Attention All RESNET® Energy Rating Professionals!

Be a Hero and Help Save Duct Testing Exceptions_RESNET_EnergyLogic

Unfortunately, best-laid plans take some dramatic turns.

EnergyLogic’s goal of opening up duct testing exceptions led to a RESNET® proposal that went through the “sausage making” process of standards by committee.  What came out the other end was a major mixed bag of more strict requirements, but worst of all the proposed changes would take away the duct testing exceptions, creating a situation if kept as written where every duct system, regardless of location, would need to be tested for a HERS Rating.  This impacts all raters who use duct testing exemptions for ductwork inside conditioned space and you can make your voice heard.

We are asking all industry partners and stakeholders to take a few minutes and comment on this change.  The RESNET/ANSI due date for comment is January 28th.

Below is our proposed commentary. You will find the most critical change of allowing two pathways (keeping the current exception and allowing this new exception for ducts tested at rough) below, along with links to make your own comments.  Please copy and paste the proposal below into the RESNET system (from the links below) and make it your own with your own experience to lend.

Links to RESNET Site:

The proposed amended language is posted at Draft PDS-02, BSR/RESNET/ICC 301-2014 Addendum L-201x, Duct Leak to Outside Test Exception.

All proposed changes (denoted in underline-strikeout format) are open to comment.

To submit your comments click on RESNET Amendment Comment Online Form.

Comments are posted real time and you will be able to review comments that were submitted by clicking on Draft PDS-02, BSR/RESNET/ICC 301-2014 Addendum L-201x, Duct Leak to Outside Test Exception

EnergyLogic’s Official Comment:

The way this amendment is written and strictly interpreted, all ducts must be tested for total leakage. Since MINHERS, section 803.2 has been removed there are no other replacements found in ANSI 380 or 301 for duct leakage testing exception. This leaves a gap, where if strictly interpreted, all ducts must be tested for total leakage. This would also not align with most code jurisdictions across the nation and would not align with the ENERGY STAR exceptions for leakage to outside testing.

Is it RESNET’s intent to do away with that exception from leakage to outside when ductwork is fully ducted, in conditioned space, and visible at final? If so, RESNET should seriously consider the financial impact of this change to many builders across the country.  The cost/benefit of such a change to the rating system is very poor when you consider the leakage of systems within conditioned space will be within the thermal boundary (conditioned space/infiltration volume) of the home.  The testing would add a significant cost to the process with very little return in the potential energy reductions of those homes.

The proposed change would be a fine addition to the original exceptions in circumstances where ductwork would not be visible at final inspection. Since 803.2 had defined criteria where the ductwork was required to be visible at the final inspection to be exempt, the proposed exceptions from this amendment would be welcomed as an alternative pathway for ducts that are not visible at final inspection. We believe the intent of the amendment is to allow for an additional pathway for the exception from leakage to outside testing for homes already tested at rough inspection, but where ductwork was not 100% visible at the final inspection. We don’t believe that it was the committees intent to take the existing exception away but only add another pathway.  However, the intent of the amendment was not revealed with this proposal, and we are proposing to have the amendment spell this out more clearly to allow for 2 different exceptions, depending on whether ducts are 100% visible at final inspection.

Proposed Change to Amendment:

Revise Table 4.2.2(1) table note (m) as follows:

(m) Tested duct leakage shall be determined and documented by an Approved Tester using the protocols equivalent to those specified in Duct leakage shall be tested by an Approved Tester in accordance with requirements of Standard ANSI/RESNET/ICC 380-2016 to Section 803 of the Mortgage Industry National Home Energy Rating Systems Standards. with the following exceptions:

Exception 1 – When ductwork is 100% visible at the time of final inspection and all of the following criteria are met, the duct leakage to outside testing is not required and shall be assumed to be 0 cfm 25

  • 100% of the ductwork and air handler shall be visually verified and documented to be contained inside the Infiltration Volume.
  • The ductwork is 100% fully ducted. No building cavities shall be used as supply or return ducts.

Exception 2 – If ductwork is not 100% visible at final inspection and meets all of the criteria below, then the duct leakage to outside testing is not required, and duct leakage to outside may be deemed to be half of the measured total leakage when all of the following conditions are documented:

▪        100% of the ductwork and air handler shall be visually verified at a rough stage of construction and documented to be contained inside the Infiltration Volume.

▪        The duct system is 100% fully ducted. No building cavities shall be used as supply or return ducts.

▪        Airtightness of the duct system shall be tested in accordance with requirements of Standard ANSI/RESNET/ICC 380-2016 Total Duct Leakage Test (Section 4.4.1). The total leakage shall be less than or equal to the greater of: 4 cfm per 100 ft2 of Conditioned Floor Area served by the duct system being tested, or 40 cfm.

▪        Airtightness of the building enclosure shall be less than 0.15 CFM50 per square foot of enclosure area, when tested in accordance with requirements of Standard ANSI/RESNET/ICC 380-2016. The enclosure area is the sum of the areas of the surfaces that bound the Infiltration Volume.

<<<End of Official Comment>>>

Formatting Your Comments

When you copy/paste into RESNET’s system the color formatting doesn’t transfer.  RESNET requires that all proposed changes be colored red.

Please take a minute to reference the above red lettering and change appropriately in the RESNET commenting system.

Other Proposals to Consider

EnergyLogic has a few other proposals we will be making that will focus on the thresholds for the 2nd pathway.  We’ve decided to not include any proposed adjustments to the threshold in this proposal to make it easier for the committee to adopt this big ticket item.  If you have time, we encourage you to also comment and propose other edits with regards to the thresholds being proposed, but we think it would be most effective to do so in a separate proposal.  While the thresholds that the committee proposed are strict, if they adopt the two pathways we proposed above and also keep the thresholds as written this would be better than the alternative of no duct testing exception at all.

Thanks for your dedication to “EnergyLogic”al solutions!

 

Who to Contact:

Glenn Pease
Manager of Quality Assurance

Email Glenn
970-980-5919