IDEF3 Standard

"HVAC (stands for Heating, Ventilation and Air Conditioning) is a control system that applies regulation to a heating and/ or air conditioning system. Usually a sensing device is used to compare the actual state (e.g., temperature) with a target state. Then the control system draws a conclusion what action has to be taken (e.g., start the blower).
More complex HVAC systems can interface to Building Automation System (BAS) to allow the building owners to have more control over the heating or cooling units. The building owner can monitor the system and respond to alarms generated by the system from local or remote locations." [HVAC control system. Wikipedia]
The vector stencils library "HVAC control equipment" contains 48 symbols of heating, ventilation, air conditioning, refrigeration and automated building control equipment.
Use the design elements library HVAC control equipment to draw HVAC plans, schematic diagrams of heating, ventilation, air conditioning, refrigeration and automated building control systems, environmental control design building plans and equipment layouts using the ConceptDraw PRO diagramming and vector drawing software.
The shapes library HVAC control equipment is contained in the HVAC Plans solution from the Building Plans area of ConceptDraw Solution Park.