HVAC & Mechanical Reference Charts
Duct sizing, airflow, static pressure, and sheet-metal look-up tables.
Electrical
25 CHARTSConductor, conduit, and grounding look-up charts for sizing and code checks.
CONDUCTORS & AMPACITY
- AMPWire Ampacity ChartCu & Al ampacity at 60 / 75 / 90°C by size.NEC 310.16
- ×0.8Ampacity Correction & Adjustment FactorsAmbient & bundling derate multipliers.NEC 310.15(B)(1) & 310.15(C)(1)
- DIMWire Dimensions ChartDiameter & area by insulation type and size.NEC Chapter 9, Table 5
- Ω/kftWire Resistance ChartDC resistance & stranding by AWG / kcmil.NEC Chapter 9, Table 8
CONDUIT, RACEWAY & TRAY
- FILLConduit Size & Fill ChartUsable fill area by trade size, EMT to PVC.NEC Chapter 9, Tables 1 & 4
- LBConduit Bodies ChartLB, LL, LR, T & X decoded, with form profiles.NEC 314.16(C)
- CTFCable Tray Fill ChartAllowable tray fill by width, ladder & solid.NEC 392.22
- MAXTHHN Conduit Wire Capacity ChartSOONMax THHN counts per conduit type and size.NEC Chapter 9, Tables 1, 4 & 5
GROUNDING & BONDING
- GNDGround Wire Size ChartMinimum EGC size by breaker or fuse rating.NEC 250.122
- GECGrounding Electrode Conductor ChartGEC size from the service-entrance conductor.NEC 250.66
- MBJBonding Jumper Size ChartMBJ / SSBJ & grounded conductor by supply size.NEC 250.102(C)(1)
- TRAYCable Tray Grounding ChartTray metal area to serve as the EGC, by OCPD.NEC 392.60(A)
MOTORS & TRANSFORMERS
MOTOR CIRCUITS & STARTERS
- SZ 1NEMA Starter Size ChartSizes 00–9: max HP per voltage, plus amps.NEMA ICS 2
- 175%Motor Circuit Protection ChartMax fuse & breaker % of FLA, plus overloads.NEC 430.52 / 430.32
- MTRMotor Circuit Data ChartWire, fuse, breaker, starter & switch per HP.NEC 430 / NEMA ICS 2
- AC-3IEC vs NEMA Starter ChartAC-1–AC-4 duties and the NEMA trade-offs.IEC 60947-4-1
DISCONNECTS & FUSES
ENCLOSURES & RECEPTACLES
Plumbing
11 CHARTSFixture units, drainage sizing, and pipe look-up tables — IPC and UPC labeled.
DRAINAGE, WASTE & VENT
- DFUDrainage Fixture Unit (DFU) ChartDFU values per fixture, IPC & UPC side by side.IPC 709.1 / UPC 702.1
- DRNDrain Pipe Size ChartDrain & building-drain size from total DFU.IPC 710.1 / UPC 703.2
- BLDGBuilding Drain & Sewer Capacity ChartMax DFU on building drain & sewer, by slope.IPC 710.1(1) / UPC 703.2
- VENTVent Pipe Size ChartVent size from DFU and developed length.IPC 906.1 / UPC 703.2
- SLPDrain Pipe Slope ChartMinimum grade per pipe size, IPC & UPC.IPC 704.1 / UPC 708.1
- TRAPFixture Trap Size ChartMin trap & trap-arm size per fixture, IPC & UPC.IPC 709.1 / UPC 702.1
WATER SUPPLY SIZING
- WSFUWater Supply Fixture Unit (WSFU) ChartWSFU per fixture, with GPM demand conversion.IPC E103.3 / UPC 610
- GPMWSFU to GPM Conversion ChartDesign GPM from total WSFU, both system types.IPC E103.3(3)
- WTRWater Pipe Sizing ChartSupply pipe & meter size from WSFU and length.UPC 610.4 / IPC 604.3
- FLOWFixture Water Demand ChartMax GPM & GPF per fixture, code & WaterSense.IPC 604.4 / EPAct 1992
FUEL GAS & GREASE
- GASNatural Gas Pipe Sizing ChartPipe size from BTU load and longest run.NFPA 54 / IFGC 402
- FOGGrease Interceptor Sizing ChartSOONInterceptor size from fixture flow & retention.IPC 1003 / UPC 1014
HVAC & Mechanical
10 CHARTSDuct sizing, airflow, static pressure, and sheet-metal look-up tables.
DUCT SIZING & AIRFLOW
- CFMDuct Sizing ChartCFM per round duct size at design friction rates.ASHRAE Fundamentals
- DeRectangular to Round Duct Conversion ChartEqual-friction rect ↔ round duct equivalents.ASHRAE Fundamentals
- ΔPDuct Friction Loss ChartLoss per 100 ft by CFM and duct diameter.Darcy-Weisbach (computed)
- FLEXFlex Duct CFM ChartTaut flex vs rigid CFM, plus the slack penalty.LBNL / ADC / UL 181
- FPMAir Velocity ChartRecommended FPM for ducts, grilles & coils.ASHRAE / ACCA lineage
LOAD & SYSTEM RULES
ABOUT THESE CHARTS
These charts cover the look-ups sheet-metal and mechanical contractors make while sizing air systems: round duct CFM capacity at design friction rates, rectangular-to-round equivalents per the ASHRAE equal-friction method, friction loss per 100 feet, lab-measured flex duct capacity with the compression penalty, recommended air velocities, component static-pressure allowances, the CFM-per-ton and square-feet-per-ton rules, sheet metal gauge and weight, and the code minimums for duct wall thickness and hanger support.
HVAC authority is fragmented — ASHRAE, ACCA, SMACNA, the IMC/IRC, and laboratory research each govern different tables — so every chart states its source and basis. Computed charts state their physics (Darcy-Weisbach at standard air, galvanized roughness); guidance charts state their lineage and publish ranges rather than inventing consensus. Verify against the mechanical code, the SMACNA edition your spec cites, and the equipment data plate.
When the answer needs computing instead of looking up — CFM for a specific space, duct size for a specific airflow and friction rate, a full static budget — each chart links to the matching NORDIX calculator. More mechanical tables (refrigerant P-T charts, line sizing, ventilation rates) are on the roadmap.
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