×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Server Racks

Server Racks

Server Racks

(OP)
i found myself calculating for the heat dissipation of server racks. they have 12 server rack with 3000w per racks, that's 36kW total load of racks. how can i size up the air conditioning system of the server room. (the server room has only 12racks the UPS is separated to the adjacent EE room. thanks

RE: Server Racks

the short answer is (12) x 3000W = 36,000 W = 36kW ~= 10 tons for the IT load.
You should still account for other loads some of which will be dependent on your cooling system topology. lighting, PDU transformers, fan gain etc.
Based on your question I assume this is slightly outside your normal wheelhouse. You should be careful about clarifying and documenting the stated IT load. is this a design load given by the client? is it the UPS capacity supplied to the room? is this the nameplate of the servers going into the racks? typically servers will not operate anywhere near nameplate so bear this in mind.
You should also talk to your client about levels of redundancy, do they want one cooling unit sized for the capacity? do they want a back-up? do they run them both or operate lead/lag.

RE: Server Racks

Every watt of power used by a server is dissipated into the air as heat.

RE: Server Racks

Conservation of energy - where else will it go?
sure some will go into changing state of some electrons on the circuit boards and some will be turned into kinetic energy by the server fans, but in a steady state ultimately both of these and every other type of energy consumption in this space will become heat at the same rate that electrical energy is provided

RE: Server Racks

Just like you would any other electronic device in the space, only on steroids; it is 10 tons of sensible load.

Most server rooms I've seen and designed will have their own air conditioning units which are frequently located in the server rooms themselves. Commonly called CRAC (Computer Room Air conditioning) units, they are not designed for lots of ventilation air. Having a dedicated AC for server rooms allows them to be run 24/7 while HVAC for the rest of the building goes between occupied and unoccupied modes constantly resetting temperature set points.

When you do your air distribution layout, put diffusers around the perimeter of the racks or above aisles; locate return air grilles above the racks. This will help to keep the environment in the room more comfortable for the technicians.

Redundancy is highly recommended, how much is a conversation to be had with the client. Typically I've seen 2 units at 2/3 total capacity for the space. More units means smaller units. There is no code or guide that I'm aware of dictating how much AC redundancy to install, it will depend on available space and how valuable the servers are to the client.

RE: Server Racks

Second or Third what everyone has already commented...
Your server load is all sensible gains. Obtaining accurate information about these servers is critical. Be aware that servers can have redundant power supply units, i.e. two 500 watt power supplies. When obtaining information from the client, I've had instances where they provided the sum of the power supplies (1000 W) as opposed to what is really being utilized (500 W ~ 250W actual). The diversity factor should be adjusted to the server room application.

RE: Server Racks

The trend with servers is always towards server energy density increasing (per "blade"), I would establish with the client what scalability they want for your system. They aren't going to want to shut down while new ductwork is installed. That's why modular CRAC units are popular.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources