poka.sh

 Docs

DDY

Generated by scripts/gen-format-pages.py from docs/data/format-metadata/, FILE_FORMATS.csv and docs/formats-master.csv. Do not edit by hand: change the source, then run the script.

EnergyPlus DDY Preview.

At a glance
Original creator EnergyPlus (U.S. Department of Energy)
Purpose Design day conditions for a weather location: the site and the extreme heating and cooling days a building model is sized against, in IDF syntax.
Extensions .ddy
Poka parser poka-ddy
Viewer poka-table-viewer
Depth tier Parser with a shared viewer (see Depth tiers)
Breadth tier B2 Broad (see Breadth tiers)

How much Poka reads

B2 Broad. The common content of the current and the common older versions is decoded. Some named features or versions are not, and are listed.

Confidence: high (the reviewer read the code and a test that proves the claim). Basis: Reviewed 2026-10-16: parsers/poka-ddy/src/lib.rs and unit tests, tests/samples.rs; corpus GBR_London.Gatwick IWEC, USA_CO_Golden and USA_IL_Chicago-OHare TMY3 .ddy files (each has 1 Site:Location, 1 DaylightSavingTime object, 18 design days). Covers Site:Location, SizingPeriod:DesignDay and the leading provenance comments.

What Poka does not read

  • Location time zone is not shown (header has name, latitude, longitude and elevation only)
  • The data-source and provenance comments at the top of the file are parsed but never displayed
  • Per design day: dry-bulb range modifier type and schedule, daily wet-bulb range, rain, snow-on-ground and daylight-saving indicators, and beam/diffuse solar schedules are not in the table
  • Humidity is shown only as the single value at maximum dry-bulb
  • RunPeriodControl:DaylightSavingTime dates are not shown (the summary only counts them as other objects)

Background

A .ddy ships with an EnergyPlus weather file (.epw) and holds the ASHRAE design conditions for that location as Site:Location and SizingPeriod:DesignDay objects. Unlike a general IDF it always carries the "!- Field Name" comments. Poka shows the location and one row per design day with a selection of its conditions (about a third of the fields).

Versions

Version Identifier Poka Note
EnergyPlus DDY Read

Libraries

Libraries Poka uses or has assessed for this format, with the status, licence and language the registry records.

Sources