From 167168d2ae8531b34ecb26eb1f9ae209b21ef22c Mon Sep 17 00:00:00 2001 From: "github-actions[bot]" Date: Fri, 6 Mar 2026 19:54:30 +0000 Subject: [PATCH] spec: add psychrometric-basic specification Created from issue #4583 --- plots/psychrometric-basic/specification.md | 33 ++++++++++++++++++++ plots/psychrometric-basic/specification.yaml | 28 +++++++++++++++++ 2 files changed, 61 insertions(+) create mode 100644 plots/psychrometric-basic/specification.md create mode 100644 plots/psychrometric-basic/specification.yaml diff --git a/plots/psychrometric-basic/specification.md b/plots/psychrometric-basic/specification.md new file mode 100644 index 0000000000..f7632623a6 --- /dev/null +++ b/plots/psychrometric-basic/specification.md @@ -0,0 +1,33 @@ +# psychrometric-basic: Psychrometric Chart for HVAC + +## Description + +A psychrometric chart plots dry-bulb temperature against humidity ratio, overlaid with curves for relative humidity, wet-bulb temperature, enthalpy, and specific volume. It is the fundamental tool for HVAC system design and air conditioning process analysis. The chart reveals the thermodynamic properties of moist air at a glance, enabling engineers to trace heating, cooling, humidification, and dehumidification processes as paths on the diagram. + +## Applications + +- HVAC engineering: designing and analyzing air conditioning systems by tracing process paths (heating, cooling, mixing) on the chart +- Building science: evaluating indoor thermal comfort zones and identifying condensation risks +- Industrial process engineering: optimizing drying operations and clean room environmental control + +## Data + +- `dry_bulb_temp` (float) - Dry-bulb air temperature in degrees Celsius, x-axis primary variable +- `humidity_ratio` (float) - Mass of water vapor per mass of dry air in g/kg, y-axis primary variable +- `relative_humidity` (float[]) - Constant relative humidity curves from 10% to 100% in 10% increments +- `wet_bulb_temp` (float[]) - Diagonal lines of constant wet-bulb temperature +- `enthalpy` (float[]) - Oblique lines of constant enthalpy in kJ/kg +- `specific_volume` (float[]) - Lines of constant specific volume in m3/kg +- Size: derived from psychrometric equations over a dry-bulb range of -10 to 50 degrees Celsius +- Example: standard atmosphere (101.325 kPa) psychrometric properties computed from ASHRAE formulas + +## Notes + +- The saturation curve (100% RH) forms the upper boundary of the chart and should be visually prominent +- Relative humidity curves (10%-100%) should be drawn as smooth curves between the saturation line and x-axis +- Wet-bulb and enthalpy lines run diagonally from upper-left to lower-right +- Specific volume lines run at a slightly different diagonal angle +- Include at least one example HVAC process path (e.g., cooling and dehumidification) shown as an arrow or highlighted line segment between two state points +- A comfort zone region (approximately 20-26 C, 30-60% RH) should be highlighted as a shaded rectangle or polygon +- All property lines should be labeled directly on the chart, not just in a legend +- Use standard sea-level atmospheric pressure (101.325 kPa) for calculations diff --git a/plots/psychrometric-basic/specification.yaml b/plots/psychrometric-basic/specification.yaml new file mode 100644 index 0000000000..7cd6219425 --- /dev/null +++ b/plots/psychrometric-basic/specification.yaml @@ -0,0 +1,28 @@ +# Specification-level metadata for psychrometric-basic +# Auto-synced to PostgreSQL on push to main + +spec_id: psychrometric-basic +title: Psychrometric Chart for HVAC + +# Specification tracking +created: "2026-03-06T19:54:00Z" +updated: null +issue: 4583 +suggested: MarkusNeusinger + +# Classification tags (applies to all library implementations) +# See docs/reference/tagging-system.md for detailed guidelines +tags: + plot_type: + - line + - contour + data_type: + - numeric + - continuous + domain: + - engineering + - energy + features: + - advanced + - annotated + - multi