Type

Example

Application

Static linear equations

Transmission through component

: Power (W); L: Coefficient of static losses (W/˚C);: Difference between indoor and outdoor temperature (˚C);

: Equivalent surface (m2);: Solar energy received by a vertical wall (W/m2),: Depends by the state of variables measured at the beginning and end of the period observational (W).

: Heat transfer coefficient (W): Difference between the boundary and ambient temperature (˚C);

h: Convective heat transfer coefficient (W/m2∙˚C) and A: heat transfer area of the surface (m2).

Static nonlinear equations

Building simulation radiation

exchange (walls and ceilings)

: Emitted heat transfer rate (W);: Surface emissivity;: Stefan-Boltzmann constant () A: Radiation surface.

Dynamic linear equation

Ordinary differential equation

Heat storage

Passive/active

Energy storage

: Thermal capacity (J/˚C)

Dynamic linear equation

Partial linear

Heat conduction equation

Dynamic heat flux

: Temperature at position x and time (t) and a: Thermal conductivity (W m1∙˚C)