1) The two-story office building has 36,000 ft³ of office space. Due to cracks around

windows and doors, the air leaks in on the windward side of the building and exits on the

leeward side. Tests were conducted on the building for energy efficiency when the

outdoor temperature was 15°F. The inside was at 70°F. The infiltration rate due to cracks

was 75 ft³/min and infiltration due to door openings was 50 ft³/min.

a) What is the volumetric flow rate of air exiting the building assuming steady state,

air as an ideal gas and no significant pressure difference between the inside and

outside of the building?

Determine the number of building air volume changes per hour.


c) If you need to meet the CDC guidance for airborne contaminant removal at 2

ACH, do you need to change the ventilation for the building?