top of page


TnC is a NEBB (National Environmental Balancing Bureau) Certified TAB Firm which is  working on many international projects for Testing, Adjusting and Balancing works. TnC has all TAB equipments that NEBB requires. All equipments are kept as calibrated. 
Testing Adjusting Balancing works are being continued in Europe, Middle East and United States according to NEBB Requirements.
HVAC Testing, Adjusting and Balancing (TAB) are the three major steps used to achieve proper operation of HVAC (heating, ventilation, and air conditioning) systems. TAB usually refers to commercial building construction and the specialized contractors who employ personnel that perform this service.
In general, the TAB specialist performs air and hydronic measurements on the HVAC systems and adjusts the flows as required to achieve optimum performance of the building environmental equipment. The balancing is usually based upon the design flow values required by the Mechanical Engineer for the project, and the TAB contractor submits a written report which summarizes the testing and balancing and notes any deficiencies found during the TAB work.


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 is the final setting of balancing devices such as dampers and valves, adjusting fan speeds and pump impeller sizes, in addition to automatic control devices such as thermostats and pressure controllers to achieve maximum specified system performance and efficiency during normal operation.



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.

Pre-planning for TAB work includes making certain that all the necessary parties and individuals to conduct the work are onboard. The type of building and systems to be tested and a realistic evaluation of what skills the TAB technician possesses are key planning elements.


  • Often, a controls specialist will be needed to operate the system for the TAB technician.

  • The representatives from the original equipment suppliers may be needed as a resource, at a minimum, but for complex equipment and systems or in a new building startup a manufacturer's representative may be required at the site to operate the mechanical equipment.

  • If the building has a facilities manager that individual is typically the most important participant with which the on-site TAB technicians will work. Facility managers have a substantial vested interest in ongoing customer satisfaction—the people who work or live in the building are actual end-use customers—and their satisfaction will ultimately be the key measure of success.


Occasionally, a system cannot be balanced or made to perform in accordance with the contract's design specifications regardless of the number of balancing dampers or valves that can be installed. Competent TAB technicians should be prepared for this possibility and work with the appropriate individuals to formulate recommendations as part of the final TAB report.


It should be made clear that the TAB work is not "commissioning." Most commissioning services are completed by firms having technicians experienced with each of the individual building systems—HVAC, lighting, plumbing, electrical, and security systems.


We provide the following TAB services:


•  Air and hydronic environmental balancing


•  HVAC systems survey (operational check-outs,   calibration requirements, relocations)


•  Design and balance existing air distribution systems


•  Water (Hydronic) Balance


•  Performance Tests for HVAC Equipment


•  Room/space pressure relationship testing


•  Room Pressure Testing


•  Duct Pressurization Testing


•  Duct Leakage Testing


•  Design Review of HVAC Systems


•  Inspection of HVAC System


•  Troubleshooting of HVAC Systems


•  Consulting Services for HVAC Systems


•  Control System Verification


•  Chiller and Cooling Tower Performance Testing


•  Central Plant Performance Testing


•  Pre-Construction Document Review


•  Fume Hood Testing / Kitchen Exhaust Hood Testing


•  Existing Conditions Documentation "As Built"


•  Stairwell Pressurization


•  Smoke Management Systems Testing


•  Underfloor Plenum Testing


•  Ultra Sound Measurements

bottom of page