Air purifier filter cost per year: the running cost that matters most
With an air purifier, the unit is the smaller part of the bill. Replacement filters are the recurring cost, so convert them to a yearly figure.
Formula
Yearly filter cost = filter price / replacement interval in months x 12
Worked example
| Model A | Model B | |
|---|---|---|
| Unit price | $400 | $550 |
| Filter set | $50 | $30 |
| Replacement interval | 6 months | 12 months |
| Yearly filter cost | $100 | $30 |
| Five-year total | $400 + $500 = $900 | $550 + $150 = $700 |
Model B costs $150 more to buy but is $200 cheaper over five years. Actual filter life depends on air quality and hours of use, so treat the maker's interval as a starting point.
Reading the specifications
- Clean air delivery ratings and room-size claims use test conditions that differ by brand
- Match capacity to your room and keep doors closed when running it
- Check filter types and how the replacement reminder works
Electricity
A 30 W unit running 12 hours a day uses 0.03 x 12 x 30 = 10.8 kWh a month, about $1.84 at $0.17 per kWh. Electricity is small next to filters.