Heat: Dell Server Thermal Load (BTU/hour)

It’s a shame that Dell doesn’t list the thermal loads of their products in the datasheets at the online store. It’s a shame that it took several Google searches to get close to a link with the info, then mine the Google cache of a Dell support forum and find/follow a chain of links before I could get that detail.

As it turns out, there’s some Dell and the Environment page where they list all their products and their environmental properties/certifications/regulatory compliance. When you do find it, you’ll discover that a Dell PowerEdge 2650 is listed with a minimum heat dissipation of 878 BTU/hour, but no maximum. The datasheet for the similar Dell PowerEdge 1850 server claims 854.69 to 1,387.73 BTU/hour.

It would of course, be better if Dell offered a link like how hot does my server get? or something else like that. Let’s hope Google indexes this.

15 thoughts on “Heat: Dell Server Thermal Load (BTU/hour)

  1. I’ve been researching the load for my servers in our new machine room at the CU Stadium. I use the Dell Rack Advisor to calculate heat and power in BTU and Amps. I like it because it tells you how you should be loading your rack bottom to top and gives you power and heat information down to things like the fan kit. It will also tell you how many power strips you need and part numbers for everything. Unfortunately the Dell Rack Advisor 5.0 does not include current servers like the 1850, 2850 etc. For now I’m guessing on the few 2850s we have and comparing them to a 2650. Maybe we could figure out a ratio to use vs Dells operating at a DOS prompt temperature using the values from the rack advisor. Use google to look up rack advisor 5.0.

  2. Dell’s new version – Dell Product Configuration Calculator – has information about all of the newer servers, as well as new peripheral items and storage equipment. This configurator returns more detailed information than the rack advisor does, however some of the older models such as the PE1550, etc., are not available. Your best bet is to use both if you have various machines in your environment. Go to Dell.com and look up Product Calculator.

  3. Is there any formula to calculate heat dissipation of a server? what is the basic inputs required to calculate BTU of a server. I need to design the AC requirement for my data center and hence this is most important. Note i have server of various model ranging from 4 years old to recent one.

  4. I’ve been told that MAX Watts being used multiplied by 3.413 provides BTU/hr.
    Not all machines use the entire Wattage available in their Power Supply, but it doesn’t hurt to over estimate cooling requirements.
    Then divide the BTU totals for room by 12000, to get Cooling Tonnage.

    [tags]Thermal Load, BTU/hour[/tags]

  5. I dug up this information on the PowerEdge 1750

    PowerEdge 1750:
    Power supply:
    Wattage: 320 W (AC)
    Voltage:100–240 VAC, 50/60 Hz, 3.9–2.0 A
    Heat dissipation: 1026 BTU/hr maximum per power supply <—- notice the “per” power supply
    Maximum inrush current
    Under typical line conditions and over the entire system ambient operating range, the inrush current may reach 25 A per power supply for 10 ms or less.
    System battery:3.0-V lithium ion coin cell

    and then similarly for the Power Edge 1850, because I needed to compute heat dissipation for my company’s datacenter.

    Power Edge 1850:
    AC power supply (per power supply)
    Wattage 550 W
    Voltage 84 -264 VAC, autoranging, 47-63 Hz, 7.6 A
    Heat dissipation 2130 BTU/hr (theoretical maximum)

    If you would notice, the PE1850 theoretical maximum is over 2000 BTUs because these blades have two redundant power supplies. Whether they are both in use or not at the same time is the question I am unsure of, so I just gave the datacenter 2100 max BTUs as the heat dissipation. I really wish Dell would be more clear about this kind of stuff.

  6. Hay guys i am just curious in order to minimize heat, would it be better to load server racks from top bottom or bottom up? does this make much of a difference if i have 5x 2RU serverrs in a large 45 RU rack?

    Thank you

  7. I took the post from Gavin and did the following calculation:

    Total Power: 374 Watts
    Total Thermal: 1277 BTU/hr.

