Webel: Mathematica: TIP: Maintain a Package library of Quantity variables for frequently used units using a naming convention unit$[unitSymbol] and unit[DescriptiveName] or unit[Acronym]

Even with the Wolfram Alpha lookup using [CTRL]= entering the unit of a Quantity can be tedious, especially for complex units, such as this for a heat transfer coefficient:

Quantity[1,(("Watts")/("Kelvins" ("Meters")^2))]

The following unit-alias naming convention works well:

For a unit that has a clear unit symbol use the name unit$[unitSymbol], where [unitSymbol] is usually the official SI (ISQ) symbol. You can then type 'unit$' and prompt on it to choose the desired unit. For example:

unit$W = Quantity[1, "Watts"];

unit$kW = Quantity[1, "Kilowatts"];

unit$m = Quantity[1,"Meters"];

unit$mm = Quantity[1,"Millimeters"];

You can also use just the prefix 'unit' together with a descriptive name to enforce uniformity across a project:

unitHeatLoad = Quantity[1, "Kilowatts"]; (* Industry-typical non-SI choice *)

unitHeatTransferCoefficient = Quantity[1,(("Watts")/("Kelvins" ("Meters")^2))];

Frequently used ones can be further aliased thus:

unitHTC = unitHeatTransferCoefficient; (* Short-cut alias *)

This makes for far more readable code, and your typing hands will be happier. You can also search easily for unit usages. And you can change unit conventions across a project more easily.

However, be aware that multiplication, addition, and division of Mathematica Quantities involving units for temperature have special treatment!