Many houses in the Washington area experience indoor air pollution by radon. A house of a...

Many houses in the Washington area experience indoor air pollution by radon. A house of a volume V = 300 m3 has air leaking in from the soil with a radon concentration of 5000 pCi/L and rate of 20 L/h. During the winter time, the average rate of fresh radon-free air entering the house is only 400 L/h. Radon undergoes decay following a first order reaction with a rate constant k = 0.18/day. The house can be approximated as a CSTR.  

a)      (2 %) Make a schematic drawing of the house showing air flows, concentrations, volume and rate.

b)     (2 %) What is the air flow rate leaving the house?

c)      (2 %) Write the general mass balance equation for radon in the house

d)     (5 %) Calculate the steady state radon concentration in the house

e)    (5 %) How much fresh air would have to come into the house per hour to reduce the radon concentration to the EPA guideline value of 4 pCi/L? If you did not get a result for d) you can assume that the radon concentration in the house is 50 pCi/L

f)   (2 %) How does the residence time of radon in the house compare to the half life of radon: does decay make a significant contribution to radon removal?

g)      (2 %) What else (in addition to ventilation) can be done to reduce radon levels in the house on a long term basis?

Homework Answers

Answer #1

As per the answering guidelines, I have provided the solution to the first 4 parts of the question.


Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question