HVAC Test and Balance Report: What Facility Leaders Should Verify

The renovation appears complete. New terminal units are operating, the controls contractor has finished programming, and the HVAC test and balance report has arrived with hundreds of readings marked near design. Project closeout is scheduled for the end of the week.

Then someone notices that several remote outlets remain below their required airflow. One air-handling unit was tested in manual mode, and multiple deficiencies listed near the back of the report have not been resolved.

The document is complete, but the system may not be.

An HVAC test and balance report should never be accepted simply because every schedule contains final numbers. The report must show what was tested, how the equipment was operating, what adjustments were completed, and which conditions prevented the system from reaching its intended performance.

An HVAC test and balance report documents measured airflow, water flow, pressure, temperature, equipment operation, balancing adjustments, and unresolved deficiencies. Facility leaders use it to verify whether an HVAC system performs within the defined project requirements.

The value of the report is not its page count. It is the clarity it provides before project acceptance.

Key Takeaway

• Confirm that the testing scope matches the project and affected systems.
• Verify that equipment and controls were ready and operating normally.
• Review total equipment performance before judging individual outlet or coil readings.
• Compare initial and final values to understand what balancing changed.
• Read every deficiency note and determine whether corrective work or retesting is required.
• Do not apply one acceptance percentage blindly to every reading.

What Is Included in an HVAC Test and Balance Report?

An HVAC test and balance report, commonly called a TAB report, records field measurements from the building’s air and hydronic systems.

Depending on the project, it may include the following:

• Air-handling-unit and fan airflow
• Supply, return, exhaust, and outdoor-air quantities
• Branch, terminal-unit, diffuser, and grille readings
• Fan speed, static pressure, and operating data
• Pump flow and differential pressure
• Water flow through coils and equipment
• Damper and valve positions
• Temperature measurements
• Initial readings and final readings
• Completed adjustments
• Deficiencies that prevented full system performance

A useful report connects central equipment performance with what reaches the occupied spaces.

An outlet schedule alone cannot explain whether the air handler produced enough airflow, whether the branch had adequate pressure, or whether a terminal unit responded correctly. In the same way, a coil-flow reading has limited value without information about pump operation, differential pressure, valve position, and total system flow.

Facility leaders should be able to follow the system from the equipment to the final zone.

Review the Report Through Five Main Questions

A detailed TAB document becomes easier to evaluate when the review is organized around five practical questions:

1. Was the correct scope tested?
2. Was the system ready and operating normally?
3. Do equipment totals support the branch and terminal readings?
4. What deficiencies prevented full performance?
5. Is corrective work or retesting required before acceptance?

These questions move the review beyond percentages and toward an informed project decision.

1. Was the Correct Scope Tested?

Start with the project scope before reviewing individual measurements.

A TAB contractor may complete every item included in the contract while important connected systems remain outside the assigned work. That distinction matters during renovations, tenant improvements, equipment replacements, and partial-floor projects.

Confirm whether the report covers:

• The full building or only the renovated area
• New and existing equipment affected by the work
• Air systems, hydronic systems, or both
• Outdoor-air and exhaust quantities
• Building or room pressure relationships
• Existing branches connected to new terminal equipment
• Adjacent spaces that may have been affected
• Normal occupied schedules and operating modes

Consider a tenant renovation that adds several terminal units to an existing duct branch. Measuring only the new diffusers may confirm airflow within the renovated suite, but it may not show whether adjacent spaces lost air after the branch was modified.

The same concern applies to hydronic systems. A new coil can meet its required flow while another coil on the same loop becomes under-supplied.

A complete report should match the actual impact of the project, not just the boundaries of the construction area.

2. Was the System Ready for Testing?

TAB results are only as reliable as the operating condition of the system during testing.

Meaningful final verification is difficult when filters are heavily loaded, belts are slipping, control sequences are incomplete, dampers are inaccessible, or valves fail to respond. A technician can record readings under those conditions, but the results may not represent normal building operation.

Look closely for notes involving:

• Equipment placed in manual operation
• Incomplete controls programming
• Failed actuators or valves
• Dirty filters, coils, or strainers
• Closed fire or smoke dampers
• Duct leakage or disconnected ductwork
• Incorrect fan rotation
• Missing access panels or test ports
• Pumps or fans operating outside the intended range
• Equipment that was unavailable during testing

Testing in manual mode may be necessary during the adjustment process. The concern is whether final readings were verified after the equipment returned to normal automatic operation.

A fan can deliver the required airflow when manually forced to a fixed speed and still fail to maintain that airflow when the control sequence is restored. The same applies to pumps, dampers, terminal units, and control valves.

The final report should clearly distinguish temporary test conditions from verified operating conditions.

3. Do Equipment Totals Support the Distribution Readings?

Review the major equipment before studying individual outlets or coils.

For air systems, begin with the air handler, rooftop unit, supply fan, return fan, or exhaust fan. For hydronic systems, start with the pump, chiller, boiler, and primary distribution loop.

