Server Room Cooling Costs

In 2009 when Boho One first opened I never found any good information on the cost of cooling online, 5 years later I now have a good idea.

In its simplest form Boho One’s Server Room consists of 17 cabinets and four Air conditioning units. Each Cabinet is sub metered and the Air condition has meter on in the main electrical distribution room. Equipment is on and cooled 247.

Meter readings as of the 26th of August 2014 are;

• Server room Total : 367946 KWH 
• Air conditioning Total : 653266 KWH 

By dividing these two values we calculate the Aircon factor as 1.78

Which means for 1 Kilo Watt Hour of computing it take our building 1.78 Kilo Watt Hours to cool it. Therefore in this simple example for every 1 KWH on someones meter they are actually charged for 2.78 KWH.

Lets add complexity

We take monthly meter readings for charging our customers and therefore have a bit of data to work with. Now to make the information a bit more interesting I'll add in the mean temperature of Middlesbrough for the period.

Meter period	Average Temp	Aircon Factor
September	14º	1.63
October	11º	1.73
November	8º	1.07
December	6º	0.93
January	4º	0.91
February	4º	1.10
March	6º	1.07
April	8º	1.32
May	11º	1.65
June	14º	2.36
July	16º	2.14
August	16º	2.35

As you can see come the hot months it is extremely expensive and this last year actually averages out to be 1.5 which is quite a nice figure to tell people.

We have to charge on a month by month basis as we cycle through tenant in a similar month to month cycle. Unfortunately this is not convenient for tenants who use a similar amount of electricity each month, they have their electric charge more then double in summer .

Just looking at the graph you can see that outside temperature is not the only factors

Other factors

• During average loads two of the four air conditioning units can manage the temperature. We have no way of tracking  he number of units are active in a period or those in fault.
• The server room windows face east and can catch the morning sun. Although sunlight is rare in the North of England it could randomly add a degree or two to the server room mean temperature.

Raw data spreadsheet Numbers Format or Excel Format

Weather data from Accu Weather http://www.accuweather.com