BSR/RESNET/ICC 301-2014 Addendum L-20xx, draft PDS-02, Exception to Duck Leakage to Outside Testing Comments Submitted

The following comments have been submitted:

Comment #1

Page Number: 1
Comment Intent: Not an Objection
Comment Type: Editorial

Comment:

Section (m) revisions state: "Duct leakage shall be tested and documented by an Approved Tester in accordance with requirements of Standard ANSI/RESNET/ICC 380" [bold and italics added for emphasis]

Does Standard ANSI/RESNET/ICC 380 specify how to document test results? If not, revisions may be needed to the Addendum that specify how test results will be documented.

Proposed Change:

None provided.

Comment #2

Page Number: 1
Paragraph / Figure / Table / Note: Table 4.2.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

The conditions required for omitting leakage to outside testing are far too onerous.

Energy Star allows not testing leakage to outside in my climate zone (2) if ...

     Leakage to outside is equal to or less than 4 cfm/100'

                           OR

     ACH/50 is equal to or less than 3.

You propose requiring BOTH Energy Star's leakage to outside requirement AND infiltration 3 times tighter than Energy Star's requirements.

    For a 2,000 sq ft house with 9' ceilings - or 18,000 cu ft

    Your 0.15 cfm/sq ft = 300 cfm blower door number

A 300 cfm blower door number in an 18,000 cu ft house is 1 ACH/50.  That is ridicously low and will rarely be achieved, so waiving the leakage to outside test will seldom happen.

 

Also, because waiving the leakage to outside test REQUIRES first doing the total leakage test, Raters will always actually perform the leakage to outside test - since they will have the equipment already set up.

Thus the stringency of your proposed requirement will render waiving the leakage to outside test irrelevant.

Once again, RESNET requirements fail in the real world.  You have too many ivory tower eggheads making the rules.

Why not emulate Energy Star ?  They are realistic.

 

Jon Maxwell

Energy Efficiency NOW

 

 

 

 

 

 

 

 

 

Comment #3

Page Number: 1
Paragraph / Figure / Table / Note: 4.2.2(1) Note M
Comment Intent: Objection
Comment Type: Technical

Comment:

The conditions required for omitting leakage to outside testing are far too onerous.

Energy Star allows not testing leakage to outside in my climate zone (2) if ...

     Leakage to outside is equal to or less than 4 cfm/100'

                           OR

     ACH/50 is equal to or less than 3.

You propose requiring BOTH Energy Star's leakage to outside requirement AND infiltration 3 times tighter than Energy Star's requirements.

    For a 2,000 sq ft house with 9' ceilings - or 18,000 cu ft

    Your 0.15 cfm/sq ft = 300 cfm blower door number

A 300 cfm blower door number in an 18,000 cu ft house is 1 ACH/50.  That is ridicously low and will rarely be achieved, so waiving the leakage to outside test will seldom happen.

 

Also, because waiving the leakage to outside test REQUIRES first doing the total leakage test, Raters will always actually perform the leakage to outside test - since they will have the equipment already set up.

Thus the stringency of your proposed requirement will render waiving the leakage to outside test irrelevant.

Once again, RESNET requirements fail in the real world.  You have too many ivory tower eggheads making the rules.

Why not emulate Energy Star ?  They are realistic.

 

Jon Maxwell

Energy Efficiency NOW

 

Comment #4

Page Number: 1
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

The third condition for avoiding duct leakage to outside testing requires a total duct leakage score of under 4 CFM/100 square feet of enclosure to be verified. This condition does not specify when total duct leakage can or should be tested. SWA believes that this bullet point should clarify that total duct leakage can be tested at rough-in when no sheetrock is present. We believe this may be implied but that it should be explicit.

Proposed Change:

Airtightness of the duct system shall be tested in accordance with requirement 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.The total duct leakage test can be performed at at the rough-in stage before sheetrock has been installed.

Comment #5

Page Number: 1
Comment Intent: Objection
Comment Type: Technical

Comment:

RESNET continues to put raters in an awkward situation with regards to duct testing with respect to energy code compliance, of which harmonizatoin with the code should be a #1 priority. According to most modern model energy codes, if 100% of ducts are within conditoined space, the duct test can be exempted. This saves raters a lot of time, and subsequently builders a lot of money. Furthermore, in situatoins where the ducts are all within conditoined space, the result of the test is rarely in question... the ducts almost never leak substantailly to outside... and typically only will if there is a fresh air duct entering the return plenum (I have submitted proposed standards amendments to address how these openings should be treated).

