The size of the pet air purifier you need for your home depends on several factors, including the size of your home, the number of pets you have, and the severity of your pet allergies or respiratory issues.
As a general rule, for a small room or area where you keep your pet, a small air purifier may be sufficient. For larger rooms or open-concept spaces, you will need a larger air purifier with a higher clean air delivery rate (CADR).
To determine the appropriate size for your pet’s air purifier, you should consider the square footage of the room or area where the purifier will be used, as well as the CADR rating of the air purifier. The CADR rating indicates the volume of air that the purifier can clean in a given amount of time.
As a rough estimate, for a room of up to 300 square feet, a purifier with a CADR rating of 150-200 should be sufficient. For larger spaces of up to 500 square feet, a purifier with a CADR rating of 300-350 may be more appropriate. However, these are general guidelines and the specific needs of your home and pets should be taken into consideration before selecting an air purifier.
Here’s a helpful table The chart below assumes that your ceiling height is the standard 8 feet. It shows the recommended sizes of air purifiers for achieving 2 air changes per hour (ACH) and 5 ACH. Note that if you have a large room that requires an air purifier with a clean air delivery rate (CADR) of 500 cubic feet per minute (CFM) or more, please refer to the note below the chart for appropriate sizes.
| SQ Footage | Pet Purifier Size (CADR At 2 ACH) | Pet Purifier Size (CADR At 5 ACH) |
| 100 | 27 CFM | 67 CFM |
| 150 | 40 CFM | 100 CFM |
| 200 | 53 CFM | 133 CFM |
| 250 | 67 CFM | 167 CFM |
| 300 | 80 CFM | 200 CFM |
| 350 | 93 CFM | 233 CFM |
| 400 | 107 CFM | 267 CFM |
| 450 | 120 CFM | 300 CFM |
| 500 | 133 CFM | 333 CFM |
| 600 | 160 CFM | 400 CFM |
| 700 | 187 CFM | 467 CFM |
| 800 | 213 CFM | 533 CFM |
| 900 | 240 CFM | 600 CFM |
| 1000 | 267 CFM | 667 CFM |
| 1100 | 293 CFM | 733 CFM |
| 1200 | 320 CFM | 800 CFM |
| 1300 | 347 CFM | 867 CFM |
How To Calculate What Size Air Purifier You Need?
The size of the air purifier is given by CADR rating. We would be talking about 100 CFM, 200 CFM, 300 CFM air purifiers, for example. Most manufacturers don’t include the airflow in the specification sheet, or even in the unit name.
Example: Coway Mega 400 is so named because it has a 400 CFM CADR rating. Similarly, Honeywell HPA300 gets its name by having a 300 CFM CADR rating.
To calculate the size of air purifier we need, we will use this equation:
Size Of Air Purifier (In CADR Rating) = (Area × Height × ACH) / 60
Quick example: Let’s say we have a 1000 sq ft home with an 8 ft ceiling height and would an air purifier big enough to ensure 2 ACH. What size air purifier do we need for a 1000 sq ft home? Here’s how we can use the air purifier size formula to calculate that:
Size Of Air Purifier (1000 Sq Ft) = (1000 Sq Ft × 8 Ft × 2 ACH) / 60 = 267 CFM (CADR Rating)
Do you have more questions about what size purifier you need? Drop the team a line, and we can further help you.
