HVAC Testing, Adjusting and Balancing (TAB)

Testing, adjusting and balancing (TAB) is the process of measuring every airflow and water flow in an HVAC system and adjusting dampers, valves and fan or pump speeds until each room, coil and terminal gets its design quantity. TABCOMM delivers certified TAB to NEBB and AABC procedures

Testing, Adjusting and Balancing

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A Well Designed System Still Needs Balancing

Air and water always take the easiest path. Without balancing, rooms near the AHU are cold, rooms at the end are warm, and pumps and fans run harder than they need to. Balancing puts the right quantity in the right place, and gives you a certified record of it.

TAB Scope

Air systems	Water systems
AHU and FAHU airflow, fan RPM, motor current, filter and coil pressure drop, external static pressure	Chilled water pump flow, head, motor current and VFD operation
FCU airflow, supply temperature and sound levels	Main, branch and terminal balancing
VAV and CAV minimum and maximum airflow calibration	PICV and balancing valve verification
Supply, return and outside air verification	Chiller evaporator and condenser water flows
Toilet and kitchen exhaust balancing	Heat exchanger flow balancing
Stair pressurisation and smoke extraction	AHU and FCU coil water flows
Car park ventilation	Differential pressure verification

How We Deliver TAB

Engineering review. Design criteria, equipment schedules and shop drawings reviewed.
Pre-TAB inspection. Ductwork and pipework complete, filters in, dampers and valves accessible, electrical supply ready.
Air balancing. Totals measured at the AHU, then branches and terminals adjusted with capture hoods, pitot traverses and anemometers.
Water balancing. Pumps verified first, then main, branch and terminal valves set with differential pressure and ultrasonic flow meters.
Performance verification. Final readings taken and compared with design tolerances.
Certified report. Full TAB report with schematics, readings and instrument calibration certificates.

Calibrated Instruments We Use

Capture hoods, pitot tubes and digital manometers, anemometers, differential pressure meters, ultrasonic flow meters, tachometers, clamp meters, temperature and humidity meters, and sound and vibration meters. Every instrument carries a current calibration certificate, included with the report.

Standards We Follow

NEBB Procedural Standards for TAB, AABC National Standards for Total System Balance, ASHRAE Handbook (HVAC Applications), SMACNA and CIBSE.

What You Receive

Certified TAB report with executive summary · Airflow and water flow readings for every terminal and system · System schematic drawings · Deficiency reports · Instrument calibration certificates

Recent TAB Projects

OXAGON, NEOM · Seven Entertainment Complex, Riyadh · Rua Al Madinah, Dar Al Hijrah, Madinah · King Abdulaziz International Airport, Jeddah · King Salman Specialist Hospital, Hail · Misk Schools New Campus, Riyadh

TAB FAQ

Do you have any question?

1. What does TAB stand for in HVAC?

TAB stands for Testing, Adjusting and Balancing. It is the process of measuring and adjusting HVAC air and water flows so each part of the system delivers its design quantity.

2. What is the acceptable tolerance in air balancing?

Most specifications require terminal airflows within plus or minus 10 percent of design, and some critical spaces require plus or minus 5 percent. We work to the tolerance in your project specification.

3. When should TAB be done?

After the HVAC installation is complete, ducts and pipes are clean and sealed, and the system can run in normal mode. Balancing before that point usually has to be repeated.

4. Is TABCOMM’s TAB work certified?

Our TAB is carried out to NEBB and AABC procedures by NEBB certified TAB technicians, and our reports are accepted by major consultants across Saudi Arabia.