Codes Address Aspirating Smoke Detection (application note)

Overview

Honeywell Analytics' one-page application note compares how three NFPA standards view aspirating smoke detection. Its first message is that aspirating systems are not mandated by code and the requirements are dictated by the authority having jurisdiction (AHJ), but that they must comply with the relevant code when used. The decision therefore belongs to the designer, yet once made the compliance conditions apply.

NFPA 72 requires reduced detector spacing in high air-movement areas. In NFPA 75 the base package is a sprinkler system, detection and alarm, portable extinguishers and EPO, with clean agent suppression as an add-on. For NFPA 76 the note restates the 200 ft2 per port/sensor rule and the 400 ft2 per port limit where both high and low levels are provided.

It is a vendor publication and, being one page, cites no clauses and has no formulae; it does not replace the source texts. Its value is in showing the conclusion of the three standards at a glance: the split between the mandatory base package and the optional advanced detection and agent. That split shows which items can be traded off when cost and redundancy are chosen.

Key points

1. Aspirating detection is not required by code; the AHJ dictates requirements.
2. NFPA 75 base package: sprinkler system, detection and alarm, portable extinguishers, EPO.
3. Clean agent is an optional add-on under NFPA 75.
4. NFPA 72 requires reduced detector spacing in high air-movement areas.
5. NFPA 76: max 200 ft2 per port/sensor; 400 ft2 per port where high and low levels are both used.

Using it in design

• In the fire module model the NFPA 75 base package as mandatory items and clean agent and VESDA as optional add-ons with cost.
• Apply the NFPA 72 high-airflow spacing reduction automatically when room air-change rate is high (for example above 8 ACH, configurable).
• Do not label aspirating detection as "required by code"; state that it depends on the AHJ.

Who should read it

Designers comparing fire detection options on cost and code compliance.

Related standards

• NFPA 72
• NFPA 75
• NFPA 76

Publication details

Authors

Honeywell Analytics

Publisher

Honeywell Analytics

Year

Year not stated

Document language

English

Source type

Manufacturer

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation