Mechanical Drawing Symbols

The vector stencil library "HVAC controls" contains contains 24 HVAC control symbols: sensors, actuators, timers, controllers, I/ O points.
Use it for drawing HVAC system diagrams, heating, ventilation, air conditioning, refrigeration, automated building control, and environmental control design floor
plans and equipment layouts.
"HVAC (... Heating, Ventilation and Air Conditioning) is a control system that applies regulation to a heating and/ or air conditioning system. ...
Central controllers and most terminal unit controllers are programmable, meaning the direct digital control program code may be customized for the intended use. The program features include time schedules, setpoints, controllers, logic, timers, trend logs, and alarms. The unit controllers typically have analog and digital inputs that allow measurement of the variable (temperature, humidity, or pressure) and analog and digital outputs for control of the transport medium (hot/ cold water and/ or steam). Digital inputs are typically (dry) contacts from a control device, and analog inputs are typically a voltage or current measurement from a variable (temperature, humidity, velocity, or pressure) sensing device. Digital outputs are typically relay contacts used to start and stop equipment, and analog outputs are typically voltage or current signals to control the movement of the medium (air/ water/ steam) control devices such as valves, dampers, and motors." [HVAC control system. Wikipedia]
The vector stencils example "Design elements - HVAC controls" is included in HVAC Plans solution from the Building Plans area of ConceptDraw Solution
Park.