Applying NFPA 75 in data centers

Overview

In this 2016 article in Consulting-Specifying Engineer, Mark Jason Aaby explains the scope and structure of NFPA 75 (2013 edition) and how its risk-assessment basis, construction and fire protection chapters apply to IT equipment rooms. The article also summarises the key changes in the 2017 edition: an applicability decision tree, prescriptive, risk-based and performance-based approaches, and new combustibility definitions.

The article stresses that NFPA 75 is an occupancy standard that says what is needed, while installation standards such as NFPA 13 say how. On construction, IT equipment rooms must be separated from other occupancies by at least 1-hour fire-resistance-rated construction, with 3/4-hour rated doors. Ducts and transfer openings through the separation need automatic fire and smoke dampers.

On fire protection, an IT equipment area in a sprinklered building must itself be sprinklered (Section 8.1). Under 8.4.2.1 of the 2013 edition, power to electronic equipment must be disconnected when a gaseous total-flooding system discharges, unless the risk assessment shows that continuous power is needed.

The 2017 edition allows prescriptive, risk-based or performance-based approaches, yet federal owners (VA, DoD, GSA) often demand full prescriptive compliance. As a limitation, this is an expert article and does not replace the standard; the applicable edition and local regulations govern.

Key points

1. IT equipment rooms must be separated from other occupancies by at least 1-hour fire-resistance-rated construction.
2. Doors in the separation must be 3/4-hour rated.
3. Ducts and transfer openings through the separation need automatic fire and smoke dampers.
4. An IT equipment area in a sprinklered building must itself be sprinklered (Section 8.1).
5. 2013 edition 8.4.2.1: power to electronic equipment must be disconnected on gaseous total-flooding discharge unless the risk assessment shows continuous power is needed.
6. The 2017 edition allows prescriptive, risk-based or performance-based approaches.
7. Federal owners (VA, DoD, GSA) often demand full prescriptive compliance.
8. NFPA 75 says what is needed; standards such as NFPA 13 say how.

Using it in design

• Define the IT room default as 1-hour separation, 3/4-hour doors and fire and smoke dampers at penetrations.
• Apply the sprinkler requirement to the IT area when the building is sprinklered.
• Build an emergency power-off (EPO) interlock with clean-agent discharge that a documented risk assessment can override.
• Let the user choose the NFPA 75 edition.

Who should read it

Engineers designing data centre fire protection and reviewers checking fire-code compliance.

Related standards

• NFPA 75
• NFPA 13
• NFPA 101
• NFPA 5000

Publication details

Authors

Mark Jason Aaby

Publisher

Consulting-Specifying Engineer

Year

2016

Document language

English

Source type

Expert / community

Access

Free to read

Licence

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

Citation