Testing, adjusting, balancing (TAB) are the three major steps used on the job to achieve proper operation of heating, ventilating, and air conditioning

Air conditioning

An air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle...

 (HVAC

HVAC

HVAC refers to technology of indoor or automotive environmental comfort. HVAC system design is a major subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer...

) systems. These systems are also called "environmental systems".

Testing

Testing is the use of specialized and calibrated instruments to measure temperatures, pressures, rotational speeds, electrical characteristics, velocities and air and water quantities for an evaluation of equipment and system performance.

Adjusting

Adjusting is the final setting of balancing devices such as dampers and valves, adjusting fan speeds and pump impeller sizes, in addition to automatic control

Automatic control

Automatic control is the application of concepts derived from the research area of modern control theory. Automatic control is also a technology for application of control strategies. The implementing requires prior of analyzing and modeling of the subject to be controlled...

devices such as thermostats and pressure controllers to achieve maximum specified system performance and efficiency during normal operation.

Balancing

Balancing is the methodical regulation of system fluid flows (air or water) through the use of acceptable procedures to achieve the desired or specified airflow or water flow.

Balancing will be applied to both air side and water side. Balancing of air side is known as air balancing and water side is known as water (hydronic) balancing.