HVAC Psychrometric Chart Practice Questions
Fire Protection - Ordinary Hazard III (Offices)
Ordinary Hazard Group III (Offices) - Quick Reference
Key Parameters:
- Occupancy: Offices (moderate combustibles – paper, furniture)
- Design Density: 5 L/min/m² (5 mm/min)
- AMAO: 216 m²
- Minimum Water Demand: 1,080 L/min (5 × 216)
Comparison Table
| Hazard Class |
Fire Load |
Density (L/min/m²) |
AMAO (m²) |
| Light Hazard |
Low |
2.25–4.5 |
84–150 |
| Ordinary Hazard III |
Medium |
5–7.5 |
216 |
| Extra Hazard |
High |
7.5–15+ |
260–360 |
Recommendations
- Use quick-response sprinklers for faster activation.
- Ensure water supply ≥ 1,080 L/min (verify hydraulic calculations).
- Follow NFPA 13 or local codes for spacing (max ~3.7 m between sprinklers).
- Conduct regular fire risk assessments to confirm hazard class.
Note: Adjust if combustible load exceeds typical office materials (e.g., archives = higher hazard).