I encourage RESNET to take this opportunity to simplify its required testing protocols to come more in line with existing energy code protocols, so that raters aren't made to run tests that for all practical purposes is a waste of time. This is yet another area where a lack of consistency comes into play, and an area where raters/providers can and do compete with one another by choosing to follow code interpretations instead of RESNET standards.

Maintaining the requirement to perform Total Leakage won't ultimately save many raters or their builders much time, money or effort as you stilll have to expend the money and effort to set up the system, tape the ducts, run the test, untape the ducts, etc.

Proposed Change:

Delete everything after

"100% of the ductwork and air handler shall be visually verified and documented to be contained insidethe Infiltration Volume"

Comment #6

Page Number: 1
Comment Intent: Objection
Comment Type: General

Comment:

I've been a rater for nine yearsr in Aspen Colorado, do about ten rating a year. Telluride, Snowmass and other resort communities are my domain. It seems to me that RESNET assumes that every house is some 2,000 sf ranch-burger in a subdivision. My average house size is about 5,700 sf, some as large as 22,000 sf, set into the side of a mountain. These homes often have seriously complex mechanical systems custom designed by mechanical engineers; radiant and force-air running at the same time, fan coil units, ductless ASHPs, GSHP and thermal solar- all in one system. (PS I know REMrate cannot handle this and the resulting rating is largely bullshit.) Nobody wants me hooking a fan up to this $500,000 system. Often the vents are 20' off of the ground. This is scaffolding conditions. No way I'm carrying a folding ladder big enough to mask off those vents. Often the vents are 1" x 48" set framlessly into plaster- a there is no way they are going to let me put painter tape and ductmask on that wall! I even see vents set behind the bathroom mirrors. (unaccesible)

As long as I'm commenting... I'm going to attach a letter I wrote to my provider a while back. Maybe it will magically find its way to someone that will listen.

Confluence Architecture is an architecture & sustainability firm, 18 years old now. RESNET needs to back off on the rules and requirements and let me make some money if this rating stuff is going to be viable for our firm. 

HERS ratings are barely worth doing for us. The low volume coupled with the unbelievably high cost (and hassle factor) of maintaining the rater certification makes the percentage of overhead costs discouragingly high. Still, I stick with it because I believe in the work.

I think it is ridiculous to have a QA program that is so much more onerous than programs for plumbers, electricians, surveyors, appraisers, real estate agents, engineers and architects. As a Colorado architect I take responsibility for millions of dollars of construction and the life and limb of the building occupants and my license costs $35 a year, no continuing education reporting required.

If RESNET is trying to make ratings more accurate and consistent; they should get us some decent software (REMrate was a piece-of-shit a decade ago with ZERO improvement in that time.) Driving 300 miles to watch me run a blower door every year doesn’t help anybody. Actually, it’s a little insulting. Imagine someone coming around every year to make sure an electrician still remembered how to use his multi-meter. In my opinion, a mandatory one-day industry update and refresher course every second or third year would be far more useful than QA in it’s present form.

So in summary, QA is a ridiculous burden and overhead cost that will force this low-volume rate to move on to greener pastures. If you require duct testing on every rating- I am gone!

Mark McLain

9920829

 

Comment #7

Page Number: 1
Paragraph / Figure / Table / Note: Last bullet point
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

The last bullet point currently reads "Airtightness of the building enclosure shall be less than or equal to 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."

Please clarify for a multifamily building scenario. In a multifamily building, would the "building enclosure" in the text above be the compartmentalization leakage limit for an individual apartment unit? Or could it be the leakage limit of the entire building, assuming a whole building blower door test is performed? Thanks.

