ASHRAE 241 Clean Air Delivery Rate (CADR) Calculator

Use this calculator to calculate the total Clean Air Delivery Rate (CADR) required for an indoor space according to the guidelines set in ASHRAE 241.

You will need the following information to calculate the CADR:

1. Occupancy Type. This indicates the type of indoor space, for example, a restaurant, school, retail location, transportation hub, etc.
2. Number of Occupants. This indicates the number of occupants in the indoor space. We recommend setting the number of occupants to the maximum capacity of the indoor space you’re calculating for.

The result provided by the calculator will tell you the total CADR required to effectively control the spread of airborne diseases indoors. The guidelines are based on reducing the possibility of infection to 0.1% when an occupant spends 1 hour in an indoor space, and that 1% of the community is infectious with an airborne disease (such as SARS-Cov2/COVID-19 and influenza).

With the total CADR, you will be able to figure out how many room air purifier(s) you need for the space, as well as the minimum speed to set them to.

For example, if the total CADR required is 1,400 m³/h, you will need two AirFanta 3Pro units at speed setting 6 (702 m³/h CADR per unit), or three AirFanta 3Pro units at speed setting 4 (545 m³/h CADR per unit).

Looking for a high performance room air purifier at an affordable price? Check out the AirFanta 3Pro, the most cost-effective room air purifier in Singapore available for just S$195! It packs an impressive 702 m³/h CADR at a fraction of the cost of other brands. With a staggering 3.60 m³/h of Clean Air per dollar, it gives you 3 – 8 times more clean air than other products in the market.