The first questions should be straightforward:

• Is the equipment producing the intended total airflow or water flow?
• Is it operating at a reasonable fan speed, pump speed, pressure, and control position?
• Are supply, return, exhaust, and outdoor-air quantities coordinated?
• Is system operation stable during testing?
• Do branch totals reasonably align with equipment totals?

If an air-handling unit delivers only part of its intended airflow, low diffuser readings throughout the building may reflect an equipment or upstream condition rather than incorrect outlet settings.

If total pump flow is correct but several remote coils remain low, the central plant may have adequate capacity while water distribution remains uneven.

This distinction is especially important before recommending major equipment work. As explained in the guide to commercial HVAC balancing before replacement, new equipment can inherit the same unresolved duct, piping, control, and distribution problems.

A strong TAB report helps the owner determine whether the issue begins at the equipment, within the distribution system, or at the terminal device.

Compare Design Values With Actual Measurements

TAB schedules typically show a design value, an initial measured value, and a final measured value.

The design value comes from the project documents, equipment schedule, approved submittal, or another established requirement. The measured value shows what the system delivered during field testing.

The percentage difference is useful, but it does not explain the cause.

A diffuser at 85 percent of design could be affected by a local damper, a low-performing terminal unit, inadequate branch pressure, or an air handler that is short on total airflow.

A coil below its required flow might be limited by a balancing valve, control valve, restricted strainer, inadequate differential pressure, or pump operation.

Readings should therefore be reviewed as part of a connected system rather than as isolated pass-or-fail numbers.

Do Not Apply One Acceptance Percentage to Every Reading

There is no single acceptance percentage that should be applied blindly to every TAB value.

Required tolerances depend on the project specification, system type, device, measurement method, design intent, and applicable owner or agency requirements.

A small difference at one office diffuser may have limited operational impact. The same percentage difference in outdoor air, laboratory exhaust, critical-room pressure, or a remote hydronic circuit may be far more significant.

The report should identify the acceptance criteria used for the project. When it does not, facility leaders should ask the project team to confirm the governing specification or requirement.

The important question is not whether every number looks close to 100 percent. It is whether the system meets the performance criteria established for that project.

Initial and Final Readings Tell the Real Story

A final number shows where the system ended. The initial reading shows where it began.

That difference can reveal how much adjustment was required and whether the final condition was achieved through reasonable operating settings.

For example, a diffuser may finish close to design only after an upstream damper is nearly closed. A remote branch may reach its required flow only after fan speed is increased substantially. A coil may meet its target after a balancing valve on a nearby branch is heavily restricted.

Those results may be acceptable, but they deserve context.

Initial-to-final comparisons help facility leaders understand:

• How far the system was from the intended condition
• Which areas required the largest corrections
• Whether adjustments changed total equipment performance
• Whether one improvement reduced flow elsewhere
• Whether final settings are practical and repeatable
• Whether the system has limited remaining adjustment capacity

This information becomes valuable during future troubleshooting, renovation planning, and equipment replacement.

Review Airflow as a Pattern, Not a Collection of Outlets

When evaluating air systems, look for recurring patterns.

One low diffuser may point to a local restriction, damaged flex duct, closed damper, or incorrect outlet setting. If every diffuser served by the same terminal unit is low, the problem likely sits farther upstream.

Several remote terminal units below design may indicate insufficient branch pressure, an incorrect fan setpoint, duct leakage, or a control sequence that limits available airflow.

Patterns worth investigating include:

• One branch consistently below design
• Remote outlets lower than nearby outlets
• Multiple terminal units at maximum command
• Supply airflow that does not coordinate with return or exhaust
• Outdoor airflow below the project requirement
• Similar spaces with significantly different delivery
• Final readings that change when other zones open or close

The guide to commercial HVAC airflow problems explains why local, zonal, and system-wide issues require different levels of investigation.

A TAB report should help identify which level of the system requires attention.

Review Hydronic Results as a Distribution System

Hydronic schedules should show how water is distributed through pumps, risers, branches, coils, and critical terminal equipment.

A correct total pump flow does not prove that each coil receives the required quantity.

Remote branches may remain under-supplied while nearby circuits receive more flow than needed. Control valves may stay fully open because insufficient differential pressure is available at the coil. Balancing valves may be placed at extreme positions to compensate for another system condition.

Facility leaders should review:

• Total pump flow
• Branch and riser flow
• Critical coil flow
• Pump speed and differential pressure
• Control-valve position
• Balancing-valve setting
• Chilled-water supply and return temperatures
• Notes about missing test points or inaccessible devices

Hydronic results should explain where the water is going, not simply confirm that the pump is running.

When a system has changed through years of renovations, control updates, and field adjustments, earlier balance conditions may no longer represent current operation. The article on why HVAC systems fall out of balance provides additional context for reviewing older systems and outdated reports.

4. What Deficiencies Prevented Full Performance?

The deficiency section may contain the most important information in the entire report.

A final schedule can appear acceptable while unresolved issues remain buried in notes, comments, or exception pages.

