For

Nitrogen Gas Fire Suppression System

Noise Reduction Nozzle
To protect critical data and maintain business continuity

Pendant type

Sidewall typeGas discharge noise of ﬁre suppression
systems may cause Hard Disc Drive failure
On September 10, 2016 in Romania, during a ﬁre drill conducted at a datacenter run by a major
European bank, the gas discharge noise emitted when the gas was released caused an unexpected failureon hard disk drives (HDDs). This made the bankʼs ATMs, online banking systems and websites go ofﬂine.
As it was a large-scale, complicated failure that persisted from 1:00PM to 11:00PM of the same day,recovery using the backup system required a lot of time.
On April 18, 2018 in Sweden, the noise produced by the errant gas discharge of an inert gas ﬁresuppression system destroyed the HDDs for around a third of the Nasdaq Nordic servers located at adata center in Vasby, a Stockholm suburb. Because of the incident, the Nasdaq Nordic markets inSweden, Finland, Denmark, Iceland, and the three Baltic states could not start trading operations at9:00AM local time until shortly after 2:00PM on the day.

Noise Reduction Nozzle■ Decreases impact on HDDs caused by the gas discharge noise■ Reduces discharge noise while maintaining the ﬁre suppression performance■ Easily replace existing nozzles

Effects caused by the gas discharge
noise of a ﬁre suppression system

Noise may affect HDDs
At a convention held by the Architectural Institute of Japanon September 11, 2010, an article entitled “Study on theeffects of sound environment to precision instruments”
was presented. According to this article, noise of 110 dBor larger may cause potential damage to HDDs.

Development of a noise
reduction nozzle

The article mentioned in the paragraph on the left
suggests that noise such as the gas discharge noise of aﬁre suppression system may have a negative impact on
HDDs. Furthermore, there are risks including business
downtime caused by the decreased speed of HDDs, aswell as loss of data.

Sound pressure level

To provide HDDs with protection
from the sound environment, Nohmi
has developed a noise reduction
nozzle that reduces gas discharge
noise using our exclusive technology.

( ) indicates the locationof measurement■Sound pressure curve during ﬁre suppression gas discharge（dB）

Airplane engine

dB120
dB

（60 m away）

130

Trumpet120（1 m away）

110

dB

Piano90（1 to 2 m away）

80

90
dB

Sidewall typeLevel of sound pressure that may affect HDDs

100（player）

100

Standard nozzle

110

OrchestradB

Pendant type

*Measured in front of the discharge point, 1 m away at a 45 angle

140

130

70

Inside a subway train

Noise reduction nozzle

0102030

40

50

6070

80

Lapse of time after discharge start（sec）

90

100

■Sound pressure level
Nitrogen ﬁre suppression system

ClassiﬁcationPendant type

Sidewall type

90 ㎥/min

90 ㎥/min

97 dB

99 dBNozzle ﬂow rate *1
Sound pressure level *2*1 The nozzle ﬂow rate indicated above is an example. Products with different ﬂow rates are also available.
*２ Results (maximum value) measured in front of the discharge point, 1 m away at a 45 angle.

■Product speciﬁcations
Nitrogen ﬁre suppression system

Classiﬁcation

Pendant type

Sidewall type

Model number

25PNQ

32PNQ

20ZMQ(U)25ZMQ(U)32ZMQ(U)40ZMQ(U)*3

Full length x full width (mm)88 90

93 11090 97

100 97118 118

139 140

1.2

2.0

1.6

1.4

2.2

3.7

Weight (kg)

*3 This product is designed to be a replacement for existing large ﬂow rate nozzles.

NOTE:
This system is intended to suppress a fire in its early stage. Please note that it may not suppress the fire if kind,
quantity and/or arrangement of combustibles in the area protected by this system is changed after installingthe system.
This system comprises cylinders filled with highly pressurized gas. Handle the cylinders with care according
to the cautions indicated on them.
The discharge of a gas extinguishing agent results in the emission of a high level of noise. This noise may
affect modern precision instruments such as hard disc drives (” HDD” ). This effect occurs when discharging
any agents described in NFPA such as inert gases, HFCs, HCFCs, FICs, FKs, and Halon.
In a communication equipment room, computer room or server room with hard disc drives installed, werecommend you to use the noise reduction nozzles described in this document, which emits a lower level
noise when discharging the gas. Please note that NOHMI does not guarantee the performance of HDD. Other
countermeasures may be effective to protect HDD, such as sound insulation and vibration isolation for HDD
housing rack (i.e. use of acoustic absorption materials and vibration-proof materials, etc.), measures toprotect HDD before discharging a gas agent (i.e. stop running HDD, evacuation of magnetic heads, etc.), or
improvement in sound-proofing of HDD itself and/or data protection (backup of data, etc.). Please note that,even if a customer replaces the existing normal discharge nozzles with the noise reduction nozzles andadopts all or part of the above countermeasures, NOHMI does not guarantee the performance of HDD.

NFPA 75 “Protection of Information Technology Equipment” states that power supply to all electronic devices
should be cut off at the same time when the gas fire suppression system starts discharging the gas agent.
The excessive pressure in a protected room caused by the discharge of the agent must be released to preventthe room from incurring damage. Therefore, a pressure relief device must be installed in the room.
Products of combustion may be released by fire. Therefore, an exhaust fan must be installed in the protectedroom and it must be activated after extinguishing the fire to remove the products of combustion.
The information contained herein does not purport to cover all the details or variations in the equipment
described, nor provide for every possible contingency that may be met in connection with its installation,operation or maintenance.
Specifications are subject to change without notice. Contact Nohmi before relying on the information.
Actual performance is based on proper application of the product by a qualified professional.
Should further information be required or should particular concerns arise that are not covered sufficiently
for the purchaser's purposes, the matter should be referred to Nohmi or your nearest distributor.
* “NN100” is the trademark registered by NOHMI BOSAI LTD.
*The original manufacturer of the NN100 system products is Koatsu Co., Ltd., an affiliate of Nohmi Bosai Ltd.
* The contents of this brochure are valid as of August 2018.

Tel: +81-3-3265-0231 Fax: +81-3-3265-5348
https://www.nohmi.co.jp/english/
Head Office: 4-7-3 Kudan-Minami, Chiyoda-ku, Tokyo 102-8277, Japan

180525Ⓓ-E-7200YO2