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At 03:07 PM 2024-01-15, David Eddleman via Outages-discussion wrote:<br>
<blockquote type=cite class=cite cite="">"Reuse the ducting"
doesn't work well. The cold air has to be blown to specific rows for the
datacenter to work. Remember hot row, cold row. Racks of servers make
great windbreaks since they're giant blocks, blocking any blowing air, so
the cold air has to come in via the cold row ducting to be effective.
Simply opening the doors and bringing fans in only slightly reduces the
ambient temperatures, but it doesn't get cold air where it needs to go,
as heat simply flows in the direction of least resistance to fill a void.
Plus depending upon the failure within the chiller system the whole
system may shut down to prevent the system from eating itself during a
malfunction. Even though the heat exchanger isn't working, the blower
motors may have a physical disconnect in the event of said event.
Residential HVAC systems have safeties that can disconnect the whole
system in the event condensation drains are clogged, for
example.<br><br>
Datacenters in Greenland have other problems as well, despite being in an
arctic environment for many parts of the year. Snow is actually a
fantastic insulator, so you still need HVAC even when the environment is
seriously cold outside. You need a way to pump cold air in and hot air
out.<br><br>
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When we build a facility, the design we use has a mixing chamber where
the cold air supply from the internal air handler returns can be combined
with filtered outside air. We use actuators to control the dampers,
and a variable speed fan wall with one way louvers to draw the air in. We
also use humidity sensors to make sure we're not introducing too much
humidity or drying the air out too much. In the facilities where we
did install humidifiers, we never have ended up needing them (must be due
to our climate). We have pressure relief vents with weighted
louvers to exhaust any excess air that we draw in when in free cooling
mode. It seems to work well, and we track all the state info on our
BMS to make sure nothing gets out of whack. The whole setup saves
us a bunch on electricity, as we almost never use mechanical cooling in
the winter months.<br><br>
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<font face="arial">-- <br><br>
Clayton Zekelman<br>
Managed Network Systems Inc. (MNSi)<br>
3363 Tecumseh Rd. E<br>
Windsor, Ontario<br>
N8W 1H4<br><br>
tel. 519-985-8410<br>
fax.
519-985-8409<x-tab> </x-tab>
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