HVAC - Main parts in order

Different parts of typical AHU

*Mostly all the information presented here are from The Engineering Mindset Youtube Channel.

Supply air, main parts (excluding sensors)

1. Grille
2. Damper
3. Frost protection coil (usually electric coil/heater)
4. Pre-Filter
5. Filter
6. Cooling coil
7. Heating coil
8. Humidifier (steam or water mist)
9. Supply fan (centrifugal or EC type)

Main sensors :

1. Pressure sensor (Magnelic)
• Measure pressure before and after the pre-filter and filter
2. Temperature sensor (Thermistor)
• Measure temperature before and after coils to adjust heating and cooling load
3. Humidity sensor
• Measure humidity to adjust humidifier load
4. Static pressure sensor
• Measure static pressure to adjust centrifugal fan speed (when VAD are installed)

1. Grille

Grille prevent animals and waste to enter inside the AHU.

2. Damper