1. Lecture Objectives:
Energy balance and modeling
HW1b

2. Homework assignment 1b Top view T_east_o Teast_i Tinter_surf Tair_in
conduction
Tair_in
IDIR
Idif
Glass
Tinter_surf
Tsouth_i
Tsouth_o
Teast_i
T_east_o
Tair_out
Styrofoam
Surface radiation
Surface
radiation
2.5 m
10 m
10 m
South
East

3. Homework assignment 1 Room energy balance
1) External wall (south) node
Qsolar_ext_south+C1·A(Tsky4 - Tsouth_o4)+ C2·A(Tground4 - Tsouth_o4)+hextA(Tair_out-Tsouth_o)+Ak/(Tsouth_in-Tsouth_o)=0
Qsolar_ext_south=asolar·(Idif+IDIR) A
c1=esky·esurface_long_wave·s·Fsurf_sky
2) Internal wall (south) node
C3A(Tinternal_surf4-Tsouth_in4)+C4A( Test_in4-Tsouth_in4)+ hintA(Tair_in-Tsouth_in)+kA /(Tsouth_out--Tsouth_in)+Qsolar_to int _south_surf =0
C3=esouth_in·einternal_surfs· Fsouth_in_to_ internal surface
Qsolar_to int _south_surf = portion of transmitted solar radiation that is absorbed by internal south surface

4. MatLab Example
Example code is posted on the class website MatLab at: