📋 HVAC Symbols & Notes
- □ with X: Supply diffuser
- ○ with arrow: Return grille
- ΔT: Temperature difference
- CFM: Cubic Feet per Minute (airflow)
- VAV: Variable Air Volume box
Test: On mechanical plans, a square with an “X” typically means?
❄️ M-Plan Mechanical (HVAC) Cheat Sheet
Learn to read HVAC symbols, ductwork, airflows, schedules, and equipment callouts.
🌬️ Airflow & Ductwork
- Main ducts bold, branches lighter
- Arrows show airflow direction
- Duct sizes labeled (e.g., 18″×12″)
Test: What does “2000 CFM” represent?
⚙️ Equipment Tags
- AHU-1: Air Handling Unit #1
- RTU-2: Rooftop Unit #2
- EF-3: Exhaust Fan #3
- FCU-4: Fan Coil Unit #4
Test: “RTU-2” on a plan stands for?
📑 Mechanical Schedules
Mechanical schedules list equipment data:
- AHU-1: 5000 CFM, 10 tons cooling
- RTU-2: Gas heat, 7.5 tons cooling
- EF-3: 1500 CFM exhaust
Test: Where do you find airflow, tonnage, and voltage for AHU-1?
🎛️ Thermostats & Controls
- Thermostats marked with “T” or control symbol
- Zoning = separate thermostats for areas
- Controls tied to AHU/RTU operation
Test: What does a “T” symbol in a room usually mean?
📐 Sections & Details
- Duct transitions shown in enlarged sections
- Mechanical rooms detailed with equipment pads
- Roof penetrations & curbs detailed in M-sheets
Test: A bubble “5/M2.1” refers to?