R-Value: MAX value is too small (Engine limited to R49)

[JdeLarbre218]

Attic added R cannot be more than 50

Attics with one inch of fiberglass batt @ R3.33/in = additional R56.67 to achieve R60

Recommend increasing value to at least 60

[fishbaugher]

This is the same basic problem as #40 (Hard vs soft range checks)

[eckmanwe]

Is "60" the recommended value for Unfinished Attics only, or are there other conditions to which this applies? Please Confirm.

[JdeLarbre218]

Finished Attic - 'Collar Beam', have the ability to be insulated to R60 in some cases also

[fishbaugher]

Here is another example of a range check issue. In v8.9 the soft range check allowed R values > 10 in insulation types:

[eckmanwe]

This latest comment is a different issue, and upon initial review the recommendation does not appear to align with DOE QA/QC goals.

Similarly, the highlighted condition appears to be a workaround to define a material by R-Value rather than R/in that the form suggests.

Please provide common use case(s) for such a workaround (define as R-Value rather than R/in) for consideration by the DOE WA Advisory Group.

[fishbaugher]

Bill, thanks for pointing that out. You are correct in that this is a data entry error in the original, not a problem with the available range in units of r/in

[fishbaugher]

The original range problem for attic R-Value remains.

[JdeLarbre218]

Additionally to Range Values for attic R-Values: IF using Blown Cellulose, one can add 16" of max depth to achieve R60, IF using Blown Fiberglass, 18" is needed but the MAX DEPTH is capped at 16"

Workaround to add R60 Blown Cellulose is to use 'max depth' field

same applies to 'Finished Attic - Collar Beam'

[fishbaugher]

So, you can override the max depth available, but still R49 is the maximum attic insulation measure supported by the NEAT 8.12 analysis engine.

To test, I made 18" available for max depth and changed the weather file to Duluth for maximum HDD. NEAT can only analyze a max of R49 for the attic.

[fishbaugher]

I double checked the current WAWeb engine and confirmed that v10 is limited to R49 as well.

Is this important enough to leave open as a possible NEAT engine enhancement just for this PY?

[joe-shade]

Is the engine limited to searching that R-value, or is the highest default value R49? The desktop version allows more than R-49 to be installed, but has the same default values.