Question

1. A girl purchased a mobile home last year. She has been suffering from severe

allergic symptoms and has detected a strong odor of formaldehyde. An analysis of
the mobile home air has revealed that the formaldehyde concentration is 0.28 ppm,
the ventilation number is 0.56 air changes per hour. She is recommended to
increase the ventilation rate to reduce the formaldehyde concentration below the
threshold odor level of 0.05 ppm. Assuming the mobile home volume is 148 m²³ and
that the outdoor air concentration is 0. Estimate the ventilation number required to
achieve the threshold odor level. (Assume no decay of formaldehyde)

If Q is 80.08 what is a ventilation number? How do I find the correct answer?

Answer 1

To find the required ventilation number to reduce formaldehyde concentration in a mobile home, you divide the given ventilation rate (Q) by the volume of the home. With a Q of 80.08 and volume of 148 m³, the ventilation number is calculated to be 0.54 air changes per hour.

The question asks how to calculate the ventilation number required to reduce formaldehyde concentration in a mobile home's air to a safe level. Given the formula for the ventilation rate (Q), which is the product of the ventilation number and the volume of the space (Q = ventilation number x volume), we can rearrange the formula to solve for the ventilation number: ventilation number = Q / volume.

With Q given as 80.08 and the volume of the mobile home as 148 m³, the calculation is as follows:

Ventilation number = Q / Volume
Ventilation number = 80.08 / 148 m³
Ventilation number = 0.54 air changes per hour.

To achieve the desired formaldehyde concentration of less than 0.05 ppm, you would adjust the ventilation number accordingly while considering the initial concentration and the recommended increased rate of air changes.