BSR/RESNET/ICC Standard 301-2014 Addendum C-201x PDS-01 Comments Submitted

The following comments have been submitted:

Comment #1

Page Number: all
Paragraph / Figure / Table / Note: all
Comment Intent: Not an Objection
Comment Type: General

Comment:

I agree with the proposed changes. I believe that the ventilation rate is too high and that it unnecessarily affects the energy efficiency of the building for no apparent reason.

Comment #2

Page Number: Table 4.2.2(1)
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

I agree 100% with the proposed amendment for several reasons, they are:

#1) The rates would now be more in line per IECC Code requirements as of 2012. There was starting to be a conflict between 'Building Code' ventilation requirements and those required where Resnet Standards applied. This should keep both regulating bodies running pretty much in parallel. Good for business and Consumers.

#2) To my knowledge, having 35 years of residential experience; Consumersstill show very little interest in the overall benefit to mechanical ventilation. They do insist that 'spot' ventilation systems function but are still showing little interest in Whole-House systems. In fact Builders & Consumers in my part of the Country are kicking back to increased rates which can lead to fewer choices in equipment (exhaust, HRV,ERV etc..)where they are participating in a Voluntary Program. The proposed rate reduction addresses this and shows that reliable feedback from the Industry leads to better decisions regarding mandatory items of any kind especially with respect to Voluntary Programs.

I notice that the Resnet web posting states that this amendment would 'REMOVE REFERENCE' to ASHRAE 62.2-2013. I hope this does not mean the entire document especially with respect to 'control' section 4.4 where it states: "Readily accessable override control must be provided to the occupant". The 2015 IMC Mechanical Ventilation M1507.3.2 System Control; also requires "The Whole House mechanical ventilation system shall be provided with controls that enable manual override". 

I would recommend that system  'Control' be addressed somewhere in the event all reference to ASHRAE is in fact removed.

Thank you for the opportunity to comment: Joe Nagan - Home Building Technology Services, LLC - Wisconsin

Comment #3

Page Number: Table 4.2.2(1)
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

I agree 100% with the proposed amendment for several reasons, they are:

#1) The rates would now be more in line per IECC Code requirements as of 2012. There was starting to be a conflict between 'Building Code' ventilation requirements and those required where Resnet Standards applied. This should keep both regulating bodies running pretty much in parallel. Good for business and Consumers.

#2) To my knowledge, having 35 years of residential experience; Consumersstill show very little interest in the overall benefit to mechanical ventilation. They do insist that 'spot' ventilation systems function but are still showing little interest in Whole-House systems. In fact Builders & Consumers in my part of the Country are kicking back to increased rates which can lead to fewer choices in equipment (exhaust, HRV,ERV etc..)where they are participating in a Voluntary Program. The proposed rate reduction addresses this and shows that reliable feedback from the Industry leads to better decisions regarding mandatory items of any kind especially with respect to Voluntary Programs.

I notice that the Resnet web posting states that this amendment would 'REMOVE REFERENCE' to ASHRAE 62.2-2013. I hope this does not mean the entire document especially with respect to 'control' section 4.4 where it states: "Readily accessable override control must be provided to the occupant". The 2015 IMC Mechanical Ventilation M1507.3.2 System Control; also requires "The Whole House mechanical ventilation system shall be provided with controls that enable manual override". 

I would recommend that system  'Control' be addressed somewhere in the event all reference to ASHRAE is in fact removed.

Thank you for the opportunity to comment: Joe Nagan - Home Building Technology Services, LLC - Wisconsin

Comment #4

Page Number: Addendum C-201x PDS-01
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Not an Objection
Comment Type: Editorial

Comment:

The proposed modification reduces the minimum Ventilation Rate in residential buildings from the ASHRAE 62.2 2013 formula back down to the previous 2009 Standard. This is a welcome move for two important reasons:

1. There is no credible scientific study for residential dwellings that provides the proof of a minimum ventilation threshold ACH number below which occupants will suffer a health hazard.

2. In Hot & Humid climates such as the Florida climate, and more especifically in my South Florida area, the excess ventilation will create dangerous indoor moisture control problems. That, in turn, will force the use of Energy-wasting dehumidification schemes which defeat the intent of the HERS rating and overall home energy savings.   

Comment #5

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

Comment:

This addendum is inappropriate for both technical and policy reasons.  RESNET 301 should focus on how to rate homes, which is it's TPS, and not what minimum acceptability criteria are.

ASHRAE Standard 62.2 is the ANSI designated standard for looking at residential ventilation and indoor air quality.   Unlike the 62.2 committee, the RESNET committee for 301 was not constituted to be balanced or even explicitly knowledgeable about such IAQ issues.  Creating a different, defacto, minimum standard is beyond the scope of 301 and conflicts with another ANSI standard--violating ANSI policy.

Passage of this addenum would encourage users of 301 to design homes that did not meet the minimum acceptable American National Standard for acceptable indoor air quality. This could expose the users (and RESNET) to liabiilty for any IAQ problems.

Passage of this addendum would disadvantage designs that did not meet minimum profesional standards of care by generating a lower score for those designs that are acceptable to RESNET but sub-standard to the industry.  Some say could be construed as restraint of trade.

If passed, this addendum could cause RESNET to be dropped as an acceptable compliance mechanism for many State and Federal programs.   Several states and relevant Federal agencies require the use of ASHRAE Standard 62.2 independent of RESNET and may drop the use  of 301, if the 301 uses substandard levels as their reference in their next iterations.  EnergyStar, for example, intends only to allow the current version of 62.2 in their next version and not allow the 2013 and earlier versions.

