The method
Before using the result
- Steady one-dimensional series conduction. User-supplied properties and film resistances; thermal bridges, air leakage and moisture effects are excluded.
Worked examples
These original training examples illustrate the method for Architect Registration Examination (ARE) - United States. Use the matching “Load example” button above to explore a variation; example values are not equipment settings or prescribed criteria.
1. Worked example
Build a wall thermal resistance from documented layer properties and surface films. Keep one-dimensional assembly performance separate from thermal bridging.
- Inside surface resistance (m²·K/W)
- 0.13
- Outside surface resistance (m²·K/W)
- 0.04
Supplied wall layers
| Layer | Thickness (mm) | Conductivity (W/m·K) |
|---|---|---|
| Example insulation | 100 | 0.04 |
| Example masonry | 100 | 0.8 |
- Rtotal = 0.13 + Σ(thickness/conductivity) + 0.04 = 2.795 m²·K/W.
- U = 1 / 2.795 W/m²·K.
- Total resistance: 2.795 m²·K/W
- U-value: 0.3577818 W/m²·K
2. Comparison example
Compare a different supplied condition using the same method. For Archi Conquer, the important check is that the input meaning, units and method assumptions still match the problem.
- Inside surface resistance (m²·K/W)
- 0.13
- Outside surface resistance (m²·K/W)
- 0.04
Supplied wall layers
| Layer | Thickness (mm) | Conductivity (W/m·K) |
|---|---|---|
| Example insulation | 150 | 0.04 |
| Example masonry | 100 | 0.8 |
- Rtotal = 0.13 + Σ(thickness/conductivity) + 0.04 = 4.045 m²·K/W.
- U = 1 / 4.045 W/m²·K.
- Total resistance: 4.045 m²·K/W
- U-value: 0.2472188 W/m²·K
Check your understanding
1. Which relationship is used?
Layer R = thickness/conductivity; total R = Rinside + ΣRlayers + Routside; U = 1/Rtotal.
2. Which assumption should you check first?
Steady one-dimensional series conduction. User-supplied properties and film resistances; thermal bridges, air leakage and moisture effects are excluded.
3. How should you verify a different unit system?
Convert every input to the displayed calculation units first. Equivalent physical inputs must give equivalent results; a unit label alone does not convert a number.
Continue with the matching exam topic
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