Skip to Content
Healthy Buildings

Portable Air Cleaner Sizing Tool (PACS)

This Harvard Healthy Buildings Portable Air Cleaner Sizing tool (PACS) was developed by the Harvard Healthy Buildings program to help people select an appropriately-sized portable air cleaner for indoor spaces. Users input their “clean air” target (measured in units of equivalent air changes per hour, or ACHe) and information about the size of the room. The calculator returns the “clean air delivery rate” (CADR) the user should look for from the air cleaner manufacturer. The tool can also be used in the reverse. The user inputs the CADR on a portable air cleaner they have or are considering, and the calculator returns the room size.

Limitations: Portable air cleaning is only one of several methods for reducing the concentration of airborne particles indoors, including those from the respiratory tract that may contain infectious viruses or bacteria or those from outdoor or indoor pollution. For more information on portable air cleaners, please review our report on this topic.

1. Input Type

Calculate clean air delivery rate (CADR)

Determine the air cleaner(s) required in a room to reach a target equivalent air exchange rate (eACH).

Calculate maximum room size

Find the largest room acceptable for a given clean air delivery rate (CADR), to reach a target equivalent air exchange rate (eACH).

Room Size

Clean Air Delivery Rate

Imperial
Metric
ft2
m2
CFM
m3/hr
Note: Find the CADR from the air cleaner manufacturer in cubic feet per minute, or CFM. If multiple numbers are listed, use the one for "dust". Note: Find the CADR from the air cleaner manufacturer in cubic meters per hour, or m3/hr. If multiple numbers are listed, use the one for "dust".
ft.
m.

2. Room Ventilation Levels

ACH
Reset value

3. Goal Air Exchanges Per Hour

Target equivalent air exchanges per hour

eACH
Ideal (6 ACH) Excellent (5-6 ACH) Good (4-5 ACH) Minimum (3-4 ACH) Low (< 3 ACH)
Ideal (6 ACH) Excellent (5-6 ACH) Good (4-5 ACH)
Minimum (3-4 ACH) Low (< 3 ACH)

Result

Configure the settings and then click the button below to calculate.

Translate