Outlined below are the most commonly used hvac control symbols and their meanings.
Click here to view easy-to-use compiled charts of these symbols.
pressure sensor
Measures pressure of gases or liquids.
VARIABLE SPEED DRIVE
VSD enables variable control of motor speed and torque so that hvac systems can run at optimum efficiency.
Flow switch
Flow switches trip pumps on or off to control fluid flow.
Air conditioning controller
An electronic module that controls the hvac system.
carbon monoxide sensor
Sensors used to measure and thereby limit carbon monoxide.
co2 sensor
Used to measure CO2 concentration in air and adjust ventilation system accordingly.
DIFFERENTIAL PRESSURE TRANSDUCER
DPTs measure pressure difference across a region and aid in hvac zones systems such as stairwell pressurization, lift pressurization ,etc.
BUILDING MANAGEMENT SYSTEM
BMS is a computer based system that monitors the equipment systems of a building.
Relative Humidity sensor
Measures relative humidity of air.
Velocity meter
Measures air velocity in ducts.
FLOW METER
Measures flow in ducts and pipes.
Top to bottom
side to side
side to bottom
Damper
Dampers are used to regulate airflow.
VAV Box
VAV boxes regulate air flow through a duct.
THERMAL Energy Meter
Thermal Energy Meters measure amount of energy content in chilled water liquid flow.
Heat Exchanger
Heat exchanger is a device that transfers thermal energy from one medium to another.