The reference house and minimum requirements for the rated home should be ASHRAE  62.2-2016.  (Previous versions are not supported by ASHRAE.)   The 2016 version is a superior choice for RESNET because it includes a "variable ventilation" option, which can be used to reduce the  energy consumption of providing meeting minimum ventilation requirements compared to the reference house.

Proposed Change:

1) Reject entire addendum.

2) Update use of ASHRAE 62.2-2013 to current version 62.2-2016

Comment #6

Page Number: 301-2014 ADDENDUM C-201X PDS-01
Paragraph / Figure / Table / Note: Table 4.2.2(1) and Section 4.3.3.2.5.
Comment Intent: Objection
Comment Type: Technical

Comment:

The Illinois Office of Energy & Recycling recommends disapproval of the proposed change on grounds that trade-offs between the levels of acceptable indoor air quality afforded by 62.2-2010 with those found in 62.2-2013 would lessen indoor air quality in favor of other “builder-selected” options.  We see the “trading-off” of indoor occupant health and safety provisions indisputable (i.e.., the uninformed homeowner must be guaranteed an acceptable level of indoor air quality, not at the expense of what a home builder deems detrimental to his/her pocketbook).  ASHRAE Standard 62.2 is the American National Standard that determines minimum ventilation for acceptable indoor air quality in low-rise residential buildings.   Moreover, the ICC International Residential Code (IRC) establishes ventilation for acceptable indoor air quality that would inherently conflict with the proposed change in reference.  Furthermore, homes built to either ASHRAE Standard 62.2 or ICC IRC will be disadvantaged in the market as they will be more susceptible to receiving lower HERS Indices or Energy Rating Indices merely for meeting minimum ventilation standards for human health in predominantly adopted and accepted engineering practices.  The Illinois Office of Energy & Recycling encourages the RESNET 300 Standards Committee to adopt the most recent edition of the ASHRAE Standard 62.2-2016.

Proposed Change:

Remain as written, without change.

Comment #7

Page Number: all
Comment Intent: Not an Objection
Comment Type: General

Comment:

I am in favor of the proposed amendment. Resnet Standards apply to Voluntary program activity and does not set (at this time) requirements for all new construction.

Building Codes are responsible for construction standards. With all due respect to the many folks who contribute to committees such as ASHRAE 62.2, why haven't the Model Codes adopted 62.2 for Whole-dwelling ventilation equirements? Having the Codes adopt 62.2 would impact all new homes not just those enrolled in a voluntary program.

Even 2015 IECC R403.6 references IRC/IMC with lower rates as proposed in this amendment.

It appears that the comments regarding this amendment are split into 2 camps; one in favor of higher rates (62.2) and one favoring lower rates, each camp with their own rational for their position.

Having the Building Codes adopt 62.2 could satisfy those in favor of higher rates, and actually impact MORE homes, while Resnet sets their own Program requirements for voluntary program activity.

Wouldn't this be a more practical solution?

Comment #8

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

Comment:

The ventillation of the refererence home should not change.  However, there should be options for selecting the ventilation requirement of the local jurisdiction.  Not all jurisdictions have adopted themost recent IRC and some have adopted separate ventilation requirements of ASHRAE 62.2 2010 (a few have adopted 2013, which Santa Fe has chosen not to for a variety of good sustainable building practice reasons.) 

Santa Fe New Mexico REQUIRES energy modeling for ALL NEW SINGLE FAMILY RESIDENCES.  At present all raters use RESNET software.  Should the ventilation rate in the reference home be different that what we require, without the option to select the rate we require, then we will no longer be able to accept RESNET software modeling for building permits. 

(Santa Fe currently requires compliance with ASHRAE 62.2 2010 ventilation rates).

Comment #9

Page Number: 2
Paragraph / Figure / Table / Note: Footnote (h)
Comment Intent: Objection
Comment Type: Technical

Comment:

Footnote (h) creates a perverse incentive within the Standard.  In effect, it discourages improvements in building energy efficiency (as well as indoor air quality) by rewarding natural infiltration above a specific cfm threshold: (0.02*CFA).  The idea for this footnote was clearly taken from the 2010 version of ASHRAE 62.2, but even in that version the reduced ventilation requirement was restricted to houses built prior to the application of that version of the standard.

More generally, the 2013 and 2016 versions of ASHRAE 62.2 are designed to explicitly address the concerns of ventilation in dwellings which are achieving notably low levels of energy loss via infiltration.  The 2010 version explicitly assumed infiltration was providing the (0.02*CFA) cfm referenced in this Footnote (h).  This assumption is no longer valid.

Given the energy efficiency goals implicit in ANSI/RESNET/ICC Std 301-2014, it seems more appropriate to reference the most current authority (ASHRAE 62.2-2016) for providing acceptable ventilation in very airtight dwellings.  Using a ventilation standard that is out of date by two code cycles is hard to defend.

Proposed Change:

At the least, strike the new Footnote (h) in its entirety. 

More generally, update ANSI/RESNET/ICC Std 301 to reference the current ASHRAE 62.2-2016 ventilation standard.

Comment #10

Page Number: All
Comment Intent: Not an Objection
Comment Type: General

Comment:

I feel that the current whole house ventilation systems are adequate as is.  I feel that they should remane the same and NOT be changed on January 1, 2017.  I am a rater testing and certifing new homes every day.  The current whole house ventilation requirements seem to be just right.  They provide plenty of ventilation, while not over-venting the home.  I fear that the proposed whole house ventilation system will over-ventilate in certain situations.

