Heat insulation has the dimension time cubed thermodynamic temperature per mass. The SI composite unit of heat insulation is the second cubed kelvin per kilogram.

Maple knows the units of heat insulation listed in the following table.

An asterisk ( * ) indicates the default context, an at sign (@) indicates an abbreviation, and under the prefixes column, SI indicates that the unit takes all SI prefixes, IEC indicates that the unit takes IEC prefixes, and SI+ and SI- indicate that the unit takes only positive and negative SI prefixes, respectively.  Refer to a unit in the Units package by indexing the name or symbol with the context, for example, tog[standard]; or, if the context is indicated as the default, by using only the unit name or symbol, for example, tog.

The units of heat insulation are defined as follows.

A clo is defined as  degree Celsius meter squared hour per 15 degree Celsius kilocalorie.

A standard R value is defined as  square foot degree Fahrenheit hour per international table Btu.

An SI R value (RSI) is defined as  square meter kelvin per watt.

A tog is defined as  square meter kelvin per watt.