Proposed Changes to PTCS Duct Standards April 7 th, 2009 Regional Technical Forum

Subcommittee Conference Call February 24, 2009 Attendees: – Mark Johnson – David Hales – Andres Morrison – Bruce Manclark – Mark Jerome – Brady Peeks – Adam Hadley Outcome: Developed recommended changes to the PTCS Duct Standards

PTCS Duct Standards Subcommittee-Recommended Changes 1.Put all “duct testing procedures” language in a separate document. 2.Remove “program standards” language, which required a specific pre-existing leakage rate for manufactured homes (the dry hole test). (Old p.7 #2) – Note: This is not a recommendation to programs to stop pre-screening for payment, simply a recommendation to take the language out of the duct standards document. 3.Significantly reformat/organize document to make it “spec-like”.

PTCS Duct Standards Subcommittee-Recommended Changes 4.Add a requirement to replace insulation. (New 5.2) New Language: Where a large section of duct insulation is removed, the insulation shall be re-installed and securely attached to the duct system. Recommended methods include the use of twine. Mastic will not effectively hold insulation in place.

PTCS Duct Standards Subcommittee-Recommended Changes 5.Add the following External Static Pressure “should” to New Homes and Existing Homes/New Ducts section: (New and 6.2.5) New Language: “If a new air handler is being installed, the total external static pressure acting on the system air handler should be tested with approved instruments and recorded at time of startup. A measured external static pressure of more than 0.8” (200 Pa) should cause installer to consider taking corrective measures with system ductwork.“ Note: This is not a “shall” in the duct specs because it is a “shall” for PTCS heat pumps. In the case of a gas furnace, a “shall” here would hand this responsibility to the duct sealing contractor - something the subcommittee didn’t want to do. Furthermore, the existing contractors are not trained to do this test.

PTCS Duct Standards Subcommittee-Recommended Changes 6.Update the supply side only test leakage requirements (Old p.5 section C; New 6.3.4) Old Language: In extreme cases where return ducts are inaccessible, compliance with either (0.10CFM50 x ft2) or (50% reduction) may be accomplished by testing the supply side only New Language: In cases where return ducts are inaccessible, compliance with (0.10CFM50 x ft2) or (50% reduction) may be accomplished by performing the Duct Leakage to the Exterior test on the supply side only (using the more stringent of the two – whichever is less). Reason for the Change: The subcommittee agreed this is what has been intended all along, and that the previous specification was in error.

PTCS Duct Standards Subcommittee-Recommended Changes 7.Modify Manufactured Home language: (Old p.7 #5; New 6.4.4) Old language: If the final tested leakage rate is greater than 75 CFM 50, the air handler-to-duct transition connection shall be sealed with proper materials. New language requires: If the final tested leakage rate is greater than 50 CFM 50 for single wide homes, plus an additional 30 CFM 50 for each additional section, the air-handler transition-to-trunk duct connection shall be sealed.

PTCS Duct Standards Subcommittee-Recommended Changes 8.Remove all CAZ testing requirements; modify CO alarm requirement. (Old p.3 #3&4, p.4 #3&4, p.5 #2&3, p.7 #3&4; New 7.1) Old Language: Based on the protocol for “Combustion Appliance Zone Pressure Testing” forced air system operation shall not de-pressurize a combustion appliance zone by more than 3 Pascals. When combustion appliances are located within a conditioned space a UL listed carbon monoxide alarm, or equivalent must be installed. New Language: Whenever there is a Combustion Appliance present in the house, garage, or other attached space, a UL listed, C-UL listed, or equivalent carbon monoxide alarm shall be installed in accordance with the carbon monoxide alarm manufacturer’s instructions. Reason for the Change: The CAZ test is not always a reliable test. Test repeatability is questionable. It is also not possible to perform the test in all weather conditions.