Common deficiencies include:

• A fan unable to produce the required airflow
• A pump unable to provide the required flow or pressure
• A failed terminal-unit actuator
• An inaccessible damper or valve
• An incorrectly sized control device
• A restricted coil, strainer, duct, or piping branch
• Missing test ports
• An unstable control sequence
• A system tested before construction was complete
• Design values that do not match installed equipment
• Equipment unable to operate simultaneously under the required condition

Each deficiency should lead to a decision.

Who is responsible for correcting it? Does it affect project acceptance? Is the condition a repair issue, a controls issue, an installation problem, a design question, or a system-capacity limitation? Must the affected system be retested afterward?

A deficiency without an assigned next step can easily remain unresolved after project closeout.

Separate Balancing Issues From Other Problems

Not every condition found during TAB can be corrected by adjusting a damper or valve.

The findings generally fall into five categories.

Adjustment

The system is capable of meeting the requirement, and performance can be corrected through damper, valve, fan, pump, or related control adjustments.

Repair

A failed actuator, damaged valve, disconnected duct, restricted coil, or malfunctioning component must be repaired before reliable final measurements can be completed.

Controls Correction

The equipment is physically capable, but sequences, setpoints, sensors, or device commands prevent the system from operating correctly.

System Modification

The installed ductwork, piping, terminal equipment, valves, or other components require physical changes.

Engineering Review

The system cannot meet the specified condition, installed equipment differs from the design, or current building use no longer matches the original assumptions.

A premium TAB report should make these distinctions clear rather than presenting every problem as a balancing adjustment.

Verify Outdoor Air, Exhaust, and Pressure Relationships

Comfort readings are only one part of HVAC performance.

Where included in the scope, review outdoor airflow, exhaust quantities, and pressure relationships as connected conditions.

An air handler may deliver the correct total supply airflow while outdoor air remains below the intended requirement. A restroom exhaust fan may meet its individual airflow target while creating excessive negative pressure because replacement air was not considered.

Building and room pressure conditions can affect:

• Exterior-door operation
• Lobby drafts
• Outdoor-air infiltration
• Odor movement
• Critical-room containment
• Temperature control near entrances
• Interaction between new and existing exhaust systems

The readings should show how the systems work together, not just whether each fan operates independently.

Confirm That Controls Maintain the Final Balance

TAB and controls work closely together, but they are not interchangeable.

The balancing process may require manual commands to place dampers, valves, fans, and pumps in specific positions. Final performance, however, should reflect normal automatic operation whenever practical.

Before acceptance, confirm whether:

• Control devices responded correctly
• Minimum and maximum airflow settings were verified
• Fans and pumps maintained the required operating conditions
• Systems were returned to automatic mode
• Final readings remained stable after automatic control resumed
• Any temporary overrides were removed
• Remaining controls deficiencies were documented

A system that balances only under manual commands is not fully verified for normal operation.

5. Is Retesting Required Before Acceptance?

Some deficiencies can be corrected without materially changing other readings. Others affect the entire system and require additional verification.

Retesting may be appropriate after:

• Fan or pump repair
• Controls programming changes
• Actuator or valve replacement
• Duct or piping modification
• Coil or strainer cleaning
• Equipment replacement
• Outdoor-air or exhaust adjustment
• Correction of missing or inaccurate design information

The final report should identify whether retesting is required and which measurements must be repeated.

Project closeout should not rely on an outdated set of readings collected before significant corrective work was completed.

Questions to Ask Before Approving the TAB Report

Before accepting the document, confirm:

• Does the report match the contracted project scope?
• Were affected existing systems included?
• Were equipment and controls ready for final testing?
• Are design, initial, and final values clearly shown?
• Do equipment totals support the branch and terminal readings?
• Are the project acceptance criteria identified?
• Are unresolved deficiencies easy to find?
• Has responsibility been assigned for corrective work?
• Is retesting required after repairs or control changes?
• Does the final report represent normal automatic operation?
• Can the document serve as a reliable baseline for future facility work?

The goal is not to dispute every measurement. It is to confirm that the report supports an informed acceptance decision.

How FSE Supports HVAC Performance Verification

FSE reviews test and balance results in the context of equipment operation, airflow and water-flow distribution, control response, and unresolved field conditions.

The goal is not simply to complete a schedule of readings. It is to document whether the connected system performs within the defined project requirements and identify what prevents full operation when it does not.

Through FSE’s Test and Balance Services, facility teams can establish existing conditions, verify renovation and equipment projects, identify deficiencies requiring corrective action, and create a dependable baseline for future operational decisions.

Clear documentation helps owners separate balancing adjustments from repairs, controls corrections, system modifications, and conditions requiring further technical review.

A TAB Report Should Support a Decision

An HVAC test and balance report should do more than show completed readings.

It should explain whether the system was ready for testing, how actual performance compares with project requirements, what adjustments were made, and which deficiencies remain unresolved.

Before accepting the report, review the scope, equipment totals, distribution patterns, control conditions, and deficiency notes. Confirm whether corrective work has been completed and whether final retesting is still required.

The most valuable TAB report is not the one with the cleanest percentages.

It is the one that gives facility leaders an accurate record of how the HVAC system performs—and a clear understanding of what still needs attention.