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What Is a Duct Leakage Test?
Duct leakage testing measures how much air escapes from an HVAC duct system under controlled pressure. Stellar Building Performance uses a calibrated Retrotec Duct Tester to pressurize the duct system and measure leakage at the required test pressure, providing an objective measurement of duct system airtightness. Duct Leakage testing is required for some new homes in Florida for compliance with the Florida Energy Conservation Code.
Stellar performs both total duct leakage and leakage-to-outdoors testing depending on the construction stage and project requirements. Total duct leakage can be performed during rough-in or after construction and is especially useful for identifying installation deficiencies before walls and ceilings are closed. Leakage-to-outdoors testing is performed at final or post-construction when required by the project’s energy-code compliance documentation, and isolates measured leakage to air lost from the building.
Duct leakage testing is different from Blower Door Testing, which measures air leakage through the full building envelope rather than just the HVAC duct system. Depending on the project’s compliance path, one or both forms of testing may be needed as the home moves toward final inspection and closeout.
Testing at rough-in also gives the construction team an opportunity to address leakage while ductwork, boots, plenums, and connections are still accessible. If additional diagnostics are needed, Duct Smoke Testing is available upon request.
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Florida Energy Code Duct Leakage Requirements
Florida duct leakage testing requirements depend on the project’s energy-code compliance method, duct and air-handler location, and the performance values included in the project’s energy calculations. There is not one universal duct leakage test requirement that applies identically to every new home. If your local building department is requiring testing, and you’re unsure why, we are happy to help!
Duct Leakage testing by a certified individual from Stellar Building Performance provides the measurement needed to verify any applicable requirements have been met, and documentation for filing and approval by municipal building departments.
Why is Duct Leakage Testing Beneficial?
Duct Leakage testing helps ensure homes meet modern energy efficiency standards.
Excessive air leakage can cause:
Testing confirms the HVAC system’s air tightness, improves quality control, and verifies compliance with the required energy codes before final inspection. Passing your blower door test the first time helps avoid costly delays and rework before final inspection.
How We Keep Duct Leakage Testing Simple and Easy
From rough-in quality control to final energy-code documentation, we coordinate testing around the stage and requirements of your project.
1.
schedule testing
You contact us to schedule testing once the home is ready for inspection. We will verify necessity of testing or goals with quality inspection.
2.
onsite testing
Our experienced inspectors seal registers and openings temporarily and our calibrated Retrotec duct tester is connected to the HVAC system for testing.
3.
Diagnostics and Measurements
The duct system is brought to the required test pressure and the measured leakage is recorded using the method appropriate to the project’s construction stage and compliance requirements.
4.
REVIEW RESULTS & DIAGNOSTICS with instant email reporting
If leakage is higher than expected, we explain the result and discuss practical next steps. Duct smoke testing is available as a separately approved diagnostic service when locating individual leakage points would be helpful.
5.
Ready for Final Inspection approval
Once results are confirmed compliant, the building department issues certificate of occupancy needed to close out your buildng permit!
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Local duct leakage testing throughout Brevard County, Indian River County, and St. Lucie County.
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Frequently asked questions about Duct Leakage Testing
No. A duct leakage test measures leakage from the HVAC air-distribution system. A blower door test measures leakage through the building envelope. They are different performance tests and may be used independently or together depending on the project’s energy-code and performance requirements.
Total duct leakage measures all leakage from the HVAC duct system, regardless of where the leaking air travels. Leakage-to-outdoors testing isolates the portion of duct leakage that communicates with outdoors or spaces outside the building’s conditioned enclosure. Stellar performs either method depending on the project stage, energy calculations, and applicable compliance requirements.
Yes. Total duct leakage testing can be performed during rough-in, and this is an excellent time to test the system. With the ductwork still exposed, excessive leakage can be investigated and corrected without opening finished walls or ceilings later.
Rough-in testing should be coordinated after enough of the duct system has been installed and sealed for a meaningful test, but before drywall or other finishes limit access to the ductwork. Send Stellar the project stage and available energy documents, and we can help determine whether the system is ready for testing.
Not necessarily. The current Florida prescriptive documentation includes separate total duct leakage criteria for systems tested with the air handler installed and systems tested before the air handler is installed. The appropriate setup depends on the project and compliance method.
