Every dust collector gets a score from 0 to 100% built from five factors, which maps onto the 5-point rating shown on the site (a 0% score would be 1.5 stars; a perfect score, 5). Each factor is scored against fixed reference points, not against the other products in the list, so adding a new model never moves another model’s rating. Collectors are grouped by build, single-stage and cyclone; value and airflow use a separate scale for each build, and the other factors use one scale for both.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per cfm of maximum airflow | 30% |
| Airflow | maximum airflow | 15% |
| Suction | maximum static pressure | 10% |
| Filtration | finest particle the filter catches | 25% |
| Warranty | warranty length | 20% |
Where the numbers come from
Airflow, static pressure, filter rating, motor size, capacity and warranty come from the maker’s product page, spec sheet or manual. Makers measure airflow in different ways, most with no hose attached, so the product page notes how a maker measured it when the maker says. Prices are checked at Amazon and the maker’s own store, and the lowest is used.
The factors
Value is the current price divided by the maximum airflow, on a log scale, so halving the price per cfm always counts the same. For single-stage collectors $1.50 per cfm scores zero and $0.25 full marks; for cyclones $3 per cfm scores zero and $0.60 full marks.
Airflow is the maker’s maximum airflow. For single-stage collectors 500 cfm scores zero and 1,500 cfm full marks; for cyclones 600 cfm scores zero and 1,700 cfm full marks.
Suction is the maker’s maximum static pressure: 5 in of water scores zero and 14 in full marks. Static pressure decides how much airflow survives a long hose or duct run.
Filtration is the finest particle the filter that ships with the collector is rated to catch, on a log scale: 30 micron scores zero and 0.3 micron full marks. A filter sold as an extra doesn’t count.
Warranty is the maker’s warranty: 1 year scores zero and 5 years full marks.
What isn’t scored
Motor size, the filter’s efficiency percentage, filter type, inlet size, collection capacity, voltage, noise, a remote control and weight are listed but not scored.
Missing data
If a figure isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated. The exception is warranty: a maker that doesn’t publish one gets no warranty counted, so that factor scores zero, the same as the shortest warranty on the scale, and is marked estimated.
Ties and discontinued models
Products are ranked by score within each group. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.