Comment #8

Page Number: PDS-02
Comment Intent: Objection
Comment Type: General

Comment:

Draft PDS-02, BSR/RESNET/ICC 301-2014 Addendum L-201x, Duct Leak to Outside Test Exception

 

It was pointed out to me that this proposed amendment, well founded as it is, ignores duct testing realities which have evolved. I don't find an appropriate place to comment on this unfriendly website so hopefully this will do.
Until the proposal identifies when carefully administered, time consuming tests do not need to be administered then this proposal should be tabled. Testing time should be money for us 3rd party independents. We charge according to time spent and we should not have to charge our customers for something they don't need. Hopefully your doctor doesn't do and charge you for unnecessary tests.
Rick Jenkins RESNET Rater

Comment #9

Page Number: PDS-02
Comment Intent: Objection
Comment Type: General

Comment:

Draft PDS-02, BSR/RESNET/ICC 301-2014 Addendum L-201x, Duct Leak to Outside Test Exception

 

It was pointed out to me that this proposed amendment, well founded as it is, ignores duct testing realities which have evolved. I don't find an appropriate place to comment on this unfriendly website so hopefully this will do.
Until the proposal identifies when carefully administered, time consuming tests do not need to be administered then this proposal should be tabled. Testing time should be money for us 3rd party independents. We charge according to time spent and we should not have to charge our customers for something they don't need. Hopefully your doctor doesn't do and charge you for unnecessary tests.
Rick Jenkins RESNET Rater

Comment #10

Page Number: NA
Comment Intent: Objection
Comment Type: Technical

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:

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.

Comment #11

Page Number: 1
Comment Intent: Objection
Comment Type: General

Comment:

If 100% of the ductwork is verified to be within conditioned space, in what fantasyland are we living that we have leakage to outside?  And since total leakage, when ducts are entirely within conditioned space, has no effect on the HERS rating, why are we wasting our time?  Are there any HERS raters on this committee?

Proposed Change:

change entire text to:

When 100% of the ductwork and air handler is visually verified and documented to be contained inside the conditioned space, duct leakage testing is not required.

Comment #12

Page Number: A
Comment Intent: Objection
Comment Type: Technical

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:

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.

Comment #13

Page Number: 1
Paragraph / Figure / Table / Note: Table 4.2.2(1) table note (m)
Comment Intent: Objection
Comment Type: General

Comment:

Standard application of HERS Ratings and standard construction practice in Massachusetts is advanced from much of the country and the exceptions to duct-leakage to outside have been common and have been granted consistently for many years. The exceptions have been informed by as informed by the Massachusetts Residential New Construction Program, the 2015 IECC, ENERGY STAR, and REM/Rate. As proposed we would need to do additional testing where not previously required and enter higher values for duct leakage to outside if the exception were taken.  For consistency in Massachusetts, one of the more advanced States in the country with respect to energy code and incentive programs, we need to re-write this duct leakage test exception to be more favorable as follows:

Proposed Change:

Duct leakage shall be tested and documented by an Approved Tester in accordance with requirements of Standard ANSI/RESNET/ICC 380

Exception: When all of the following conditions are met and documented, duct leakage to outside testing is not required, and 0 cfm may be entered in the energy model for duct leakage to outside.  

?        100% of the ductwork and air handler shall be visually verified and documented to be  sealed and 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 building enclosure shall be less than or equal to 0.3 CFM50 per square foot of enclosure area, when tested in accordance with requirements of Standard ANSI/RESNET/ICC 380.  The enclosure area is the sum of the areas of the surfaces that bound the Infiltration Volume. 

Additionally, when tested in accordance with requirements of Standard ANSI/RESNET/ICC 380,  Total duct leakage may be used in place of Leakage-To-Outside. If this Total leakage test is done at rough then the boots in unconditioned space must be visually inspected to be sealed to the flooring or sheetrock at final inspection.

Comment #14

Page Number: 1
Comment Intent: Objection
Comment Type: General

Comment:

As written there is no exception to duct leakage testing. All duct systems would have to be tested for total duct leakage and very few would qualify for the duct leakage to outside exception. A 2000 s.f. building with 9' ceilings would have to be 1 AC/h or less. Resnet should align with the IECC and allow an exception when all ductwork and air handler are located in conditioned space. 

Proposed Change:

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 and documented 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. Exception: Duct When of the foall llowing conditions are met and documented, 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 shall be assigned to duct leakage to outside: ? 100% of the ductwork and air handler shall be visually verified 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 or equal to 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.

 

Comment #15

Page Number: 1
Comment Intent: Objection
Comment Type: General

Comment:

That seems like a really long way to say we must do duct testing on all systems regardless of the location unless the blower door is about 1ACH.  Here on long island we work on very big estates with sometimes a dozen hvac systems all inside a completely foamed out house.  Telling these clients I need to charge them for duct testing multiple systems with leakage, meanwhile we all know there is no where for this to leak, would be slap in the face to my clients and they would start to belive im just making this stuff up for a money grab.  Its hard enough getting builders to pay our fee's. Adding this would not go over well especially when everyone with a brain knows it is a collasal waste of time.  I couldnt reject this idea more. 

