Engineering Methodology, Physical Constants & Standards
Technical documentation on the equations, safety factors and national/international codes applied across UnlimitCalc.
1. Electrotechnical Constants & Standards (Block 1)
- Electrolytic Copper Resistivity at 20 °C (ρ): 0.017241 Ω·mm²/m (100% IACS conductivity = 58 MS/m).
- Aluminum Resistivity at 20 °C (ρ): 0.028264 Ω·mm²/m (conductivity = 35.38 MS/m).
- Applicable Codes: NFPA 70 (National Electrical Code — NEC Table 310.16 and Art. 210.19/240), ASTM B258 for AWG wire geometry, and IEC 60364 / BS 7671.
2. Thermodynamics, HVAC & Fluid Mechanics (Block 2)
- Specific Heat of Water: 4,186 J/(kg·K), equivalent to 1.163 Wh/(liter·°C).
- Cooling & Heating Conversions: 1 kW = 3,412.14 BTU/h = 860 frigories/h (1 Ton = 12,000 BTU/h).
- Applicable Standards: ASHRAE Fundamentals & 62.1/62.2, EN 442 (radiator ΔT exponent n = 1.30), and EN 14825 (seasonal SCOP).
3. Civil Engineering & Construction Yields (Block 3)
- Drywall & Framing (ASTM C840 / EN 520): 400 mm (16") and 600 mm (24") stud spacing with a 7% sheet waste factor.
- Mortars, Screeds & Accessibility (ACI 318 / ADA / IBC): Dry bulk density ratios (16–22 kg/m²·cm) and ADA ramp slope verification (1:12 max).