filter Sectio

n

Return Duct

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HVAC System Components5. VAV (Variable Air Volume)

HVAC Systems, AHU Control & Troubles1hooting

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HVAC System Components6. Ductworks & Air Terminals

HVAC Systems, AHU Control & Troubles1hooting

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AHU Control & Troubleshooting

Control Concept 1. Sensor 2. Controller Device (Brain)3. Actuator

HVAC Systems, AHU Control & Troubles1hooting

Sensor

Controller

Actuator

Input

Output

Set Point (Value)

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AHU Control & Troubleshooting

HVAC Systems, AHU Control & Troubles1hooting

Sensor

Controller

Actuator

Input

Output

1- Thermostat2- Pressure Gauge3- R.H % Sensor4- DPS5- Flow Switch

BMSDDCMCC

1- Motorized Damper2- Two-way Valve3- Three-way Valve4- VSD

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AHU Control

HVAC Systems, AHU Control & Troubles1hooting

Exhaust Air

Supply Air

Return Air

Return Fan

Supply Fan

EH

M

M

M

M

MCC DDC

AO

T

TDPS

DPS

AO

AO

AODO

DI

AI

AI

AI

AI

AO