Each card = one supply grille / room.

❄ Cooling 🔥 Heating

Max static setting

Actual system SCFM?If the system can't deliver full design SCFM, enter the actual measured total here. Room targets will be proportionally adjusted so you can still balance fairly across rooms.

How to use this tool

HVAC Commissioning Field Tool — Eco Performance Builders

⚠ Why steady state matters

All measurements must be taken at steady state — when the system has been running long enough that temperatures have stabilized and are no longer changing. This typically takes 15–30 minutes of continuous operation.

Taking readings too early gives false results: supply temps will be warmer than actual (looks like less cooling), airflow calculations will be off, and EER will appear lower than real performance. Wait until your supply temp reading stops dropping before recording anything.

Signs you're at steady state: Supply DB is stable for 2–3 minutes • Return DB is stable • Outdoor unit has been running continuously • No recent thermostat changes

Measure tab — what to enter and when

Equipment & setup: Select the equipment model, enter elevation (affects air density calculations), and enter total system watts and air handler watts from your power meter at the time of measurement.

Outdoor DB: Measure at the outdoor unit with a thermometer. This is used to look up the rated EER from the equipment curve.

Return air grille: Measure temperature at the return grille face with the system running — this is the room air entering the system.

Supply grilles: Add one card per supply grille/room. Measure CFM with a flow hood or anemometer. Measure supply DB at the grille face. Name each room clearly — click the room name to rename it.

Plenums (optional but recommended): Enable “Measure supply & return plenums” to capture coil performance separately from duct losses. Insert probe into return plenum just before the coil, and supply plenum just after. This unlocks duct loss calculations.

ESP (external static pressure): Measure with a manometer across the air handler with system running. High ESP means restricted airflow — undersized ducts, dirty filter, or blocked coil.

Duct leakage: Enter CFM25 from a duct blaster test. System must be OFF for this test. This is a separate test from the commissioning run.

Results tab — how to read the numbers

Delivered EER vs rated: The most important number. Compares actual delivered cooling efficiency to the manufacturer’s rated EER at your outdoor conditions. 85%+ is good. Below 75% warrants investigation.

Coil EER vs rated: Efficiency at the coil (plenum measurements). If this is high but delivered EER is low, the losses are in the ducts.

Coil BTU/hr vs Delivered BTU/hr: Coil shows what the equipment is actually producing. Delivered shows what the rooms receive. The gap is your duct system loss.

Distribution loss: BTU/hr and % lost between coil and grilles. Under 10% is good. Over 20% indicates significant duct issues — uninsulated ducts, leaks, or long runs in hot spaces.

Duct leakage: Title 24 / ENERGY STAR standard is ≤6% of nominal CFM at 25 Pa. Above this suggests duct sealing is needed.

SHR (sensible heat ratio): Only shown when humidity is enabled. Typical comfort range is 0.70–0.80. Very high SHR (>0.85) means the system is doing little dehumidification — may indicate oversizing or low load.

Install tab — step by step guide

Step 1 — Nitrogen pressurization (500–600 psi): Pressurize with dry nitrogen. Allow pressure to equalize (may take a few minutes as temps stabilize). Record start pressure and outdoor temp. Hold ~15 minutes, record end pressure and temp. The app calculates a temperature-corrected result using Gay-Lussac’s Law — pass threshold is 1% of expected end pressure.

Step 2 — Ultrasonic leak check: With system still under nitrogen pressure, check every fitting with an ultrasonic detector. Check the box when all fittings pass.

Step 3 — Vacuum test: Pull vacuum to ≤200 microns. Close isolation valve. Hold 10 minutes — must stay at or below 300 microns to pass. Enter both readings and the app auto-calculates pass/fail.

Step 4 — Final leak check: After charging the system and running, check every fitting again with an electronic refrigerant detector. Check the box when all clear.

Lineset lengths & refrigerant: Enter actual line lengths per zone. If you provide the pre-charged length and adder rate from the equipment manual, the app calculates required oz adder automatically. Record refrigerant type and actual oz added for the report.

Equipment — adding custom models

The tool ships with Fujitsu mid-static and multiposition ducted models pre-loaded. To add other brands, go to the Jobs tab, scroll to the bottom and expand Equipment models.

You’ll need: model name, nominal BTU/hr capacity, and at least one EER data point at a known outdoor temperature. More data points (from the submittal or AHRI certificate) give more accurate interpolation. Enter EER from the AHRI 210/240 rating at 95°F outdoor — or multiple points across the curve for best results.

Exporting the PDF report

Tap Export PDF at the bottom of the Results tab. The report includes: customer and job info, key takeaways, manufacturer rated performance, coil and delivered performance, duct losses, airflow detail, and — if Install tab data is entered — a full installation commissioning page.

For multi-system jobs, the PDF exports the currently active system. Switch systems using the tabs at the top of Measure or Results before exporting.

Tip: Fill in customer name, address, and technician name on the Jobs tab before exporting — these appear in the PDF header.

Tips — best practices for accurate readings

• Wait for steady state before recording any temperatures. See the warning box at the top of this page.

• Measure supply DB at the grille face, not inside the duct. You want the temperature the room air is actually receiving.

• Return DB should be measured at the grille, not at the air handler. Duct losses between the grille and coil are real — measuring at the coil hides them.

• Use a calibrated thermometer. Cheap probes can be off by 2–5°F which significantly affects BTU calculations. For a 500 CFM system, 1°F error = ~540 BTU/hr error.

• Measure watts at the panel with a clamp meter on the circuit, not from nameplate data. Actual watts vary with conditions.

• For multi-head systems, all heads must be calling simultaneously for the outdoor unit to run at full capacity. Run all zones during the commissioning test.

• Outdoor temp matters. EER drops as outdoor temp rises. Test on a hot day (90°F+) for the most meaningful comparison to rated performance.

• Humidity toggle: Enable this when you have a sling psychrometer or digital RH meter for wet bulb. Without WB readings the tool calculates sensible BTU only — still useful, just incomplete for total capacity.

Key Takeaways