Each mechanical engineering office uses their own set of HVAC plan symbols; however, the symbols below are fairly common across many offices. Refer to the symbol legend sheet for special symbols used in a particular set. You may also be interested in reviewing HVAC abbreviations that are typically used in drawings.
Supply and Return Airflow Symbols
Standard 4-Way Blow Diffuser
3-Way Blow Diffuser
2-Way Blow Diffuser
1-Way Blow Diffuser
Return Grille
Direction of Supply Air
Direction of Return Air
Door Undercut Size
Door Louver with Clear Area
HVAC Damper Symbols
Volume Damper
Fire Damper
Smoke Damper
Combination Smoke and Fire Damper
Back-draft Damper
HVAC Piping Symbols
Chilled Water Supply
Chilled Water Return
Hot Water Supply
Hot Water Return
Vent Pipe
Drain Pipe
Make-Up Water Pipe
HVAC Sensor Symbols
Thermostat
Humidity Sensor
