Wet dry vacuums handle a wider range of cleanup tasks than regular vacuum cleaners; they are used to vacuum liquids and collect dust and debris in workshops and garages and on jobsites. Note that the term "Shop-Vac" is a brand name; in the same way that "Kleenex" and "Xerox" have morphed into generic terms, "Shop-Vac" has also become an umbrella term for wet dry vacuums. Basic wet dry vacs are useful for general cleanup around the house, but woodworkers and contractors often prefer more expensive pro-grade shop vacuums. This type of vacuum is tool-triggered, meaning there's an onboard outlet you can plug power tools into, and vacuum and tool(s) are activated simultaneously.
For tests of general-use wet dry vacs, we found the best review at ConsumerReports.org, where editors test 23 models ranging in size from 2 to 20 gallons; ratings are based on rigorous objective tests. A review at Popular Mechanics provides more details on some of the same shop vacuums, but it tests just six models, only one of which is a tool-triggered vac.
We found the most recent comparison tests of tool-triggered wet dry vacs at Fine Woodworking and This Old House Magazine. The results of vacuum comparison tests are also discussed in older reviews in Wood magazine, Fine Homebuilding, the Journal of Light Construction and Tools of the Trade magazine.
In addition to these comparisons, we found in-depth single-product reviews of wet dry vacs in woodworking publications and at the websites of individual woodworkers. We also studied owner reviews published at Amazon.com, HomeDepot.com, Sears.com and several other sites. Owner reviews often include details missing from the big comparison tests, along with a longer-term perspective on durability.