Thank you.

Sincerely,

Patrick Miller, Consultant

Comment #11

Page Number: All
Comment Intent: Not an Objection
Comment Type: General

Comment:

I have been a Rater since 1998, evaluated over 1600 homes and agree with your systems approach to testing and considering components in new and existing homes.

This ADDENDUM C-201X PDS-01 makes sense. It portrays to Builders and Contractors the validity of our Program by using the most recent scientific evidence from home investigations/assessments and applying common sense to gain our end results/benefits to the homeowner.

Thank you for your work and time.

Comment #12

Page Number: 1-3
Paragraph / Figure / Table / Note: 4.2.2
Comment Intent: Objection
Comment Type: Technical

Comment:

ASHRAE recommends disapproval of the proposed change in Addendum C-201x PDS-01.   ASHRAE recommends instead of making the changes proposed in this addendum that references to ANSI/ASHRAE Standard 62.2 in ANSI/RESNET/ICC Standard 301-2014 be updated to ANSI/ASHRAE Standard 62.2.-2016.

 

This proposal would result in indoor air quality in many new homes below what ASHRAE considers acceptable and should not be done. ASHRAE Standard 62.2 is the American National Standard that determines minimum ventilation for acceptable indoor air quality in residential buildings.  The “trading-off” of indoor occupant health and safety provisions for energy is inappropriate.  Furthermore, homes built to ASHRAE Standard 62.2 will be disadvantaged in the market as they will be more susceptible to receiving lower HERS Indices and/or Energy Rating Indices merely for meeting minimum ventilation standards for human health.

 

 

Proposed Change:

ASHRAE recommends instead of making the changes proposed in this addendum that references to ANSI/ASHRAE Standard 62.2 in ANSI/RESNET/ICC Standard 301-2014 be updated to ANSI/ASHRAE Standard 62.2.-2016

Comment #13

Page Number: 1
Paragraph / Figure / Table / Note: 301/4.2.2(1)
Comment Intent: Not an Objection
Comment Type: General

Comment:

I support the ammendment to revert the whole-house ventilation requirements to the ASHRE 62.2 - 2010 Whole house ventilation standards

Proposed Change:

Comment #14

Page Number: 1
Paragraph / Figure / Table / Note: 4.2.2
Comment Intent: Objection
Comment Type: General

Comment:

I agree with with the amendment. I'd like to see the ventilation requirements remain the same. The current ventilation requirements are more than adequate. Too much ventilation in the northern climates will over dry the houses during the winter months causing additional problems. There's Spot ventilation in every bathroom and the kitchen is also vented to the exterior. This is more than enough ventilation.

Comment #15

Page Number: 62.2
Comment Intent: Objection
Comment Type: General

Comment:

I have been testing ventilation on residential homes for twenty years.  I the beginning there was a significant need for testing requirements on the ventilation systems in both new and existing homes throughout Wisconsin.  I cannot count the number of air exchangers that have been installed with the dampers totally shut for up to ten years.  Also, there have been numerous occasions where, top of the line, exhaust only fans had a tested fan flow of zero.  I strongly believe in testing ventilation products, but the flow rates that are suggested in the new standard will dry out houses in Wisconsin.  I have reduced the moisture issues on the homes we have been hired to evaluate to zero.  We have no moisture issues until the wind chill is around -30 degrees.or less.  The builders we work with are completely satisfied with the service we provide, and have commented on the lack of moisture related issues they have been receiving.  I do not want to go to the other extreme and have to start dealing with overly dry homes.  There has been only two house that have complained with being too dry.  They both have installed large exhaust fans that are run more frequently.  Similar to your new proposal.  I strongly encourage to stay with 62.2 2010 to reduce the need to add another system to the HVAC(humidifier) to introduce more humidity into the air.

Proposed Change:

Remain with 62.2, but maybe add automated controls or a de-humidistat switch to make sure the system is being operated.

Comment #16

Page Number: All
Comment Intent: Not an Objection
Comment Type: General

Comment:

I agree 100% with proposed amendment for the following reasons:

1) The proposed ventilation requirements will be more in line with current state code requirements.

2) Today's consumers living in homes using ventilation rates similar to the rates in the amendment have been satisfied with the ability to control home humidity levels without experiencing home over-drying during the heating season and humidity over-loading during the air conditioning season.

3) Without the amendment, ventilation rates will be increased on January 1, 2017 to meet the ASHRAE 62.2-2013 formula.  This formula requires larger ventilation rates which will potentially increase heating and cooling loads in homes. 

Thank you for the opportunity to comment on the addendum to the standard.

 

Comment #17

Page Number: all
Comment Intent: Not an Objection
Comment Type: General

Comment:

I am in support of this amendment that will keep the present ventilation standard in place. I feel this way for a number of reasons:

1) The present ventilation requirements appear to be working: I am not aware of any house passed through our program (in Wisconsin) that has had an issue due to lack of ventilation. Some fans do have problems for a variety of reasond (that's why we test 'em) but once fixed they are adequate at the rates prescribed by the present formula. Where is the data that shows this issue needs to be addressed?

2) Requiring additional capacity will add complexity and cost. Most single fans meet the present requirment, even including for reasonable drops in flow rate due to duct losses. With substantially higher requirements, now there may have to be some additional "trickery" (wiring two fans together) or larger fans (many we are using are already the largest available).

3) Adding larger ventilation to one bathroom will result in complaints from customers, mostly due to the hurricane force winds blowing across their wet bodies as they dry off in the bathroom. Some fans, even though they have low sone ratings, will still be somewhat noisy due to being larger. This too will lead to complaints. 

4) Moisture issues are well understood in the building science community and we are rarely seeing problems with high humidity (except perhaps while the house is new and drying out). Very good attention to draingage and shell tightness now allows us to effectively control interior humidity. Additional ventilation will likely lead to excessive drying (= more complaints) or, when it's humid outside, an increase in the possibility for condensation as moist air is drawn in. The Ventilation should really be run for as short a time as possible at the lowest rate practicable.

5) Home performance is a hard enough sell already, forcing builders to change things they believe are already being done properly does not inspire confidence in efficiency programs. This seems like change for change's sake (or are there considerations being given to the more advanced ventilation equipment manufacturers here?)

 

Perhaps a modification to the standard should give credit for using a balanced approach rather than tempting builders to use a brute-force approach - which I suspect most of them will to save money. Not sure though how this could work as balanced venting won't necessarily lead to energy savings over exhaust only.

I believe that increasing the ventilation rate will cause builders to question what "we" know about  building performance and, perhaps, drop out of program participation. These changes seem rather arbitrary and should really be adopted only with very conslusive evidence that they are needed.

 

thank you.

Comment #18

Page Number: all
Comment Intent: Not an Objection
Comment Type: General

Comment:

I support this amendment. The ventilation provisions in RESNET are not "requirements" for the rated home. They set boundaries on the rated home to get HERS index "credit" for increasing air tightness; at the same time they set the reference home energy use for ventilation with both fan and space conditioning energy so that the rated home may get relative credit or penalty if its ventilation system is more or less efficient than the reference.

The establishment of a baseline for mechanical ventilation in the reference homea  and establishing limits on credit in the rated home for sealing, when such ventilation does not exist, should be based on current residential codes.  In general, the reference home in RESNET 301 is to be kept as consistent as possible, based on the 2006 IECC. But because whole-house ventilation requirements were not included in the 2006 IECC, some judgment previously had to be made regarding reference and rated home ventilation baselines, in order to ensure that ratied homes did not get undue "credit" relative to the reference home for sealing air leakage in the absence of reasonable whole-house ventilation. 

When the RESNET standards were first written, there was no residential whole-house ventilation requirement in the code, so ASHRAE 62-89 as it was commonly interpreted in the energy efficiency industry at the time made sense. When RESNET/ANSI 301 was published, using a reference home derived from the 2006 IECC, there was still no nationally recognized residential code requirement for whole-house ventilation; ASHRAE 62.2-2013 was a sensible choice at that time.

Now that the IRC has specific provisions for whole-house ventilation, it is the best path to use as a baseline for HERS ratings.Neither ASHRAE 62.2-13 nor -16 are code requirements except possibly in some limited jurisdictions. Both the 2015 IRC and by reference the 2015 IECC require whole-house mechanical ventilation explicitly.  The provisions of the 2015 IECC, because they have been adopted into the international code, also provides parity between HERS and the performance method of the I-codes going forward, which is also beneficial. 

Finally, the shift in calculation methodology for energy loads associated with ventilation is also an improvement.  These changes should be adopted as-is.

 

Proposed Change:

N/A

Comment #19

Page Number: 14,15, and 39
Paragraph / Figure / Table / Note: Table 4.2.2(1) and Table 4.4.2(1)
Comment Intent: Not an Objection
Comment Type: Technical

Comment:

The purpose of these edits are strictly to:

  1. Clarify the proposed language to ensure more consistent application of the standard.
  2. Extend the concept introduced in footnote i, for which the run-time fraction is automatically calculated for CFIS systems, to all ventilation system types. Standard 301 does not currently provide a procedure for verifying the run-time of a Whole-House Mechanical Ventilation System, yet requires Raters or equivalent parties to enter this input into rating software. This can produce inconsistent ERI ratings. The edits propose that the rating software use the Rater-verified Whole-House Mechanical Ventilation System rate (per Std, 380) to calculate the run-time fraction that would be required to ensure compliance with the relevant ventilation standard. In the future, if RESNET develops a procedure for verifying the run-time, then the standard can once again require that this parameter be verified by the Rater.
Proposed Change:

In the Building Component section for Air Exchange Rate:

For the Energy Rating Reference Home:

Specific Leakage Area (SLA)(d) = 0.00036(f) as supplemented by mechanical ventilation added in quadrature(gh) where necessary to bring the total combined air exchange rate to 0.30 ach and assuming no energy recovery

For the Rated Home:

Tested in accordance with requirements such as or equivalent to ANSI/RESNET/ICC Standard 380-2016

For a residences without a Whole-House Mechanical Ventilation Systems, the greater of 0.30 ach or the measured infiltration rate(e) but not less than 0.30 ach

For a residences with a Whole-House Mechanical Ventilation Systems, the  combination(g), (h) of the measured infiltration rate(e),(f) combined in quadrature(g) with the time-averaged measured(i) Whole-House Mechanical Ventilation System rate.

 The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.01 x CFA + 7.5 x (Nbr+1) cfm(h),(i)

To meet the definition of a Whole-House Mechanical Ventilation System, the measured(i) Whole-House Mechanical Ventilation System Rate shall meet or exceed 0.01 * CFA + 7.5 * (Nbr + 1), except under the conditions defined in Footnote j (j).

In the Building Component section for Whole-House Mechanical Ventilation System Fan Energy:

For the Energy Rating Reference Home:

None, except where a mechanical ventilation system is specified by the Rated Home, in which case:

Where Rated Home has supply only or exhaust-only Whole House Ventilation System:

0.35*fanCFM*8.76 kWh/y

Where Rated Home has balanced Whole-House Ventilation System without energy recovery:

0.70* fanCFM*8.76 kWh/y

Where Rated Home has balanced Whole-House Ventilation System with energy recovery: 1.00*fanCFM*8.76 kWh/y

And where fanCFM is calculated as 0.01 * CFA + 7.5 * (Nbr+1) cfm, except under the conditions defined in Footnote k (hk)

Footnotes:

(e) Tested envelope leakage The infiltration rate shall be determined measured and documented by an Approved Tester using the on-site inspection protocol as specified by requirements such as or equivalent to ANSI/RESNET/ICC Standard 380-2016 or equivalent.

(f) The Effective Annual Average Infiltration Rate (cfm) shall be determined in accordance with Section 4.1.2 of ASHRAE Standard 62.2-2013.

(g) The combined air exchange rate Effective Annual Average Infiltration Rate (cfm) shall be determined calculated as follows:

Qtot = Qinf + Qfan

Where:

  • Qtot = Combined air exchange rate (cfm)
  • Qinf = Effective Annual Infiltration Rate (cfm), calculated in accordance with Section 4.1.2 of ASHRAE Standard 62.2-2013 using the measured infiltration rate.
  • Qfan = Time-Averaged Whole-House Mechanical Ventilation System Rate = Measured Whole-House Mechanical Ventilation System Rate * Fractional On-Time
  • Fractional On-Time = [0.01 * CFA + 7.5 * (Nbr + 1)] / Measured Whole-House Mechanical Ventilation System Rate, not to exceed 1.0.

(gh) Either hourly calculations using the procedures given in the 2013 ASHRAE Handbook of Fundamentals (IP version), Chapter 16, page 16.25, Equation 51 using Shelter Class 4 or calculations yielding equivalent results shall be used to determine the energy loads resulting from the combined air exchange rate infiltration in combination with Whole-House Mechanical Ventilation systems.

(i) The Whole-House Mechanical Ventilation System rate shall be measured and documented by an Approved Tester using ANSI/RESNET/ICC Standard 380-2016 or equivalent.

(jh) Where the measured Effective Annual Average Infiltration Rate determined calculated in accordance with Section 4.1.2 of ASHRAE Standard 62.2-2013 using the measured infiltration rate exceeds 0.02*CFA cfm, the minimum time-averaged measured Whole-House Mechanical Ventilation System rate shall meet or exceed [0.01 * CFA + 7.5 * (Nbr + 1)] – 50% * (Effective Annual Average Infiltration Rate – 0.02 * CFA)be reduced by 50% of the difference between (0.02*CFA cfm and-the measured Effective Annual Average Infiltration Rate (cfm).

(k) Where the Effective Annual Average Infiltration Rate calculated in accordance with Section 4.1.2 of ASHRAE Standard 62.2-2013 using the measured infiltration rate exceeds 0.02*CFA cfm, fanCFM shall equal [0.01 * CFA + 7.5 * (Nbr + 1)] – 50% * (Effective Annual Average Infiltration Rate – 0.02 * CFA).

(i) Where Whole-House Mechanical Ventilation is provided by a Central Fan-Integrated System (CFIS), the measured outdoor air flow rate of the CFIS, as determined in accordance with ANSI/RESNET/ICC Standard 380-2016, shall be used to compute the necessary runtime fraction of the CFIS required to achieve the time-averaged Whole-House Mechanical Ventilation system rate.

Table 4.4.2(1) Minimum Rated Features

In the Minimum Rated Feature section for Whole-House Mechanical Ventilation Systems:

Equipment type, Whole-House Mechanical Ventilation System Rate measured using ANSI/RESNET/ICC Standard 380-2016 or equivalent,  daily run hours, and wattage (a source is the Certified Home Ventilating Products Directory available from the Heating and Ventilation Institute (HVI).

Comment #20

Page Number: 1-3
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

This proposed RESNET Standard change is an excellent example of the key rationale for the ASHRAE 62.2 committee to change the formula beginning with 62.2-13.

 

The change (and almost all of the debate over the CFM required by either standard) does not reflect that in code driven homes that will be built to the 2012 IECC and 2015 IECC; there is actually little difference between the required minimum actual fresh air CFM requirements of either standard.  (Philip Fairey has excellent data / tables etc. that demonstrate this fact).

 

The biggest impact is in the “Projected Rating” and the very little impact is in the “Confirmed Rating”. Most fear appears to come from … the impacts of too many CFM’s of bad (hot, humid, cold or dry) fresh air.

 

A hidden issue is that increased CFM from 62.2 – 2013 will increase the HERS Index of the projected rating … and the majority of homes in the RESNET Rater universe are Projected Ratings and are never confirmed.

 

The equation changes in Table 4.2.2(1) for Air exchange rate and Whole-House Mechanical Ventilation fan energy results in a less representative Energy Rating Reference Home given the large variety of homes that receive a HERS Index. 
ASHRAE 62.2-2010 where the revised ventilation equation of 0.01 x CFA + 7.5 x (Nbr+1) is drawn from] assumes an infiltration rate 0.02 CFM.sq.ft. or essentially 7 ACH50. 

 

Most homes that will be rated (going forward) will not be at 7 ACH50 and therefore the revised equation is Table 4.2.2(1) will not be accurate.  Existing homes can be upwards of 15-20 ACH50 range; while new Code-compliant homes which represent a higher percentage of HERS rated homes will be in the 3-5 ACH50 range.  ASHRAE 62.2-2013 accounts for this variety of actual conditions through the inclusion of the infiltration credit which replaced the old 0.02 CFM.sq.ft assumed infiltration rate. 

 

ASHRAE 62.2-2013 removed the infiltration credit that was half the excess above 0.02 CFM.sq.ft for good reasons. It is / was complex and (still is) not well understood. It is a poor assumption in many homes. Returning this assumption to the HERS Reference Home is a focus on the wrong issue. The real argument here is that 62.2-2013 is hard … and the definition of “hard” is that it is different and makes us have to do and understand different things.

Proposed Change:

Air Exchange Rate - Energy Rating Reference Home
Specific Leakage Area (SLA)(d) = 0.00036(f) as supplemented by mechanical ventilation added in quadrature(g) where necessary to bring the total air exchange rate to 0.30 ach and assuming no energy recovery and with energy loads calculated in quadrature (f), (g)

Air Exhange Rate - Rated Home
...For residences with Whole-House Mechanical Ventilation Systems, the measured infiltration rate(e),(f) combined in quadrature(g) with the time-averaged Whole-House Mechanical Ventilation System rate.,(f) which The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.030.01 x CFA + 7.5 x (Nbr+1) cfm(h),(i)  calculated using ASHRAE 62.2-2013 and with energy loads calculated in quadrature (g).

Whole-House Mechanical Ventilation fan energy - Energy Rating Reference Home
...And where fanCFM is calculated in accordance with Section 4.1.2 ASHRAE Standard 62.2-2013 as 0.01 x CFA + 7.5 x (Nbr+1) cfm(h) for a continuous Whole-House Ventilation System.

Comment #21

Page Number: 1-3
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

This battle and the raging torrent of emotion surrounding mechanical ventilation standards are great theater. I love the “Joe vs. Max” discussions / debates. In some Fresh Air seminars, I have called the 62.2 Committee meetings “a swashbuckler” for those who have intense interest and the proper vocabulary.

 What we are watching is a titanic battle between two superheroes that we admire and respect. By watching and listening this high level reality show, I have learned immense amounts. It is just like (sometimes better than) watching Batman and Superman battle it out … or perhaps it is Capitan America vs. Iron Man.

 But, I laugh at the (lack of) outcome.

 In reality, what we are battling about is which standard we want the industry to fail to deliver.

 The vast majority of current products and installation methods under deliver to any standard. (If you don’t believe … go test for yourself. I will cover a lot of bets … and make big money when the industry discovers and acts on performance failure).

 The issues would be more relevant and worth discussion if the industry cared about the actual (real world) results.  Since “field efforts” are simplistic and weak (at best), the outcome of this argument has exactly ZERO impact in the real world … because most of the participants will not deliver … to either standard. If we actually tested, used all of 62.2-2013 and put the outcome in a confirmed rating, the measured difference between the performance standards is negligible.   

RESNET should be a leader in ensuring that high performance homes are adequately ventilated.

 ASHRAE 62.2-2010 assumes that all homes have an infiltration rate of 0.02 CFM.sq.ft. or essentially 7 ACH50.  Homes are required to have an infiltration less than 7 ACH50 (i.e. all homes complaint with the 2015 IRC or ENERGY STAR) will therefore align with ASHRAE 62.2-2010 assumptions and as a result be supplied with less outdoor air than is needed.

Proposed Change:

Air Exchange Rate - Energy Rating Reference Home
Specific Leakage Area (SLA)(d) = 0.00036(f) as supplemented by mechanical ventilation added in quadrature(g) where necessary to bring the total air exchange rate to 0.30 ach and assuming no energy recovery and with energy loads calculated in quadrature (f), (g)

Air Exhange Rate - Rated Home
...For residences with Whole-House Mechanical Ventilation Systems, the measured infiltration rate(e),(f) combined in quadrature(g) with the time-averaged Whole-House Mechanical Ventilation System rate.,(f) which The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.030.01 x CFA + 7.5 x (Nbr+1) cfm(h),(i)  calculated using ASHRAE 62.2-2013 and with energy loads calculated in quadrature (g).

Whole-House Mechanical Ventilation fan energy - Energy Rating Reference Home
...And where fanCFM is calculated in accordance with Section 4.1.2 ASHRAE Standard 62.2-2013 as 0.01 x CFA + 7.5 x (Nbr+1) cfm(h) for a continuous Whole-House Ventilation System.

Comment #22

Page Number: 1-3
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

I do not know how to align the various 62.2 standards with code. If they are not the same … I have seen internet discussion about how this will be bad and mean that the ERI cannot be allowed by Code … et al.

 Perhaps.

 Probably not.

 There are plenty of smart code people … with no ax to grind either way … who can probably address this issue.

 Reverting to 62.2-2010 means that RESNET rated homes will not being in compliance with some other codes and standards that also seem important, like Title 24, ENERGY STAR and the DOE weatherization program. We should study what the IMC will be doing … as Code Books (like the bible) often incorporate thoughts that are contradictory in practice.

