In Matlab
Background: As the name implies, indoor air pollution deals with air contamination in enclosed spaces such as homes, offices, and work areas. Suppose that you are studying the ventilation system for a truck-stop restaurant located adjacent to an eight-lane freeway. As depicted in Fig. 1, the restaurant serving area consists of one room for smokers (I know, this is not a likely scenario for Canada…), one for kids, and one elongated room. Room 1 and section 3 have sources of carbon monoxide from smokers and a faulty grill, respectively. In addition, rooms 1 and 2 gain carbon monoxide from air intakes that unfortunately are positioned alongside the freeway.
Assignment: Write steady-state mass balances for each room and solve the resulting linear algebraic equations for the concentration of carbon monoxide in each room. In addition, generate the matrix inverse and use it to analyze how the various sources affect the kids' room. For example, determine what percent of the carbon monoxide in the kids' section is due to (1) the smokers, (2) the grill, and (3) the intake vents. In addition, compute the improvement in the kids' section concentration if the carbon monoxide load is decreased by banning smoking and fixing the grill. Finally, analyze how the concentration in the kids' area would change if a screen were constructed so that the mixing between areas 2 and 4 is decreased to 6 m^3/hr.
Q = 160 m^3/hr, c = 2 mg/m^3
25 m^3/hr^2 (Kids' section)
50 = 210 m^3/hr, c = 2 mg/m^3
25 m^3/hr^1 (Smoking section)
3 (Smoker load: 1000 mg/hr)
Grill load: 2200 mg/hr
Figure 1: Overhead view of rooms in a restaurant. The one-way arrows represent volumetric airflows, whereas the two-way arrows represent diffusive mixing. The smoker and grill loads add carbon monoxide mass to the system but negligible airflow.