SurfaceBus¶
A surface of a zone, surface side: heat exchanges, properties, weather
FastSmoothBuildings.Interfaces.SurfaceBus, connector (source)
Purpose
A surface of a zone, surface side (propsBus_a of the walls and windows of
Envelope): the heat exchanges with the room, the properties
the zone needs to share them, and the weather.
| Variable | Unit | Set by | Meaning |
|---|---|---|---|
con.T | K | zone | Air temperature of the zone |
con.Q_flow | W | surface | Convective heat flow rate (flow variable) |
rad.T | K | surface | Temperature of the room face of the surface |
rad.Q_flow | W | zone | Long-wave and solar heat flow rate (flow variable) |
A | m2 | surface | Area seen from the room |
epsLw | 1 | surface | Long-wave emissivity of the room side |
absSol | 1 | surface | Diffuse solar absorptance of the room side |
tauSol | 1 | surface | Solar transmittance back to the outside (windows) |
isFloor | 1 | surface | 1 for a floor, 0 otherwise |
QTraDir, QTraDif | W | surface | Direct and diffuse solar radiation transmitted into the room (windows) |
hConInt, hConExt | W/(m2K) | zone | Fixed interior and exterior convection coefficients, 0 for the natural convection and wind-dependent laws |
wea | zone | Weather, forwarded by the zone |
The heat flow rates are positive into the component that holds the port, so the convective and radiant heat
gained by the surface is con.Q_flow + rad.Q_flow on the surface side, the opposite on the
zone side. The zone shares the long-wave exchange through a radiant star with the weights
epsLw*A, the transmitted diffuse radiation in proportion to absSol*A (with
tauSol*A lost back to the outside), and the transmitted direct radiation on the floors first.
Use
Connect it to one element of the
ZoneSurfaceBus array
propsBus of a zone, which has the same variables with the opposite causality.
Revisions¶
- October 2026: moved from trano's
FastModel.Interfaces.