One alternative, RESNET could consider adopting ASHRAE 62.2 – 2016. This standard has improvements for existing homes, includes multifamily and high-rise dwellings, and allows for use of advanced ventilation controls that would be advantageous to high performance homes. 

Proposed Change:

Air Exchange Rate - Energy Rating Reference Home
Specific Leakage Area (SLA)(d) = 0.00036(f) as supplemented by mechanical ventilation added in quadrature(g) where necessary to bring the total air exchange rate to 0.30 ach and assuming no energy recovery and with energy loads calculated in quadrature (f), (g)

Air Exhange Rate - Rated Home
...For residences with Whole-House Mechanical Ventilation Systems, the measured infiltration rate(e),(f) combined in quadrature(g) with the time-averaged Whole-House Mechanical Ventilation System rate.,(f) which The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.030.01 x CFA + 7.5 x (Nbr+1) cfm(h),(i)  calculated using ASHRAE 62.2-2013 and with energy loads calculated in quadrature (g).

Whole-House Mechanical Ventilation fan energy - Energy Rating Reference Home
...And where fanCFM is calculated in accordance with Section 4.1.2 ASHRAE Standard 62.2-2016 2013 3as 0.01 x CFA + 7.5 x (Nbr+1) cfm(h) for a continuous Whole-House Ventilation System.

Comment #23

Page Number: 1-3
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

The ASHRAE 62.2 committee is the recognized committee for this IAQ standard. We should continue to let this “reality drama” continue to play out at ASHRAE and watch the outcome. This is the actual impact of democracy (multiple voices) and Free Enterprise (let the marketplace decide). I see no rationale (based on the total failure of real world testing, products, measurement tools) … to deliver any reasonable rational for overriding the ASHRAE committee.

 Let’s spend our time going forward and not back.

Proposed Change:

Air Exchange Rate - Energy Rating Reference Home
Specific Leakage Area (SLA)(d) = 0.00036(f) as supplemented by mechanical ventilation added in quadrature(g) where necessary to bring the total air exchange rate to 0.30 ach and assuming no energy recovery and with energy loads calculated in quadrature (f), (g)

Air Exhange Rate - Rated Home
...For residences with Whole-House Mechanical Ventilation Systems, the measured infiltration rate(e),(f) combined in quadrature(g) with the time-averaged Whole-House Mechanical Ventilation System rate.,(f) which The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.030.01 x CFA + 7.5 x (Nbr+1) cfm(h),(i)  calculated using ASHRAE 62.2-2013 and with energy loads calculated in quadrature (g).

Whole-House Mechanical Ventilation fan energy - Energy Rating Reference Home
...And where fanCFM is calculated in accordance with Section 4.1.2 ASHRAE Standard 62.2-2016 2013 3as 0.01 x CFA + 7.5 x (Nbr+1) cfm(h) for a continuous Whole-House Ventilation System.

Comment #24

Page Number: 1-3
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

Making the change to align with ASHRAE 62.2-2010 risks RESNET rated homes not being in compliance with other codes and standards.  For example, the state of California, EPA Energy Star, and DOE weatherization program (among others) list compliance with ASHRAE 62.2-2013. These will upgrade to 62.2-2016 in due course. The IMC is also likely to at least upgrade to 62.2-2013 in the near future. 
As an alternative, RESNET should consider adopting ASHRAE 62.2 - 2016 that has significant improvements for existing homes, includes multifamily and high-rise dwellings, and allows for use of advanced ventilation controls that would be advantageous to high performance homes. 

Proposed Change:

Air Exchange Rate - Energy Rating Reference Home
Specific Leakage Area (SLA)(d) = 0.00036(f) as supplemented by mechanical ventilation added in quadrature(g) where necessary to bring the total air exchange rate to 0.30 ach and assuming no energy recovery and with energy loads calculated in quadrature (f), (g)

Air Exhange Rate - Rated Home
...For residences with Whole-House Mechanical Ventilation Systems, the measured infiltration rate(e),(f) combined in quadrature(g) with the time-averaged Whole-House Mechanical Ventilation System rate.,(f) which The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.030.01 x CFA + 7.5 x (Nbr+1) cfm(h),(i)  calculated using ASHRAE 62.2-2013 and with energy loads calculated in quadrature (g).

Whole-House Mechanical Ventilation fan energy - Energy Rating Reference Home
...And where fanCFM is calculated in accordance with Section 4.1.2 ASHRAE Standard 62.2-2016 2013 3as 0.01 x CFA + 7.5 x (Nbr+1) cfm(h) for a continuous Whole-House Ventilation System.

Comment #25

Page Number: 1-3
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

The equation changes in Table 4.2.2(1) for Air exchange rate and Whole-House Mechanical Ventilation fan energy results in a less representative Energy Rating Reference Home given the large variety of homes that receive a HERS Index. 
ASHRAE 62.2-2010 [where the revised ventilation equation of 0.01 x CFA + 7.5 x (Nbr+1) is drawn from] assumes an infiltration rate 0.02 CFM.sq.ft. or essentially 7 ACH50.  Most homes that are rated are not at 7 ACH50 and therefore the revised equation is Table 4.2.2(1) is not accurate.  Existing homes can be upwards of 15-20 ACH50 range, while new Code-compliant homes which represent a higher percentge of HERS rated homes will be in the 3-5 ACH50 range.  ASHRAE 62.2-2013 accounts for this variety of actual conditions through the inclusion of the infiltration credit which replaced the old 0.02 CFM.sq.ft assumed infiltration rate.  ASHRAE 62.2-2013 removed the infiltration credit that was half the excess above 0.02 CFM.sq.ft for good reasons: mainly that it was complex and not well understood and was a poor assumption in many homes. Putting this out-dated assumption back into the HERS Reference Home is a mistake.
 

