ASHRAE floor area - not editable

[BrianaParrBaker]

Total conditioned floor area and the floor area used in the ASHRAE calc are not always the same. We need the ability to change the sq ft in the ASHRAE tab to not always be the same as the total sq ft.

[JdeLarbre218]

Agreed

[RandyRollie]

Also agree

[fishbaugher]

In v8.x these two floor areas are independent inputs.

[eckmanwe]

The floor area inputs are linked per testing and feedback from users and DOE. I do not imagine that the WA Advisory Group would agree to unlink those datapoints without clear and common use cases/illustrations.
As such, please provide multiple single-family and manufactured housing use cases where the values are different. Please include all appropriate rationale underlying the differences.

Please note, whenever doing comparisons to WAv8, we must use the last publicly released version, WAv8.9.

[BrianaParrBaker]

From the ASHRAE 62.2-2016 standard: All enclosed above- and below-grade finished areas suitable for year-round use as defined in ANSI Standard Z765. Include basements, or parts thereof, only if they are finished in a manner similar to the rest of the dwelling.

For 62.2 2016, any conditioned but unfinished areas of a basement are subtracted from the total floor area for the ASHRAE floor area. This can apply to entire basements if they do not have wall or floor coverings, or to unfinished sections of the basement such as a mechanical room or laundry room.

I see this was changed in an addendum to the 2019 standard to included unfinished below grade occupiable spaces. ().

However, I see in the 2020 draft of the ANSI Z765-2020 standard, it defines finished area as "An enclosed area in a house that is suitable for year-round use based upon its geographic region, embodying walls, floors, and ceilings that are similar to the rest of the house." I can't see the final standard without purchasing, but that's what both the 2/7/20 and 9/28/20 drafts say.

This issue does not apply to manufactured housing because they do not have below-grade occupiable spaces.

[eckmanwe]

Thank you Briana for the thoughtful notes.

There is no preclusion within WAweb from aligning the "Floor Area" input on the Audit form the ASHRAE definition. We heard from the DOE Tech POs about the significant inconsistencies and errors, and it was at DOE direction to link the data points. This said, we recommend discussing with your DOE Tech PO.

For reference, the Floor Area on the Audit Form is used for reporting, duct area estimation, and as a sanity check against the input Attic and Floor areas. So long as the ASHRAE definition floor area is within a reasonable margin (no less than 50% of either the total input Attic or Foundation/Floor areas) you will not see an error, nor have the run halted. Similarly, the default duct area calculations can be quickly overwritten if they are not valid.

At current, I cannot generate a reasonably conceivable where the ASHRAE definition floor area would be less than 50% of the total floor area entered on the Foundations form or total attic area entered on the Unfished and Finished Attic forms.

As such, it seems that the only limitation here is the choice to define these "Floor Area" inputs differently. From our standpoint, (and as noted above) we see no preclusion from using the same definition for Floor Area in both locations, and have reviewed the same with members of the DOE Tech Team.