Comment #16

Page Number: 1
Comment Intent: Objection
Comment Type: General

Comment:
In our opinion, 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 eliminate that exception from leakage to outside when ductwork is fully ducted, in conditioned space, and visible at final? If so, RESNET must consider the financial impact of this change to builders across the country.  The cost to builders of such a change to the rating system will result in very low overall benefits when considering 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 an acceptable addition to the original exceptions in situations where ductwork is not visible at final inspection. Since 803.2 had defined criteria where the ductwork was required to be visible at the final inspection in order to be exempt from testing, the proposed exceptions from this amendment would be welcomed as an alternative pathway for ducts that are not visible at final inspection.
 
We believe that 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 doubt that it was the committee's intent to eliminate the existing exception, but rather to add a second, alternate 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 two different exceptions, depending on whether or not ducts are 100% visible at final inspection.
Proposed Change:

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 the following conditions are true: 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>>>

Comment #17

Page Number: NA
Comment Intent: Objection
Comment Type: Technical

Comment:

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:

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.

Comment #18

Page Number: NA
Comment Intent: Objection
Comment Type: Technical

Comment:

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:

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.

Comment #19

Page Number: NA
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

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:

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>>>

Comment #20

Page Number: 1
Comment Intent: Objection
Comment Type: Technical

Comment:

As my Provider pointed out, 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:

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.

Comment #21

Page Number: 1
Paragraph / Figure / Table / Note: same
Comment Intent: Objection
Comment Type: Technical

Comment:

 

The thresholds for Air Tightness are more strict than even the most leading builders in Colorado are able to obtain.  We have pulled data on a nationally recognized, award-winning, high-performance builder in Colorado and their average is 0.219 cfm50 per sf of enclosure area.  Usually there is an opportunity to attach supporting documents, however, I did not see a space for this one. Please see the link here to a Google Sheet with supporting data.

 

https://docs.google.com/spreadsheets/d/1Pdl2NOhabwbEzj1N3wJPXrU7cT1d_3Gz5tXbbsmiSSI/edit?usp=sharing

 

Given this is one of our best builders, we recommend using 0.25 cfm50 per sf of enclosure area. In some parts of the country they are happy when they hit this level of tightness but, typically aim for 0.30 cfm50 targets.  

 

Instead of proposing one big change,  we are submitting these changes individually in hopes that all of the proposed changes will be considered on their own merit. We also hope this will help in facilitating a discussion from the committee about each change.

 
Proposed Change:

Proposed Change to Amendment:

 

Exception: 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 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 0.25CFM50 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.

 

Comment #22

Page Number: 1
Paragraph / Figure / Table / Note: same
Comment Intent: Objection
Comment Type: Technical

Comment:

 

I would like to address our 2nd exception when ducts are not visible at final because there are covered by drywall.  I’m wondering if all ducts are:

 

A. located within conditioned space

B. the house is tested to be tight

C. the ducts are tested to be tight

 

Then how is it justified to assign 50% of the total leakage as a leakage to outside result?  

 

Given all the criteria being proposed, it seems a logical conclusion that the path of least resistance for the duct leakage would be to the inside of the house because air sealing efforts would be focused to build a house that is tight to the outside (as proven by the air tightness thresholds).  Couple that with the fact that the ducts would be generally tight to code standards at 4% total leakage and would be 100% inside conditioned space, it is reasonable to conclude that any left over leakage in the ducts would move through holes to the interior, particularly since the house would be tight to the outside.

 
Proposed Change:

(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 and documented 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.

 

Exception:  Duct  When all of the following conditions are met and documented, 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  0 cfm 25 shall be assigned to duct leakage to outside:

 

Comment #23

Page Number: 1
Comment Intent: Objection
Comment Type: Technical

Comment:

Energy modeling for the HERS Index score utilize duct leakage to outside testing results as a means to quantify the impact of energy loss through ductwork that is leaking to the outside.  The majority of this loss occurs through leaky ducts that are located outside of the buildings thermal envelope as defined by RESNET’s infiltration volume.  We know through experience that when testing ductwork that is located 100% within the infiltration volume of a tight home that its leakage is not affecting the HERS modeling software.

