Convergence for thermal mass

Hello this code is to find the temperature at every point in walls, roof, floor assemblies. The code is run for 5 days for every hour of the day. The temperature obtained should never be below -5 degrees Celsius. A random initial temperature is given and it is expected to see the temperature converge quickly over the period of 5 days. However in my code, the temperature does not seem to converge and temperature values of below -5 degrees celcius is obtained. I would also like for the temperature over the 5 days for the 24 hours to be saved into an Excel file for easy access. Can anyone help please? This is a transient state thermal analysis. %BLDG 476 Project 1: Thermal analysis of existing building in Algeria clc clear;

%assumptions %air is thermallywell mixed %all surfaces have uniform temperatures %one dimensional heat conduction within materials

%Room dimensions in meters (m) R_w=12; R_l=7; R_h=3; %Room Volume units in cubic meters (m^3) R_vol=R_w*R_l*R_h;

%% %Information for windows %Area in meter square (m^2) A_win=2*1.2; %thickness of window in meters (m) x_win=0.003; K_win=7.42; %thermal resistance of window of wood frame material in W/(m^2*K) %Table 4 Chap15 ASHRAE Trans=0.83; Absorb=0.6;

%% %Information for walls %Area in meter square (m^2) A_nw=R_w*R_h; A_ew=(R_l*R_h)-A_win; A_sw=(R_w*R_h)-A_win; A_ww=R_l*R_h; %absorbivity of window according to table

Answer 1

[Image Analyst]

Use writetable() to write your table to Excel.

Use max() to clip your values to -5 or above

data = max(data, -5);