July 26, 2026 — Air Flow live roles, Pressure bridge & SA/RA
Path: _pwa-build/ · July 26, 2026 (site v1.0.34) · SW cache v86
Shipped in this commit
- Air Flow (step 1): selected / previous / dynamic roles; blank inputs (no placeholders); live solve of the third value; edit highlighted output to rotate roles and cross-check. Removed shared Calculate button (CLR STEP / CLR ALL remain).
- Pressure (step 2): two always-visible calculators — SP / TP / VP and CFM / FPM / Area (no formula dropdown). Middle VP↔FPM UI removed; physics kept as a bridge.
- Bridge:
FPM = 4005 × √|VP| links the two blocks. Change either side and the other updates when enough values are set (one hop per edit; focused field never overwritten).
- Area: duct area entered in sq.in.;
CFM = FPM × (sq.in. ÷ 144).
- SA | RA toggle: bottom of SP/TP/VP block. Supply expects positive SP/TP; return expects negative. No auto-negate on switch. Zero is not a valid input on pressure/flow fields.
- Temp Split / Fan Laws: live recompute on input so they still work without Calculate.
- Help:
airflow-pressure.htm documents bridge, SA/RA, roles; helpindex.htm keywords/hint; airflow-sensible.htm live roles note.
Key files
app/tools/aircalc.htm — markup, SA/RA placement, dynamic-field styling (light/dark amber)js/airflow-calc.js — role engines, bridge, validationapp/help/airflow-pressure.htm, app/help/helpindex.htm, app/help/airflow-sensible.htmapp/sw.js — phvac-app-v86
Math (verified)
BTU = CFM × 1.08 × ΔTVP = TP − SP (and rearrangements)FPM = 4005 × √|VP|CFM = FPM × (Area_in² / 144)
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