Question

The minimum fresh air requirement of a residential building is specified to be 0.35 air changes per hour (ASHRAE, Standard 62, 1989). That is, 35 percent of the entire air contained in a residence should be replaced by fresh outdoor air every hour. If the ventilation requirement of a 2.7-m-high, 200-m2 residence is to be met entirely by a fan, determine the flow capacity in L/min of the fan

Answer 1

3150 L/min

Step-by-step explanation:

The volume of the room is the product of the height of the room and its area. It is given as:

Volume (V) = height (h) × Area (A)

V = h × A

Height = 2.7 m, Area = 200 m². Hence:

V = h × A = 2.7 × 200 = 540 m³

The flow capacity (
`\dot {V}`) is given by

`\dot {V}=ACH*Volume\ of\ room`

ACH = air changes per hour = 0.35

`\dot {V}=ACH*Volume\ of\ room\\\\\dot {V}=0.35*540\\\\\dot {V}=189\ m^3/h`

But 1 m³ = 1000 L, 1 hr = 60 min

`\dot{V}=189\ m^3/h=(189\ m^3*(1000\ L)/(1\ m^3) )/(1\ h*(60\ min)/(1\ h) ) =3150\ L/min\\\\\dot{V}=3150 \ L/min`