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7X24 MAGAZINE FALL 2014
When this occurs, more air is forced through the IT
equipment than required by the equipment. ASHRAE
explicitly recommends against this condition of over-
pressurized cold aisles. The open-sealing architecture
of Modular Containment solves this problem by
containing cold air to the level needed while allowing
any excess volume to escape when required.
The Rack Top Baffles and Bi-Directional Doors install
quickly and easily without the use of tools. Moving or
reconfiguring these components is simple and does
not require special skills. The rack top vertical panels
work well in a traditional raised floor computer room,
but can also provide similar benefits in a slab floor
environment with dedicated cold aisle supply ducts.
In a flooded supply/flooded return environment,
caution should be used when installing Modular
Containment, or for that matter, any type of barrier to
airflow in the computer room. Disruption of airflows in
this scenario could cause inadvertent rack inlet air
temperature increases.
Modular Containment CFD
Analysis
Computational Fluid Dynamic (CFD) analysis has
shown that Modular Containment can achieve many
of the core benefits of traditional containment, such as
reduced inlet temperatures, energy savings, and
increased rack densities, but without the costs or
inconveniences that accompany the current
containment options. The major benefit of Modular
Containment is its ability to attain a similar level of
efficacy with a simple and cost-effective design.
The CFD model shows significant recirculation of
exhaust air over the tops of the racks. The color red
indicates temperatures exceed ASHRAE TC9.9
recommended temperature of 80.6 Deg F.
With Modular Containment, the rack inlet
temperatures become very consistent top to bottom
and are all below the ASHRAE TC9.9 recommended
temperature of 80.6 Deg F. The maximum reduction
in rack inlet temperatures was 10.3 Deg F and the
average reduction in rack inlet temperatures was 3.7
Deg F. It is important to note the racks now have
uniform inlet temperatures. This enables further
optimization of cooling tile airflows and cooling unit
operational set point temperatures.
The CFD model shows significant recirculation from
back to front on the end aisle racks. Hot exhaust air
from the rear of the racks is wrapping around and
being pulled into the equipment inlet on the front of
the rack. The color red indicates temperatures exceed
ASHRAE TC9.9 recommended temperature of 80.6
Deg F.
With the installation of the Bi-Directional Doors, the air
recirculation around the ends of the aisles is stopped.
All IT equipment inlet temperatures now meet the
ASHRAE TC9.9 recommended temperature of 80.6
Deg F. For the aisle end cabinets the maximum
reduction in rack inlet temperatures was 10.2 Deg F
and the average reduction in rack inlet temperatures
was 6.2 Deg F. As before, the uniformity of the rack
inlet temperatures enables further optimization of
cooling tile airflows and cooling unit operational set
point temperatures.
Fig. 2 – Front View of Racks
Fig. 3 – Front View of Racks
Fig. 4 – No Aisle Containment (end view)
Fig. 5 – With Modular Containment (end view)
