ASHRAE Journal Supplement - AMCA InMotion - November 2024 - 13

smoke-control and evacuation strategies. As such, they
are tied to a fi re panel and can be controlled by the fi re
marshal during a life-safety event. Life-safety dampers
can be used to control airfl ow if a modulating actuator
is utilized. Use of modulating actuators on life-safety
dampers can reduce pressure drop by eliminating a
control damper.
Thermally insulated. Some dampers are thermally
insulated to prevent condensation from forming on
their blades. Condensation can become airborne and pose
a danger to I.T. equipment, leading to costly downtime
and even failure. Additionally, it is a source of mold and
bacteria growth that can lead to sick building syndrome.
Thermal-dispersion airfl ow measurement.
Credit: IR_Stone/iStockphoto
damper applications are referred to as backdraft, barometric
relief, combination fire and smoke, thermally
insulated, and thermal-dispersion airfl ow measurement.
Backdraft. Backdraft dampers mostly are used in
conjunction with fan banks. The principal purpose is to
prevent short-circuiting of airfl ow. Short-circuiting limits
the ability to properly control air and reduces overall
system effi ciency. Of course, any fan-inlet airfl ow obstruction
impacts performance, so it is necessary to consider
a data center's effi ciency holistically. It is possible that
reduced fan performance can be offset by other design
benefi ts and effi ciency gains. Recently introduced backdraft-damper
designs are claimed to have no fan-performance
penalty, so this may be a moot point.
Barometric relief. Barometric relief dampers
typically are used in exhaust-air applications. Some
designers replace backdraft dampers with actuated control
dampers. For sophisticated data-center designs, this is
desired because it offers optimum control.
Combination fi re and smoke. Combination
fi re and smoke dampers restrict the transfer of fi re and
smoke to prevent loss of life and mitigate damage to buildings.
UL-rated life-safety dampers are a component of
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Dampers equipped with thermal-dispersion airflowmeasurement
instrumentation facilitate tighter control
of environments. These products work in concert with
building-automation controls to ensure optimum performance
and effi ciencies. Directing conditioned air to exact
locations is essential, especially in high-density data
centers where servers are stacked to maximize profi t and
facility footprint. These dampers can be used to measure
any airfl ow within a complex data-center design. Some
data centers are exploring the use of AI for more exacting
control of conditioned air.
Data-Center Louver Applications
Though sometimes considered a commodity and given
short shrift in facility design, louvers can play a critical
role in overall system effi ciency and security. A savvy
designer considers free area, water penetration, and pressure
drop. Though that may appear easy, manufacturer
literature can be easily misunderstood. When comparing
products, ensure all data are backed by a third-party test
agency and that identically sized units were tested. Maximizing
free area while eliminating water-penetration risk
and improving effi ciency should be the goal.
Acoustic louvers are used to mitigate objectionable noise,
a concern particularly with edge-computing facilities located
near or within high-population centers. Here, a designer
may consider outside-air louvers with acoustic properties
to reduce or eliminate noise in certain sound bands.
For a data center located in an area prone to severe
weather, such as tornadoes or hurricanes, designers
2024 AMCA inmot ion
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ASHRAE Journal Supplement - AMCA InMotion - November 2024

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