Arc companion

What It Draws

Turns a facility's stated capacity into what it will actually draw from the municipal systems, and into the ordinary comparisons a person can use in a room. Every coefficient is visible and editable, and it tells you when the water argument is not available to you.

Sociable Systems · Calculator

What It Draws

A facility is proposed on a serviced lot near you. This turns its stated capacity into what it will actually draw from the municipal systems, and into the ordinary comparisons a person can use in a room.

Every coefficient below is visible and editable, with its basis stated. Change any of them and the arithmetic changes in front of you, which is the point: a number you cannot interrogate is not evidence. Nothing is sent anywhere. This models a facility class and describes no particular application.

The facility

IT load (MW, the computing capacity, not the connection size)

If only a connection or contracted figure is published, use it and note the basis in your write-up.

Utilisation (%)

PUE (facility power ÷ IT power)

PUE 1.2 to 1.4 covers most modern builds. Utilisation below 100% because racks are rarely full from day one.

Cooling design (the variable that decides the water answer)

Site area (hectares)

Permanent jobs claimed

Local context, and the coefficients

Municipal electricity supply (MW, leave 0 to skip the share calculation) Municipal water supply (megalitres a day, leave 0 to skip) Water source (changes the argument, not the volume) Restriction scenario (what households are held to when the system is constrained)

Cape Town held households to 50 litres a person a day in 2018. The scenario matters because a facility's draw is contractual and a household's allocation is not.

Household electricity (kWh a year)

Household water (kilolitres a year)

Defaults are ordinary urban household figures and vary widely by city and by tariff block. Replace them with your municipality's own and the comparisons become locally defensible.

Housing density for the land comparison (dwellings per hectare)

40 is medium-density walk-up. Use 15 for freestanding, 100+ for high density.

Water intensity if evaporative (litres per kWh, low and high)

Published industry ranges put full evaporative at roughly 1.8 to 4.0 litres per kWh, adiabatic at 0.2 to 0.8, best-in-class hybrid operators near 0.26 to 0.30, and direct liquid cooling with dry coolers at zero.

Electricity, and this is the argument that survives

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Water, by cooling design

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Compare every cooling design

Design	L/kWh	Ml a year	Households

When the system is constrained, who yields

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The land, and what else it could carry

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Benefit intensity, the ratio a reviewer will compute anyway

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How to use this without embarrassing yourself

Lead on electricity, not water. Electricity is the argument that survives contact with an engineer. Where a facility is closed-loop, the water case is weak and reaching for it signals that the speaker has not checked. This calculator will tell you when that is your situation.
The cooling choice moves the water answer by three orders of magnitude, and it is frequently not stated in an application. If it is not stated, that is the finding: ask which design, and which instrument holds it. A cooling choice on a marketing page has the binding force of a marketing page.
Household equivalents are a translation, not a claim about substitution. The facility does not take those homes' water. It draws on the same system, and the comparison exists to make a number legible, not to allege theft.
Use your own municipality's figures. The defaults are ordinary urban values. Replace them and the output becomes locally defensible rather than indicative.
State the basis of the load figure. A contracted connection size, an application figure and a press announcement are different numbers, and they must never be summed together.