Ask Question
3 July, 08:22

You get invited to a party at a 1,200 sf apartment, where there are a total of 23 people. The apartment has ceilings that are 8 ft above the floor. Three people begin smoking 2 cigarettes per hour each. The air handler system has a make-up air ventilation rate of 600 cfm. Assume an overhead fan ensures the air is well-mixed. Eye irritation from formaldehyde can start at concentrations of 0.01 ppm, with irritation of the lungs at 5 ppm. Will the concentrations become high enough to cause eye irritation

+1
Answers (1)
  1. 3 July, 12:19
    0
    concentration of air = 0.0000366 ppm is not sufficient to cause any eye irritation

    Explanation:

    Average amount of aldehyde generated by a cigarette = 1 mg = 10⁻⁶g

    Room volume = Height * Base area

    Room volume = 8ft * 1200 sq. ft = 9600 cubic feet

    number of people in the room = 23

    If 1 person smokes 2 cigarette in 1 hour,

    23 people will smoke 23*2 cigarettes = 46 cigarettes in 1 hr

    Mass of aldehyde generated by 1 cigarette = 10⁻⁶g

    Mass of aldehyde generated by 46 cigarettes = 46 * 10⁻⁶g

    Based on the law of mass conservation,

    Mass of aldehyde coming in = mass of aldehyde going out = Rate of accumulation of aldehyde

    Rate of accumulation of aldehyde in the steady state = 0

    m*C*V = 0

    m = 46 * 10⁻⁶g

    C = concentration in the steady state

    V = Volumetic flow of the fresh air

    V = 600 ft³/min = 600 * 60

    V = 36000 ft³/hr

    Density = Mass/volume

    Density = 46 * 10⁻⁶g / 36*10³

    Density = 1.28 * 10⁻⁹ g/ft³

    If the density of air is taken as 36 g/ft³

    concentration = (1.28 * 10⁻⁹ g/ft³) / 36 g/ft³

    concentration = 3.66 * 10⁻¹¹g/g

    1*10⁻⁶g/g of air = 1ppm (part per million)

    concentration of air = (3.66 * 10⁻¹¹) (/1*10⁻⁶)

    concentration of air = 3.66 * 10⁻⁵ppm = 0.0000366 ppm

    concentration of air = 0.0000366 ppm is not sufficient to cause any eye irritation
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “You get invited to a party at a 1,200 sf apartment, where there are a total of 23 people. The apartment has ceilings that are 8 ft above ...” in 📘 Engineering if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers