Data centers are an increasingly critical part of our economy and everyday lives. Yet, they’re packed with electronic equipment that generates a great deal of heat, which is difficult for traditional HVAC systems to handle.

In response to this, significant advances in cooling technology and building design have been developed to help data centers maintain optimal equipment temperatures and keep their servers running. However, these innovations may make it harder for traditional passive smoke detection systems to sense fire.

Detecting fires early or, ideally, before they happen, is always critical, but this is especially important for data centers. In fact, the most common cause of fires in data centers is the building system itself, such as power distribution equipment, according to the FCC. And fires and fire alarm malfunctions actually account for more than 42% of the total cause of downtime at data centers due to non-IT causes.

Data center disruption has the potential to result in costly, crippling interruptions that go far beyond the data center itself, impacting business customers, their customers, and so forth. That’s why it is so important to develop new approaches to smoke detection. We must catch fires as early as possible, so they can be treated as maintenance issues instead of firefighting exercises.

New Systems, New Challenges

There are two significant trends in data centers that challenge traditional fire detection systems.

First, data centers dissipate heat created by faster and more powerful electronic devices through HVAC systems. This increases airflow by rapidly moving air through the facility, exhausting the hot air, and bringing in cool air from outside when conditions permit.

The second trend is increased colocation, in which data centers host multiple companies that outsource data processing and storage needs in the same space. For example, while an entire floor might be dedicated to one company’s data, another company may require just a single server, rack, or suite of server space and take up a small section of a floor. These are typically secure areas, making access for routine test, inspection, and maintenance exercises more challenging.

Why do increased airflow and new designs make fire detection more difficult?

For smoke detection systems to work properly, the smoke must travel from the source to a sensor in sufficient, detectable density. The traditional approach to smoke detection is to place sensors near or at the ceiling of floors because smoke rises. However, heavy cooling efforts and design changes in data centers create airflows and smoke barriers that dilute and exhaust smoke, meaning that only small concentrations may reach the ceiling in the early stages of a fire.

It also takes smoke significantly longer to reach sensors at the tops of high ceilings, where they are typically placed in data centers. Installing sensors closer to equipment can be hindered by the fragmented nature of colocation barriers, such as ductwork, cable trays, and so on. As a result, traditional fire detection systems may not sound until the fire is potentially catastrophic in size.

Finally, fire codes often lag behind advancements, resulting in confusion around compliance measures as they relate to actual safety. Many data center operators do not realize that compliance with fire codes will likely not protect their digital assets.

A Different Approach

These challenges require a different approach to smoke detection and alert systems at data centers — one that works with the specific environmental and operational conditions. Air sampling technology, which can pinpoint fires at their earliest stages, is one way to overcome the obstacles caused by data center cooling technology and building design.

Air sampling, or aspirating, smoke detectors continuously sample air to provide very early warning of impending fire hazards and detect threats before they escalate. Some devices even provide multilevel warnings and are equipped with wide-range sensitivity to identify even the smallest amount of smoke in the air, preventing even a small fire from causing irreparable damage.

Unlike traditional detection technology — which is largely passive, waiting for smoke to reach sensors — aspirating devices actively seek out and test air near the most likely sources of electrical fires around buildings. For instance, the momentary presence of smoke in more ventilated areas like air ducts makes it harder to quickly and accurately detect smoke. Early detection technologies can be placed in narrow spaces to detect smoke, drawing air from targeted locations throughout data centers back to a central system that continuously monitors for trace amounts of smoke. In this way, potential fires are intercepted at the source.

There are other advantages to these systems as well. Devices can be positioned in hard-to-monitor places, like ceilings, return air grilles and openings, raised floor and ceiling voids, and inside cabinets, to alert users to overheating. In addition, sampling across outside air intakes helps omit external pollutants from outside of the buildings, which can damage equipment or trigger false alarms.

When business continuity is imperative, and building needs and resulting environments complicate the detection process, early fire alert technology like aspirating smoke detectors can help to identify and address problems before they become catastrophes.