When modeling in Ekotrope and REMRate duct location trumps leakage to outside’s impact on the HERS index.  If all the duct work is modeled as inside the conditioned space i.e. inside the infiltration volume, you can input as much as 90-300 CFM of leakage to outside without impacting the HERS Index depending on the software used.  Conversely, if one inputs zero leakage to outside and changes the location from conditioned to ventilated attic the HERS Index changes by 5-12 point on average.  Our experience when testing duct system for leakage to outside when they are hard ducted and located entirely within the infiltration volume in a tight home of 3 ACH50 or better is that the measure leakage is between zero and 25 CFM, which may be accurate, but which is also well within the level of error of the equipment and well below a level that impacts the HERS index.

There is also a disconnect between the IECC and the proposal that was put out for comment.  The IECC only requires a total duct leakage test be performed if any portion of the duct system is located outside of the buildings thermal envelope i.e. infiltration volume.  For the Simulated Performance and the Energy Rating Index paths of code compliance, duct leakage to outside also becomes a variable that helps to provide additional flexibility for compliance.  This proposal would require 100% testing at a rough stage of construction even when 100% of the duct work was located within the building envelope and the IECC would not require any level of testing of the duct system, because this proposed exception is to a section of the standard that says LTO testing must occur when portions of the duct are not visible.

To my knowledge the impact of house tightness (infiltration/exfiltration) on the amount of duct leakage to outside has not been studied or quantified beyond the anecdotal experience of Raters.  As a thought experiment, if all the ducts are located inside the infiltration volume it may seem obvious that that the tighter the home the less duct leakage to outside would occur.  However, what is the impact of duct leakage through the envelope during times of infiltration vs. exfiltration? 

At EnergyLogic we have unscientific data that indicates that there is a diminishing return on house tightness first on the HERS Index and second on duct leakage to outside. We tested 188 homes of a nationally recognized high-performance builder we worked with in 2017.  Their average house tightness was 3.2 ACH50 and their average duct leakage to outside was 1%. They do not build 5000 sqft homes, but if they did their average duct leakage to outside would be 50 CFM which is below what impacts the modeling of the HERS index.  What I am pointing out here is that the .15 CFM/ft2 of enclosure area is a ridiculously tight standard to hold a home to in order to use the proposed exception. I can see the logic of requiring that the house be tight and using a CFM/ft2 of enclosure area matrix, however, two things need to be assessed.  First, introducing a new matrix that is not even used by the rating software creates confusion in the marketplace so should be introduced with a corresponding ACH50 number. Second, staying in alignment with the IECC makes the most sense.  The tightest the IECC requires a home to be built to is 3ACH50 and research that I did for my proposed IECC air leakage testing amendment for the 2018 IECC determined that .24 CFM50/ft2 of enclosure area was roughly equivalent.  From my perspective having a house that is less than or equal to 3 air changes per hour or 0.24 CFM50 per square foot of enclosure area is all that is needed to allow an exception to duct leakage testing to outside at long as location and construction are documented.

Documenting the location and construction of the duct work is a crucial component of this proposed amendment. We want to ensure that if a rating is done on a home that has not had a rough inspection that a duct leakage test to the outside is still required. On the other side of the coin, we want to ensure that the home that is using the exception is qualified.  Documentation is needed to help the Quality Assurance required by RESNET to be carried out in a successful manor.

All testing has an economic impact. The reality is that the majority of testing occurs for builders that must pay for additional testing requirements that RESNET implements.  In this case duct leakage testing would be required regardless if the ducts were not visible at the time of testing or with this exception as released for comment, at a rough stage of construction to avoid testing at final for leakage to outside.  Some consideration should be given to the cost benefit ratio and the impact on the growth and sustainability of our industry.  The proposed changes to this amendment that have been included below strikes a balance between accurate modeling and testing guidance and the best use of time and money to achieve the objective.

Proposed Change:

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 and documented 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.

 

Exception: Duct When all of the following conditions are met and documented, duct leakage to outside testing is not required, and 0 CFM@25 Pascals of leakage to outside duct leakage to outside may be assigned to the duct system in the rating software. 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 and documented to be contained inside the Infiltration Volume.

 

? The duct system is 100% fully ducted with flexible or hard ducting. 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 or equal to 0.15 3 air changes per hour or 0.24 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.

Comment #24

Page Number: 1
Comment Intent: Objection
Comment Type: Technical

Comment:

Duct testing as shown in RESNET approved energy model programs has no effect on HERS scores and minimal effect on annual energy bills when complete system is located in conditioned space (at least in my climate zone 1). A quick analysis on a typical 1800 sq. ft home with a IECC compliant infiltration of 5ACH50 and changing nothing except duct leakage numbers using Ekotrope version 2.2.3 shows the following:

TTL Leakage

LTO 

(1/2 TTL)

HERS

Annual Energy

Cost

0 0 55 3085
72 36 55 3086
145 73 55 3087
218 109 55 3088
363 182 55 3091


So even with a huge 20% of CFA total duct leakage, the HERS score did not change and the annual energy cost went up by $6.  And as others have pointed out, duct testing does add to the cost of ratings significantly. I would encourage a full analysis like I have done for a typical production home in each of the climate zones before making this testing mandatory when complete system is inside conditioned space.

The exceptions, as also pointed out by others, are very unrealistic. Even Energy Star v3 gives max air infiltration in ACH50 by climate zone rather than a blanket 0.15cfm50 / shell area. LEED Homes most stringent is at 0.23 cfm50 / shell for their compliance.

Since either duct test requires almost the same amount of time and since LTO requires a blower door that will already be installed, I think ALL duct testing should be excepted under certain conditions, not just LTO. The rationale has always been that total leakage in a system which is 100% located inside conditioned space, while not ideal, has little energy penalty which seems to be borne out at least in my climate zone. Sure a very leaky home will then have a bit more 'leakage to outside' but by dropping the infiltration from 5ACH50 to 3ACH50 in the same tests above, it dropped the HERS score to 54 and annual energy by $15

Please consider doing further research before requiring testing and leaving exeptions to testing ONLY for LTO at very unrealistic numbers.

Thank you.

Comment #25

Page Number: several comments
Paragraph / Figure / Table / Note: unable to cross-reference
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

1. Duct Testing Waiver At Final Rating

-- I believe this could be waived if all HVAC ducts are in conditioned space and fully visible at the final (such as the Unfinished Basement ceiling of a Ranch style home with all floor-mounted registers).  

~ This would also require all ductwork to be hard ducted (metal or flex), reasonably sealed and with no sections installed in any building cavities (such as a Utility Chase or 2nd Floor joist system).

-- If a Rough-In test was done, this data could be entered as Total Leakage but should be noted if testing was With or Without the Air Handler.

-- Also, the Rating software should be modified to register the Testing Waiver or to provide default Outdoors and Total Leakage data entries if Final tests are not done.

 

2. Mandatory Final Duct Testing

~ I believe Final Duct Tests should be mandatory whenever HVAC ducts in unconditioned spaces; not fully visible (as noted above) OR if any Building Cavities (such as joists & stud walls) are used as Return ducts.

~ My years of experience informs me that even hard metal ducts in Utility Chases can be damaged  during construct causing Code or Energy Star test failures.

~ Also Building Cavity Returns are still allowed by the 2009 IECC (here in Nebraska) and under certain modified 2012 IEEC codes (such as nearby Iowa.)  Some of my recent code-compliance Duct Tests in both states have produced leakage rates that fail the Total Leakage limits but are "saved" by meeting alternate Outdoor Leakage rates -- however, a scant few systems have suffered double failures. These high leakage rates can sometimes be found in houses that "passed" Rough-In code compliance tests.

 

3. Change in Manometer Recalibration Requirements

~  I strongly support the proposal to change the Mandatory one -ear recalibration period to one that allow a period of time deemed acceptable the testing device manufacturer.

~  It should also be acknowledged that Field Verifications of test equipment will be acceptable if performed and documented as prescribed by the manufacturer.

~  If this change is approved, it is unknown when this will be made retroactive for all recently calibrated equipment. (example: a factory calibration or field verification done in July 2017 would be valid until July 2019 if the manufacturer allows a 2 year interval).

~  Several years ago, The Energy Conservatory announced  they considered their Manometers reliable and guaranteed tcalibration for a 2 year period. At that time, aters could not take advantage of this extended warranty due to the current Guidelines limits.

~  In my ten years as a HERS Rater, I've seen the cost increase from $75 to $125 -- this adds to other ever increasing overhead costs for a one-person Rating business.

 

Proposed Change:

Sorry, unable to provide these references. Please refer to above comments.

Comment #26

Page Number: 1
Comment Intent: Objection
Comment Type: Technical

Comment:

I agree with the proposed logic and suggested modification proposed by EnergyLogic.

