Question

What is the air change rate (ACH) for a 100 ft^2 (9.3 m^2) space with a 10 ft (3.0 m) ceiling and an airflow rate of 200 cfm (95 L/s)? A. B. C. 2 6 12

Answer 1

The ACH is 12/h

Solution:

As per the question:

Area of the space,
`A_(s) = 100 ft^(2)`

Height of the given space, h = 10 ft

Air flow rate,
`Q_(a) = 200 cfm`

Now, to find the Air Change Rate (ACH):

We calculate the Volume of the given space:

`V_(s) = A_(s)* h = 100* 10 = 1000 ft^(3)`

Now, the ACH per min:

=
`(V_(s))/(Q_(a)) = (1000)/(200) = 5/min`

Now, ACH per hour:

=
`(60)/(5) = 12/h`