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Adds (then zeroes) door PSI-factors for NECBs #1734

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@brgix brgix commented Apr 25, 2024

Pull request overview

The initial implementation of TBD within BTAP (to support NECBs) applied the same fenestration interface PSI factors (W/K per linear meter) to opaque door edges. In a nutshell, 3.1.1.7. 1) of NECBs 2017 & 2020 require Ut calculations include PSI-factors from interface details (or "junctions") around "glazing assemblies", which would include OpenStudio subsurface types:

  • "FixedWindow"
  • "OperableWindow"
  • "Skylight"
  • "TubularDaylightDome"
  • "TubularDaylightDiffuser"
  • "GlassDoor".

Interface details around (opaque) "Door" and "OverheadDoor" subsurfaces would have to be excluded from BTAP's NECB 2017 and NECB2020 rulesets, as they are not included in 3.1.1.7. 1).

This came up when adding the new ASHRAE 90.1 2022 thermal bridging PSI-factor sets to TBD: ASHRAE 90.1 2022 clearly states the need to factor PSI-factors around vertical fenestration (a defined term), although it remains unclear what to do around skylights and opaque doors (see Q3 in this UnmetHours post). TBD now provides an extended thermal bridge type list, including:

  • :fenestration
  • :door
  • :skylight

... and related:

  • :balcony
  • :balconysill
  • :balconydoorsill

Solution:

  • extend (and test) revised list of thermal bridge types here, to cover all possible thermal bridge types (i.e. edge types).
  • assign (0 W/K per linear meter) to all opaque door related edge types

@brgix brgix requested a review from phylroy April 25, 2024 13:18
@brgix brgix self-assigned this Apr 25, 2024
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