Referring to reasonable usage of building energy, protection for outside air environment in OA (fresh air) inlet and outside noise environment on the side of main air port, three restrictions were put forward as follows, (1) whole building ventilation volume restriction which should meet the upper limit of reasonable building energy consumption criterion [1] ; (2) maximum EA (exhaust air) volume restriction on the side of main air port to protect the air quality of the OA inlet on the side of main air port, according to the calculation equation of the EA volume mixing into OA of main air port [2]; (3) maximum ventilation volume restriction on the side of main air port for ensuring the outside noise meeting national noise standard, according to the calculation equation of the air port quantity and whole air volume of the main air port [3.4]. It was stressed that the maximum air volume of whole building ventilation design should meet the above three restrictions, which was essential for reasonable usage of building energy, protection for outside air environment in OA inlet and outside noise environment on the side of main air port.
