// ASHRAE 62.1 Ventilation Calculation Method
The outdoor airflow required (Vbz) is based on people-related sources and area-related sources. The equation for the calculation of Vbz is as follows:
Vbz = Rp * Pz + Ra * Az
Where:
Rp (Unit: CFM/person or L/s/person) = Outdoor airflow rate required per person as determined from Table 6.2.2.1
Pz = Number of people in the ventilation zone during use. analysis.tool calculates this number based on the occupant density and the floor area of the project.
Ra (Unit: CFM/ft2 or L/s/m2) = Outdoor airflow rate required per unit area as determined from Table 6.2.2.1
Az (Unit: ft2 or m2) = Net occupiable floor area of the ventilation zone.
The outdoor airflow rate Vbz has the unit of CFM when IP system is selected and L/s when the SI system is selected.
// California Title 24 Ventilation Calculation Method
The outdoor airflow rate to the zone (Vz) is determined according to the following equations:
Vz = Ra * Az (Equation 120.1-F)
Where:
Ra (Unit: CFM/ft2 or L/s/m2) = Outdoor airflow rate required per unit area as determined from Table 120.1-A.
Az (Unit: ft2 or m2) = Net occupiable floor area of the ventilation zone.
Vz = Rp * Pz (Equation 120.1-G)
Where:
Rp = 15 CFM of outdoor airflow per person
Pz = Expected number of occupants.
The maximum value from equations 120.1-F and 120.1-G is considered for outdoor airflow rate (Vz). Typically, the equation 120.1-F yields highest value so analysis.tool refer that equation for the calculation of outdoor airflow rates.
It can be easily edited according to the project from 'Building System' tab.
//United Kingdom National Calculation Methodology (NCM) Ventilation Calculation Method
The NCM Activity Database contains the l/s/p value for different building types. analysis.tool refers those values along with occupant density and the total floor area to calculate total L/s value for the project.
//Australia National Construction Code (NCC) 2019 Ventilation Calculation Method
The minimum amount of introduced outdoor air for the system (Qf) shall be calculated as the greater of the area-based minimum and the occupancy-based minimum as follows:
(a) Area-based minimum:
Qf = (A * 0.35) L/s.m2
Where:
A (Unit: ft2 or m2) = Net occupiable floor area of the ventilation zone.
(b) Occupancy-based minimum:
Qf = (n * qf)
Where:
qf (Unit: CFM/person or L/s/person) = Outdoor airflow rate required per person as determined from AS 1668.2 standard.
n = Expected number of occupants.
