Comment #1Amendment: Proposed Substantive Changes to MINHERS Addendum 27Page Number: 2Paragraph / Figure / Table / Note: 303.1Comment Intent: ObjectionComment Type: TechnicalComment: The infiltration portion of the HERS calculation is predicated on the Sherman-Grimsrud Infiltration Model, which is limited to dwelling units of 3 stories or less. Because of this limitation, the proposed extension of the MINHERS scope exceeds the range over which the infiltration portion of the HERS calculation is valid. Most probably, any simulation of dwelling units which occupy more than 3 stories of conditioned space will underpredict the energy consumption due to infiltration. The Rated Home will appear to perform better than the actual home does. Given this, any ratings generated under the proposed exceptions should be clearly marked as being less accurate than typical ratings. Proposed Change: 303.1 All RESNET Home Energy Ratings conducted in accordance with this Standard shall comply with the provisions of ANSI/RESNET 301-2014, “Standard for the Calculation and Labeling of the Energy Performance of Low-Rise Residential Buildings using the HERS Index.” Any Home Energy Rating issued under the following exceptions shall be clearly labeled as exceeding the technical limits of the infiltration portions of the energy model, and shall indicate the predicted energy consumption of the Rated Home is most probably understated.
The infiltration portion of the HERS calculation is predicated on the Sherman-Grimsrud Infiltration Model, which is limited to dwelling units of 3 stories or less.
Because of this limitation, the proposed extension of the MINHERS scope exceeds the range over which the infiltration portion of the HERS calculation is valid. Most probably, any simulation of dwelling units which occupy more than 3 stories of conditioned space will underpredict the energy consumption due to infiltration. The Rated Home will appear to perform better than the actual home does.
Given this, any ratings generated under the proposed exceptions should be clearly marked as being less accurate than typical ratings.
303.1 All RESNET Home Energy Ratings conducted in accordance with this Standard shall comply with the provisions of ANSI/RESNET 301-2014, “Standard for the Calculation and Labeling of the Energy Performance of Low-Rise Residential Buildings using the HERS Index.” Any Home Energy Rating issued under the following exceptions shall be clearly labeled as exceeding the technical limits of the infiltration portions of the energy model, and shall indicate the predicted energy consumption of the Rated Home is most probably understated.
Comment #2Amendment: Proposed Substantive Changes to MINHERS Addendum 27Page Number: AllParagraph / Figure / Table / Note: Entire addendumComment Intent: ObjectionComment Type: GeneralComment: The proposed change creates a muddy distinction between the HERS Index and the Energy Rating Index. How will should the software providers and the RESNET Registry create a clear difference between a HERS Index which is also an ERI, vs a HERS Index which is not an ERI? This is bound to create market confusion. Proposed Change: Do not proceed with this addendum until it includes clear guidance for software vendors and the RESNET Registry on how to clearly show which HERS results are also ERI results, and which are not!
The proposed change creates a muddy distinction between the HERS Index and the Energy Rating Index.
How will should the software providers and the RESNET Registry create a clear difference between a HERS Index which is also an ERI, vs a HERS Index which is not an ERI? This is bound to create market confusion.
Do not proceed with this addendum until it includes clear guidance for software vendors and the RESNET Registry on how to clearly show which HERS results are also ERI results, and which are not!
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