Filters and running costs
Quick answer
Filters usually cost more than the machine. Across the 16 machines here with a matching replacement filter, the filters account for up to 62 percent of the five year cost at a twelve month replacement interval. The sticker price is the smaller half of the decision.
MERV is a standard, defined by ASHRAE 52.2. The replacement intervals used below are hypotheses, shown at six, nine and twelve months rather than assumed.
| Machine | Unit price | Filter | Five year total | Filters as a share |
|---|---|---|---|---|
| Afloia | $59.97 | $23.98 | $155.89 | 62 percent |
| DREO | $59.97 | $22.99 | $151.93 | 61 percent |
| MOOKA | $46.98 | $17.98 | $118.90 | 60 percent |
| Clorox | $59.95 | $19.66 | $138.59 | 57 percent |
| Winix | $79.99 | $22.99 | $171.95 | 53 percent |
| GermGuardian | $80.74 | $19.88 | $160.26 | 50 percent |
| Levoit | $189.99 | $32.88 | $321.51 | 41 percent |
| Levoit | $259.99 | $41.99 | $427.95 | 39 percent |
| HATHASPACE | $199.99 | $28.79 | $315.15 | 37 percent |
| Levoit | $167.96 | $24.99 | $267.92 | 37 percent |
| Winix | $179.99 | $26.99 | $287.95 | 37 percent |
| BLUEAIR | $349.00 | $49.99 | $548.96 | 36 percent |
| Medify Air | $249.99 | $34.99 | $389.95 | 36 percent |
| Shark | $159.95 | $21.37 | $245.43 | 35 percent |
| Instant | $199.99 | $24.99 | $299.95 | 33 percent |
| Coway | $218.50 | $23.99 | $314.46 | 31 percent |
Amazon Basics 20x20x1 Air Filter 6-Pack, MERV 11 AC Furnace Filters, Dust, Pet, Allergen Control, Electrostatic (Actual Size: 19.75 x 19.75 x.75)
A furnace filter works on the whole house whenever the blower runs, which is complementary to a portable machine rather than a replacement for one.
Check the size printed on the frame of the filter already in the return before ordering.
What the MERV scale means
MERV is defined by ASHRAE 52.2, and the rating a filter earns is its worst performance across three particle size bands rather than its best. That is what stops a filter advertising a headline figure it only reaches on the easiest particles.
- MERV 1 equipment protection
- MERV 2 equipment protection
- MERV 3 equipment protection
- MERV 4 equipment protection
- MERV 5 general dust
- MERV 6 general dust
- MERV 7 general dust
- MERV 8 general dust
- MERV 9 dander and fine dust
- MERV 10 dander and fine dust
- MERV 11 dander and fine dust
- MERV 12 smoke and fine particles
- MERV 13 smoke and fine particles
- MERV 14 commercial and hospital
- MERV 15 commercial and hospital
- MERV 16 commercial and hospital
Deciding between two ratings
Replacement filters
- Borgodf
Borgodf B-D02L/M05 Replacement Filter for MOOKA B-D02L & M05 Air Purifier
- HEPA claimed
- carbon stage
$17.98 Check pricePrices change often - Sinnya
12020 11020 HEPA Replacement Filter for Clorox Air Purifier 11020 & 11021
- HEPA claimed
$19.66 Check pricePrices change often - Cabiclean
Blue Pure Replacement Filter for Blueair 411, 411+, 411 Auto Air Purifier
- carbon stage
$19.89 Check pricePrices change often - Clorox
Clorox Tabletop Air Purifier True HEPA Replacement Filter, 200 Sq. Ft.
- HEPA claimed
$19.99 Check pricePrices change often - Borgodf
2 Pack HP102 Replacement Filter Compatible with Shark HP102 Air Purifier
- HEPA claimed
- carbon stage
$21.37 Check pricePrices change often
Common questions
Why do filters cost so much?
Because they are the part of the business model that repeats. A machine is sold once and its filters are sold for as long as it runs, so proprietary filters are where the margin sits. That is not an accusation, it is the shape of the category, and it is the reason to look up the filter price before buying rather than after.
What is the difference between MERV and HEPA?
They are different scales for different equipment. MERV, defined by ASHRAE 52.2, rates filters for ducted systems and runs from 1 to 16. True HEPA is defined as capturing 99.97 percent of particles at 0.3 micron and sits beyond the top of the MERV scale, in machines with their own fan sized for that resistance.
Can I put a MERV 13 filter in any furnace?
Not always. A denser filter raises static pressure, and a system that was not designed for it moves less air, which makes heating and cooling worse while the blower works harder. Check what the equipment manufacturer sanctions, and if you step up the rating, step up how often you change it at the same time.
Are third party replacement filters safe to use?
The risk is the seal rather than the media. Air takes the easiest path, so a filter that does not seat properly lets air bypass the media entirely and the machine keeps making noise while filtering very little. If you use one, look at how it sits in the housing rather than at the percentage on the box.
Does a washable pre-filter save money?
Yes, and it is the cheapest saving available. The pre-filter catches hair and coarse dust that would otherwise load the pleated stage, so washing it every few weeks keeps the expensive filter at the long end of its interval rather than the short one. It does not replace the main filter, and a pleated HEPA filter cannot be washed.