We explain the measured result and help the project team understand the next step. During rough-in, the HVAC contractor can often correct problem connections while everything is still accessible. If locating individual leakage points would be helpful, Stellar also offers separately approved duct smoke testing, followed by retesting when needed. If testing isn’t performed until final/post construction, location leakage becomes more tricky. Smoke testing is still a viable option, but pinpointing leakage may require coordination with an HVAC contractor.
No. Duct smoke testing is a separate diagnostic service available upon request. Stellar carries the diagnostic equipment needed to perform smoke testing and can often add it while already onsite, but the additional work is only performed after the client approves the service and pricing.
Duct Leakage Testing Code References
Duct Leakage Test Florida Requirements Explained
Duct Leakage Testing is occasionally required for residential dwellings per the Florida Building Code for Energy Conservation by requirements outlined in sections R402-R405. Testing by Stellar Building Performance will be in compliance with these sections. Our specialists are experts on the building codes, and can answer any questions you may have about the codes, but feel free to read excerpts from the current building code, 2023 Florida Building Code, Energy Conservation, Eighth Edition, below.
questions? give us a call, this is our specialty!
BIG CHANGES COMING IN 2026 FLORIDA BUILDING CODE UPDATES
Duct Leakage testing to be required on all homes with very few exceptions, more stringent compliance targets, mechanical ventilation testing & more. Read our updates bulletin below.
2026 Florida Building Code Energy Conservation: What Builders Need to Know
This code line explains testing procedures.
R403.3.3 Duct testing (Mandatory)
Ducts shall be pressure tested to determine air leakage by one of the following methods:
1.Rough-in test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the system, including the manufacturer’s air handler enclosure if installed at the time of the test. All registers shall be taped or otherwise sealed during the test.
2.Postconstruction test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the entire system, including the manufacturer’s air handler enclosure. Registers shall be taped or otherwise sealed during the test.
Exceptions:
1.A duct air leakage test shall not be required where the ducts and air handlers are located entirely within the building thermal envelope.
2.Duct testing is not mandatory for buildings complying by Section R405 of this code. Duct leakage testing is required for Section R405 compliance where credit is taken for leakage, and a duct air leakage Qn to the outside of less than 0.080 (where Qn = duct leakage to the outside in cfm per 100 square feet of conditioned floor area tested at 25 Pascals) is indicated in the compliance report for the proposed design.
A written report of the results of the test shall be signed by the party conducting the test and provided to the code official.
This code line explains result requirements under the most common energy code compliance path in Florida, the Performance Path.
R403.3.4 Duct leakage (Prescriptive)
The total leakage of the ducts, where measured in accordance with Section R403.3.3, shall be as follows:
1.Rough-in test: The total leakage shall be less than or equal to 4 cubic feet per minute (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area where the air handler is installed at the time of the test. Where the air handler is not installed at the time of the test, the total leakage shall be less than or equal to 3 cubic feet per minute (85 L/min) per 100 square feet (9.29 m2) of conditioned floor area.
2.Postconstruction test: Total leakage shall be less than or equal to 4 cubic feet per minute (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area.
In some instances, to comply with building code, your project may require additional testing. Compliance documents required as part of your permit package, commonly called Energy Calculations, determine code requirements for your specific project. These code lines outline Duct Leakage Test requirements. We can test this while onsite for your Blower Door Test if it is required.
R405.2.3 Duct air leakage testing.
In cases where duct air leakage lower than the default Qn to outside of 0.080 (where Qn = duct leakage to the outside in cfm per 100 square feet of conditioned floor area tested at 25 Pascals) is specified for the proposed design, testing in accordance with Section R403.3.2 shall verify a duct air leakage rate not exceeding the leakage rate of the proposed design. Otherwise, in accordance with Section R403.3.3, duct testing is not mandatory for buildings complying by Section R405.
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Similar Services
Stellar Building Performance provides energy-code testing and building-performance diagnostics for new construction throughout Florida’s Space Coast and Treasure Coast.
Blower Door Testing
Verify duct system airtightness using professional duct blaster testing required for new construction inspections.
Duct Smoke Testing
Use diagnostic fog to help locate specific duct leakage points when an HVAC system needs further investigation.
Helping Builders Keep Duct Testing and Energy-Code Closeout Moving
Fast Scheduling
Builders get testing scheduled quickly to avoid delays.
accurate results
Professional equipment ensures reliable measurements.
immediate reports
Documentation provided immediately by email for inspection approvals.
