Direct Answer

The proposed 9 m detector spacing is equal to the stated maximum nominal spacing of 9 m. The source calculation reports 12 detectors for a 36 m × 24 m room and a 4.5 m wall clearance; final spacing and layout must be verified against the applicable standard and detector manufacturer instructions.

At a Glance

Room	36 m × 24 m
Ceiling	4.0 m; flat ceiling
Proposed / nominal spacing	9 m / 9 m
Source result	12 detectors; 4.5 m wall clearance

Technical Content

Smoke Detector Maximum Spacing Verification Calculation

1. Purpose

To verify whether the proposed spacing between point smoke detectors complies with applicable engineering standards and manufacturer installation recommendations, ensuring effective fire detection coverage while minimizing undetected areas.

2. Engineering Objective

Determine the maximum permissible spacing between point smoke detectors based on ceiling configuration, detector characteristics, and applicable fire protection standards.

3. Applicable Standards

NFPA 72 IS 2189 NBC India Part 4 EN 54 UL 268 Manufacturer Installation Manual

4. Design Inputs

5. Assumptions

Flat unobstructed ceiling, uniform height, nominal spacing permitted by manufacturer, no significant HVAC effects.

6. Formula(s)

1. A) S ≤ Sm B) Wc = S / 2

7. Variables Explained

S = Proposed spacing; Sm = Maximum permitted spacing; Wc = Wall clearance.

8. Step-by-Step Calculation

1. Verify 9 ≤ 9 (Complies). 2. Wall clearance = 9/2 = 4.5 m. 3. Detector grid: 4 rows × 3 columns = 12 detectors.

9. Worked Engineering Example

Room: 36 m × 24 m, Ceiling: 4 m, Detector spacing: 9 m. Required detectors = 12.

10. Engineering Output

Detector spacing: 9 m Wall clearance: 4.5 m Detector quantity: 12 Nos.

11. Design Considerations

Coordinate with HVAC, beams, lighting and manufacturer recommendations.

12. Common Design Mistakes

Ignoring obstructions, airflow, wall clearances and manufacturer limits.

13. Practical Site Notes

Verify reflected ceiling plans and maintain accessibility.

14. Limitations

Final layout must comply with applicable standards and manufacturer instructions.

15. Related Engineering Systems

FACP, ASD, LHD, BMS, Smoke Control.

16. Cross References

VEP-001, EC-001, Related FAQs and Engineering Diagrams.

17. SEO Meta Title

Smoke Detector Maximum Spacing Verification Calculation | EC-002

18. SEO Meta Description

Engineering method to verify smoke detector spacing with worked example.

19. URL Slug

ec-002-smoke-detector-maximum-spacing-verification

20. Keywords

Smoke Detector, NFPA72, IS2189, Detector Spacing, Fire Alarm Design, Engineering Calculation

21. AI Search Summary

Smoke detector spacing is verified by comparing the proposed spacing with the maximum permitted spacing and ensuring wall clearances and environmental conditions comply with standards.

Source Tables

Parameter	Symbol	Value	Unit
Room Length	L	36	m
Room Width	W	24	m
Ceiling Height	H	4.0	m
Proposed Detector Spacing	S	9	m
Maximum Nominal Spacing	Sm	9	m
Ceiling Type		Flat Ceiling	–
Detector Type		Addressable Photoelectric	–
Wall Clearance	Wc	4.5	m

Frequently Asked Questions

Does this calculation confirm final detector compliance?

No. It checks the proposed spacing against the nominal maximum stated in the source. Ceiling conditions, obstructions, airflow, manufacturer instructions and applicable requirements still need review.

How many detectors are stated in the example?

The source example states 12 detectors arranged as 4 rows × 3 columns.

SEO & Publishing Details

SEO title: Smoke Detector Maximum Spacing Verification Calculation | EC-002

Meta description: Engineering method to verify smoke detector spacing with a worked example.

URL slug: ec-002-smoke-detector-maximum-spacing-verification

Keywords: Smoke Detector; NFPA 72; IS 2189; Detector Spacing; Fire Alarm Design; Engineering Calculation