Proposed Change:

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.

Comment #27

Page Number: 1
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

The comments below are issued on behalf of the Standards Committee of the North East Home Energy Rating Alliance, which represents more than 350 Raters and 11 Providers from NJ to Maine.

Exceptions to duct-leakage to outside have been common and have been granted consistently for many years. The exceptions have been informed by and documented in the 2015 IECC, ENERGY STAR, and rating software. The proposed changes would require additional testing where not previously required and higher values for duct leakage to outside if the exception were taken. For consistency with respect to energy codes and incentive programs, we propose the following changes to this duct leakage test as follows:

Justification for the final change is if the builder and/or HVAC contractor has made a concerted effort to seal the air handling system, and the system is tested and meets the Air Tightness Standards stated above, for the purposes of the HERS Rating or ERI, the Leakage To Outside cannot exceed the total leakage. Therefore, the total leakage rate can be used for both total and leakage to outside. This is a conservative approach in that the HERS Index would tend to be higher (penalized) if the LTO were not measured separately at final. This also requires that no modifications to the duct system have been made between the rough-in test and the final inspection.

Proposed Change:

Duct leakage shall be tested and documented by an Approved Tester in accordance with requirements of Standard ANSI/RESNET/ICC 380.

Exception: When all of the following conditions are met and documented, duct leakage to outside testing is not required, and half of the measured duct shall be assigned to 0 cfm may be entered in the energy model for duct leakage to outside.  

  • 100% of the ductwork and air handler shall be visually verified and documented to be sealed and contained inside the Infiltration Volume. The verification may occur before final if, at time of final, the Rater can determine to a reasonable certainty that the duct system has not been modified to put it in non-compliance at final.
  • ?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 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 or equal to 0.15 0.3 CFM50 per square foot of enclosure area, when tested in accordance with requirements of tested in accordance with requirements of Standard ANSI/RESNET/ICC 380. The enclosure area is the sum of the areas of the surfaces that bound the Infiltration Volume.

Additionally, when tested in accordance with requirements of Standard ANSI/RESNET/ICC 380, Total duct leakage may be used in place of Leakage-To-Outside. If this Total leakage test is done at rough then the boots in unconditioned space must be visually inspected to be sealed to the flooring or sheetrock at final inspection.

Comment #28

Page Number: Page 1
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

Exceptions to duct-leakage to outside have been common and have been granted consistently for many years. The exceptions have been informed by and documented in the 2015 IECC, ENERGY STAR, and rating software. The proposed changes would require additional testing where not previously required and higher values for duct leakage to outside if the exception were taken. For consistency with respect to energy codes and incentive programs, we propose the following changes to this duct leakage test as follows:

Justification for the final change is if the builder and/or HVAC contractor has made a concerted effort to seal the air handling system, and the system is tested and meets the Air Tightness Standards stated above, for the purposes of the HERS Rating or ERI, the Leakage To Outside cannot exceed the total leakage. Therefore, the total leakage rate can be used for both total and leakage to outside. This is a conservative approach in that the HERS Index would tend to be higher (penalized) if the LTO were not measured separately at final. This also requires that no modifications to the duct system have been made between the rough-in test and the final inspection.

Proposed Change:

Duct leakage shall be tested and documented by an Approved Tester in accordance with requirements of Standard ANSI/RESNET/ICC 380.

Exception: When all of the following conditions are met and documented, duct leakage to outside testing is not required, and half of the measured duct shall be assigned to 0 cfm may be entered in the energy model for duct leakage to outside.  

  • 100% of the ductwork and air handler shall be visually verified and documented to be sealed and contained inside the Infiltration Volume. The verification may occur before final if, at time of final, the Rater can determine to a reasonable certainty that the duct system has not been modified to put it in non-compliance at final.
  • ?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 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 or equal to 0.15 0.3 CFM50 per square foot of enclosure area, when tested in accordance with requirements of tested in accordance with requirements of Standard ANSI/RESNET/ICC 380. The enclosure area is the sum of the areas of the surfaces that bound the Infiltration Volume.

Additionally, when tested in accordance with requirements of Standard ANSI/RESNET/ICC 380, half of the total duct leakage may be used in place of Leakage-To-Outside. If this Total leakage test is done at rough then the boots in unconditioned space must be visually inspected to be sealed to the flooring or sheetrock at final inspection.