    Since there is 3413 BTU/hr in 1kW, we have:

    .374 kW * 3413 (BTU/hr.)/1kW = 1276.462 BTU/hr.

    Which is almost exactly what the specs say for total thermal dissipation.

    Meaning, 99% of the total power consumed is dissipated as heat. This is in line with what you read about servers being only 1% efficient.

    Therefore, you can take the total power your servers use, in watts, and just divide by 3517.2 to get total tons refrigeration needed. 1 ton of refrigeration is equivalent to 3517.2 watts.

    I _think_ I got this down right. Someone correct me if I’m wrong.

  8. The tonnes you discuss Garry are Sensible Tonnes. Heat load is divided into Sensible and Latent.


    Your AC might have a sensible heat ratio of say 0.73 to 0.95. Let’s say your AC unit has a 0.85 sensible heat ratio.

    You need 1 ton of sensible heat cooling, therefore you need a unit sized at 1 / 0.85 = 1.18 Cooling Tons Nominal. This becomes crucial when you have say 50 tons of load in a computer room.

  9. hi;
    I have the specification of the server but i dont know how to calculate the heat dissipation of it

    • Hi,
      I am looking for an AVERAGE heat dissipation for some equipment that a

      client is putting into their server room. I am trying to size an air
      conditioner that will cool this room to an acceptable temperature. I
      could size it for the max heat dissipation but the client is under the

      impression that the AC will be oversized quite a bit. If you could
      give me average heat dissipation for the following equipment, I would
      appreciate it. They are providing


      1. Dell 42U Racks with Fan qty 3

      2. Communication Rack with Fan qty 1

      3. Dell Power Edge 2950 Servers (2U each) qty12

      4. Dell Power Edge 1950 Servers(1U each) qty3

      5. Dell Power Edge 850 Server (1U) qty1

      6. 5KVA APC UPS qty1

      7.KB + LCD monitor qty1+1

      8.EMC CX3-10c SAN qty1

      9. EMC Enclosure with 15 FCC HDDS qty3

      10. EMC 1U UPS (KVA?) qty1

      11. Dell Power Vault TL4000 Autoloader Tape Library qty1

      12. 3KVA APC UPS qty1

      13. 1KB + LCD monitor qty1+1

      14. Dell Blade 1855 chassis (with 6 Blade Servers) qty1

      15. Dell Power Edge 4400 Server (5U each) qty1

      16. Dell Power Edge 2600 Server (4U each) qty1

      17. Dell Power Edge 2800 Servers (2U each) qty 2

      18. Nokia IP 390 units qty2

      19.Cisco Catalyst 4507R-E qty1

      20. Cisco Catalyst 3560 qty2

      21. Cisco Catalyst 3750 qty2

      22. Cisco PIX 505 qty1

      23. Cisco 1850 routers qty2

      24. 3KVA APC UPS qty1

      25. Power Ware 20KVA UPS in the qty1

      Also…from your experience, what kind of overall percentage do you
      find in heat dissipation vs. power input for similar equipment?

      Thanks & Regards

      Joseph Valooran
      Hasibat Information technologies Co.K.S.C
      P.O.Box:No.27728 Safat
      Tel: +965 2224 0600 Ext1056
      Mob: +965 6665 8813
      Email: joseph@hasibat.com

  10. If you need a quick estimate of the heat load of server equipment just use to the max input power. Servers are basically resistance heaters and turn much of the electrical input into heat. Take the max power input and convert it all into heat. This is the maximum heat that the server could ever put out, need conservation of energy here. For better more accurate estimates it is always better to try and find the manufacturer data, sometimes a phone call is best to track that information down.

  11. Typically, server rooms are ALL sensible heat. There is no source for latent heat, so a sensible heat ratio of .95 or even 1.0 would work fine unless you have infiltration or people or humidification in the space. You may want to introduce humidification if your relative humidity drops below 35% because low humidity contributes to static potential.

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