.BuildingSystems.ThermalZones.ISO13790.Zone5R1C.Zone .BuildingSystems.ThermalZones.ISO13790.Zone5R1C.Zone
This is a lumped-capacity simplified building model based on the 5R1C
network presented in the ISO 13790:2008 Standard. The simplified 5R1C model uses
five thermal resistances and one thermal capacity to reproduce the
transient thermal behaviour of buildings. The thermal zone is modeled with three
temperature nodes, the indoor air temperature TAir, the envelope internal
surface temperature TSur and the zone's mass temperature TMas
(the heat port is not shown in the figure), and two boundary
condition nodes, supply air temperature TSup and the external air temperature
TExt. The five resistances are related to heat transfer by ventilation HVen,
windows HWin, opaque components (split between HTra and HMas) and heat
transfer between the internal surfaces of walls and the air temperature HThe.
The thermal capacity Cm includes the thermal capacity of the entire zone. The heating and/or
cooling demand is found by calculating the heating and/or cooling power ΦHC that
needs to be supplied to, or extracted from, the internal air node to maintain a
certain set-point. Internal, Φint , and solar, Φsol, heat gains are input values,
which are split in three components.
Hven = ρa ca ∑kV̇k,
where ρa is the density of air, ca is the specific heat capacity of air and V̇k is the k-th volumetric external air flow rate. The coupling conductance Hthe is given byHthe = has Atot,
where has is the heat transfer coefficient between the air node the surface node, with a fixed value of 3.45 W/m2K, and Atot is the area of all surfaces facing the building zone. The thermal transmission coefficient of windows Hwin is calculated usingHwin = ∑kUwin,kAwin,k,
where Uwin,k is the thermal transmittance of window element k of the building envelope and Ak is the area of the window element k of the building envelope. The coupling conductance Hmas is given byHmas =hms fms Af,
where hms is the heat transfer coefficient between the mass node and the surface node, with fixed value of 9.1 W/m2K, fms is a correction factor, and Af is the floor area. The correction factor fms can be assumed as 2.5 for light and medium building constructions, and 3 for heavy constructions. The coupling conductance Htra is calculated usingHtra = 1 ⁄ (1 ⁄ Hop - 1 ⁄ Hmas),
where Hop is the thermal transmission coefficient of opaque elements. The three heat gains components are calculated usingΦair = 0.5 Φint,
Φsur = (1-fms Af ⁄ Atot -Hwin ⁄ hms Atot)(0.5 Φint+ Φsol),
Φmas = fms Af ⁄ Atot (0.5Φint + Φsol).
AWin, AWal, surTil and surAzi
must have the same dimension of nOrientations .
AWal must account only for the opaque parts of the walls (excluding windows).
The floor and roof area is entered through AFlo and ARoo
and must not be entered as part of AWal.