A new building has never been tested. Everything about it, from duct leakage to damper settings, is as it came out of construction. Air balancing is how the owner finds out whether the systems deliver what the design promised, before the building is occupied.
What balancing verifies in a new building
- Total airflow at each air handler matches design.
- Each outlet receives its design airflow.
- Outdoor air meets the ventilation requirement.
- Exhaust fans move the design airflow.
- Fan speeds, motor loads and static pressures are within expected ranges.
- Controls respond as the sequence says.
How it differs from balancing an existing building
| New construction | Existing building | |
|---|---|---|
| Starting point | System never tested | System has history and drift |
| Main risk | Incomplete systems, construction dust, late changes | Altered layouts, wear and neglected maintenance |
| Access | Easy before ceilings close | Often limited by finishes |
| Deadline | Occupancy and final inspection | Complaints or renovation |
The sequence
- Systems installed, started up and running with final filters.
- Controls working and addressed.
- Ceilings and diffusers in, with dampers and test ports accessible.
- Balancer measures, adjusts and records.
- Deficiencies reported, fixed and rechecked.
- Report issued and filed before occupancy.
The checklist for what must be ready is in our pre-test checklist, and this guide covers preparing the systems.
Why occupancy depends on it
Many jurisdictions require a TAB report before issuing a certificate of occupancy for commercial buildings. A report that is late or incomplete can hold up the certificate and the owner’s move-in date. See why TAB matters for occupancy approval.
Common mistakes
- Balancing before the building is ready. Tests on incomplete systems have to be repeated.
- Ignoring late design changes. The airflow targets move with the layout.
- Booking the balancer last. A fixed turnover date without a booked balancer is a risk.
Questions owners ask about balancing a new building
When should the balancer be booked?
As soon as the turnover date is known. Early booking protects the date and lets the balancer plan access. See how to coordinate TAB with the schedule.
How long does it take?
It depends on system size. A single rooftop unit with 10 to 15 registers typically takes about half a day, and larger projects can take 1 to 3 days.
What does the owner get?
A report with measured and design airflow for each outlet, fan data, static pressures, outdoor air and any deficiencies, which is also a baseline for future maintenance.
What a pre-balance walk should find
Before the balancer starts, walk the building with the mechanical contractor. Look for missing balancing dampers, closed fire dampers, filters not installed, ceilings still open over outlets and fans not running. Anything on that list is cheaper to fix before the balancer arrives than during the test.
Related reading: Top HVAC Installation Challenges Faced by General Contractors and How to Manage Multi-Zone Systems in Large HVAC Projects.
To book balancing before occupancy, call Ghazi Hussain at (908) 323-9780 for a quote.