Proposed Change:

Air Exchange Rate - Energy Rating Reference Home
Specific Leakage Area (SLA)(d) = 0.00036(f) as supplemented by mechanical ventilation added in quadrature(g) where necessary to bring the total air exchange rate to 0.30 ach and assuming no energy recovery and with energy loads calculated in quadrature (f), (g)

Air Exhange Rate - Rated Home
...For residences with Whole-House Mechanical Ventilation Systems, the measured infiltration rate(e),(f) combined in quadrature(g) with the time-averaged Whole-House Mechanical Ventilation System rate.,(f) which The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.030.01 x CFA + 7.5 x (Nbr+1) cfm(h),(i)  calculated using ASHRAE 62.2-2013 and with energy loads calculated in quadrature (g).

Whole-House Mechanical Ventilation fan energy - Energy Rating Reference Home
...And where fanCFM is calculated in accordance with Section 4.1.2 ASHRAE Standard 62.2-2013 as 0.01 x CFA + 7.5 x (Nbr+1) cfm(h) for a continuous Whole-House Ventilation System.

Comment #26

Page Number: 1-3
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

RESNET should be a leader in ensuring that high performance homes are adequately ventilated and should not support this reversion to ASHRAE 62.2-2010 which is an outdated approach. ASHRAE 62.2-2010 assumes that all homes have an infiltration rate of 0.02 CFM.sq.ft. or essentially 7 ACH50.  Homes are required to have an infiltration less than 7 ACH50 (i.e. all homes complaint with the 2015 IRC or ENERGY STAR) will therefore align with ASHRAE 62.2-2010 assumptions and as a result be supplied with less outdoor air than is needed.

Proposed Change:

Air Exchange Rate - Energy Rating Reference Home
Specific Leakage Area (SLA)(d) = 0.00036(f) as supplemented by mechanical ventilation added in quadrature(g) where necessary to bring the total air exchange rate to 0.30 ach and assuming no energy recovery and with energy loads calculated in quadrature (f), (g)

Air Exhange Rate - Rated Home
...For residences with Whole-House Mechanical Ventilation Systems, the measured infiltration rate(e),(f) combined in quadrature(g) with the time-averaged Whole-House Mechanical Ventilation System rate.,(f) which The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.030.01 x CFA + 7.5 x (Nbr+1) cfm(h),(i)  calculated using ASHRAE 62.2-2013 and with energy loads calculated in quadrature (g).

Whole-House Mechanical Ventilation fan energy - Energy Rating Reference Home
...And where fanCFM is calculated in accordance with Section 4.1.2 ASHRAE Standard 62.2-2013 as 0.01 x CFA + 7.5 x (Nbr+1) cfm(h) for a continuous Whole-House Ventilation System.

Comment #27

Page Number: 1-3
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

 If a Rated Home with Whole-House Mechanical Ventilation System(s) does not comply with the statement in Table 4.2.2(1) "The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.01 x CFA + 7.5 x (Nbr+1)"  when verified in the field by  a HERS Rater or RFI what is the result?  Can the home still be issued a HERS Rating?

Comment #28

Page Number: 1-3
Paragraph / Figure / Table / Note: Table 4.2.2(1)
Comment Intent: Objection
Comment Type: General

Comment:

This debate of the mechanical ventilation rates being used to calculate the HERS Index is misplaced unless not meeting the set Whole-House Mechanical Ventilation  rate prevents a home receiving a Confirmed HERS Rating.  RESNET should focus the limited time and resources of Staff and the voluntary committees on actually implmenting real QA in the field such that Raters actually test mechanical ventilation flowrates (which the vast majority frankly do not).

Another better use of the liited resources of RESNET would be spent on training and outreach such that Whole-House Mechanical Ventilation Systems were 1) being Cx correctly by installers and 2) being maintained over-time.  Even when Raters do their very best and enforce actual compliance with the prescribed ASHRAE 62.2 airflow rates, these measured values are only a snapshot in time.  1-year, 6-months, 2-weeks, down the line these systems will often not be performing to specification due to contractor and home-owner intervention.

Proposed Change:

Air Exchange Rate - Energy Rating Reference Home
Specific Leakage Area (SLA)(d) = 0.00036(f) as supplemented by mechanical ventilation added in quadrature(g) where necessary to bring the total air exchange rate to 0.30 ach and assuming no energy recovery and with energy loads calculated in quadrature (f), (g)

Air Exhange Rate - Rated Home
...For residences with Whole-House Mechanical Ventilation Systems, the measured infiltration rate(e),(f) combined in quadrature(g) with the time-averaged Whole-House Mechanical Ventilation System rate.,(f) which The time-averaged Whole-House Mechanical Ventilation System rate shall not be less than 0.030.01 x CFA + 7.5 x (Nbr+1) cfm(h),(i)  calculated using ASHRAE 62.2-2013 and with energy loads calculated in quadrature (g).

Whole-House Mechanical Ventilation fan energy - Energy Rating Reference Home
...And where fanCFM is calculated in accordance with Section 4.1.2 ASHRAE Standard 62.2-2013 as 0.01 x CFA + 7.5 x (Nbr+1) cfm(h) for a continuous Whole-House Ventilation System.