**// 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. cove.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 cove.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. **Cove.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.