Test Adjust Balance (TAB) is the systematic process of measuring, adjusting, and verifying HVAC system airflow, temperature distribution, and equipment performance to match design specifications. TAB procedures ensure proper air delivery to all occupied spaces while optimizing equipment efficiency. Professional TAB services are essential for complex commercial systems to achieve design performance.
Technical Details
TAB technicians measure supply and return air velocity using calibrated anemometers and balancing hoods, calculate actual airflow in cubic feet per minute (CFM), and compare against design documents. They adjust dampers in ductwork and equipment to redirect airflow, verify temperature differentials at supply registers, and confirm thermostat performance. Measurements are recorded in a detailed TAB report documenting baseline conditions and adjustments.
Practical Significance
Proper balancing prevents hot and cold spots, reduces occupant complaints, and improves equipment efficiency by 5-15 percent. Unbalanced systems create excessive airflow in some zones while starving others, reducing comfort and increasing equipment wear. TAB services typically cost 2-5 percent of system installation price but prevent costly future adjustments.