An air balance report proves that the air the design called for is arriving in each room. It records, per register, the design airflow, the airflow measured, and the airflow after the dampers were adjusted, and it records, per system, the total airflow, the static pressures and the fan data that explain the totals. For commercial work it is often a contract deliverable; for residential work it is the document that ends a comfort complaint with evidence rather than another visit. This page is for the technician or owner in a US HVAC contracting business building the air balance report template, and it sets out what any air balancing report sheet has to carry before it is worth downloading or printing.
The header and the system data
Project, site, system tag, date, technician and instruments used with their calibration date. Equipment make, model and serial. Fan data: design and measured RPM, motor amperage and voltage, drive and sheave sizes where adjustable. Filter type and condition. Total external static pressure, and the static across the coil and the filter separately. These are what explain the register readings when they are low.
The register table: design, measured, adjusted
One row per supply register and per return grille: location, size and type, the design airflow from the load calculation or the drawings, the airflow measured before adjustment, the damper adjustment made, and the airflow measured after. Sum the supplies and the returns and compare each with the equipment's rated airflow. The difference between the supply total and the equipment airflow is duct leakage, and the report should say so.
The method column
Flow hood, anemometer traverse, pitot traverse or static against the blower table: each gives a different number for the same airflow, and the report must record which was used at each reading. An air balancing report sheet download that has no method column produces numbers nobody can reproduce. Where a correction factor was applied for a register type, note it.
Tolerance and the sign-off
State the tolerance the balance was performed to, as a band around design, and mark each register in or out of it. List any register that could not be brought within tolerance and why: damper missing, duct crushed, branch undersized. End with the technician's signature and, for commercial work, the space for the engineer's or owner's acceptance. The report is a record of what was found as much as of what was fixed.
From the report to the record
File the completed report against the system in the unit record so the next technician starts from the balanced state. On a comfort complaint, the report is the first thing to read: if the register was within tolerance at balance and the room is now hot, something changed, and the report says what to compare. The airflow figures on the ACCA page linked below are the design starting point most residential reports are balanced toward; the equipment's data decides.
Questions people ask about air balance report template
Do residential jobs need an air balance report template?
Not as a contract deliverable, but as the document that ends a comfort complaint with evidence. A one-page version with the register table and the statics is enough.
What instruments does the report require?
A flow hood or anemometer for registers, a manometer for statics, and a tachometer and meter for fan data, each with its calibration date recorded.
Where can I find an air balancing report sheet download?
Build it from the sections above in a spreadsheet or in your field software; a downloaded sheet without a method column and system data is a table of unexplained numbers.