Code Cycle: 2016 & 2019 Standards
Reference: CalCERTS Alterations Training Manual Chapter 7, Section 7
The seal all accessible leaks test is applicable only to existing duct systems that are unable to pass using either option 1 or option 2. However, seal all accessible leaks require that option 1 be performed in order to measure the leakage before commencing duct sealing. There is no pass/fail criteria associated with the measured duct leakage. A Pass/fail is dependent entirely on the outcome of smoke and visual verification's included in this option. Systems using this test option to demonstrate compliance may not be included in sample groups. The test protocol from the Residential Appendices is included here followed by general notes about performing the test.
Note: Seal all accessible leaks is NOT an option for a new duct system!
RA22.214.171.124.5 - Sealing of All Accessible Leaks
For altered existing duct systems that are unable to pass either the Total Duct Leakage test (option 1) or the Duct Leakage to Outside (option 2), the following procedure shall be used:
1. Complete option 1 to measure the total leakage before commencing duct sealing.
2. (Installer) Seal all accessible ducts.
3. After sealing is complete, retest the duct system using option 1.
4. Complete the Smoke Test as specified in RA126.96.36.199.6.
5. Complete the Visual Inspection as specified in RA188.8.131.52.7.
The Sealing All Accessible Leaks protocol uses the total leakage duct test to document the magnitude of duct leakage and subsequent improvement achieved by the installer. There are no pass/fail criteria associated with the measured duct leakage. If at any time the installer is able to reduce the total duct leakage to less than 15%, the Rater reverts back to the Total Leakage Duct Test (option one), avoiding the Smoke and Visual verification's required by this compliance option.
The following protocols for the Smoke Test and Visual Verification are the core elements of Option 3, Sealing of All Accessible Leaks test protocol. Using this option to demonstrate compliance requires diligence on the part of the Rater to ensure that the system in fact does pass. Performing the Smoke and Visual verification's will significantly increase the time and effort required to demonstrate compliance.
RA184.108.40.206.6 - Smoke Test of Accessible Duct Sealing
For altered existing ducts that fail the leakage tests, the objective of the smoke test is to confirm that all accessible leaks have been sealed. The following procedure shall be used:
1. Inject either theatrical or other non-toxic smoke into a fan pressurization device that is maintaining a duct pressure difference of 25 Pa relative to the duct surroundings, with all grilles and registers in the duct system sealed.
2. Visually inspect all accessible portions of the duct system during smoke injection.
3. The system shall pass the test if one of the following conditions is met:
a. No visible smoke exits the accessible portions of the duct system.
b. Smoke only emanates from the furnace cabinet which is gasketed and sealed by the manufacturer and no visible smoke exits from the accessible portions of the duct system.
The Smoke Test makes use of a theatrical fog machine during duct pressurization to make the leaks in a duct system visible. It is a good idea to use a professional quality fog machine rated at around 1000W. Fog machines with remote controls are suggested to allow the Rater to modulate the flow of smoke so you do not fog over the entire space. Good lighting is essential to identifying leaks in attics and crawlspaces. The test is done with the Installer on-hand and the leaks are sealed as they are identified. With package units, do not forget to inspect up on the roof where the equipment is set onto the “curb” or if placed on the ground next to the house, check around the supply and return where it enters the home.
The seal all accessible leaks protocol requires that the HERS Rater perform a smoke test and then identify where smoke is leaking out of the duct system. The installation contractor is responsible for sealing the accessible portions of the duct system ONLY. Finally, this test is complete when the HERS Rater visually verifies that all leaks have been sealed from the accessible portions of the duct system. The system shall pass the test if one of the following conditions is met:
1. No visible smoke exits the accessible portions of the duct system, or,
2. Smoke only emanates from the furnace cabinet which is gasketed and sealed by the manufacturer and no visible smoke exits from the accessible portions of the duct system.
Note: A drop cloth should be used under your fog machine to protect the floor covering. The fog produces a residual that could cause damage to the floor and or duct tester. Follow the manufacturer’s recommendation on cleaning your equipment after use.
RA220.127.116.11.7 - Visual Inspection of Accessible Duct Sealing
For altered existing ducts that fail the leakage tests, the objective of this inspection in conjunction with the smoke test (RA18.104.22.168.6) is to confirm that all accessible leaks have been sealed. Visually inspect to verify that the following locations have been sealed:
1. Connections to plenums and other connections to the forced air unit.
2. Refrigerant line and other penetrations into the forced air unit.
3. Air handler door panel (do not use permanent sealing material, metal tape is acceptable).
4. Register boots sealed to surrounding material.
5. Connections between lengths of duct, as well as connections to takeoffs, wyes, tees, and splitter boxes.
The Visual Verification is a specific list of locations that the Installer must seal regardless of the results of the Smoke test. For instance, the Rater would have the Installer remove register grilles to verify that all register boots are sealed to the surrounding material (e.g. drywall or sub-floor). Sealing must be done by the Installer using approved ducting materials, sealants and tapes as specified in Chapter 4 of the Residential Compliance Manual.
A consequence of the visual verification's is that systems with platform plenums which are not fully lined with approved ducting materials need to be retrofitted with duct-board or sheet metal. In many cases platform plenums can be accessed by removing the return register. It may not be convenient but it is accessible. By removing the return register grille, platform plenums become accessible and therefore must be sealed when the visual verification is triggered. Where systems can show compliance without triggering the Visual Verification, those systems could retain pre-existing platform plenums constructed of non-approved materials.
In some cases, platform plenums are not accessible because the return register(s) are too small or there are framing members, electrical wiring, and plumbing or gas lines obstructing access. In these cases, the Rater should take photographs to document why these systems are deemed inaccessible. For more on accessibility, see article titled "When is a Duct System Considered Accessible".