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A 6.5 peak HP shop vac runs on 1,440 watts
Shop vac listings lead with peak horsepower. The makers' own fine print says the motor does not run at that number in use. The math agrees: 6.5 HP would be about 4,849 watts, and a 15 amp household outlet supplies 1,800 at most. On the seven vacs here, the watts drawn at the wall are 29 to 48 percent of what the peak HP claim implies. Buy by the numbers that describe the job: airflow, water lift, hose diameter, filter and tank.
Check a listing's peak HP Match a vac to your job See the 7 picks
Peak HP reality check
An estimate. One horsepower is 746 watts. Amps times volts is the power the vac draws from the wall, and some of that is lost as heat and noise, so the real output is lower still. If a listing gives watts but no amps, divide the watts by 120 and enter that.
Guides
Start here
- The 7 best wet/dry shop vacs, by the numbers that matter
Seven shop vacs from CRAFTSMAN, Vacmaster, DEWALT, Stanley and Armor All, compared by real watts, stated CFM and water lift, hose diameter, filters and tank.
- Peak HP vs real watts: check any shop vac listing
Enter the peak HP and amps from any shop vac listing. See the watts it really draws, the share of the HP claim that is, and the math behind it.
- What size shop vac do you need for the job?
Pick your main job, from car cleaning to a flooded basement. See the tank class, hose diameter and filter it calls for, and which picks fit.
What listings lead with
- CFM, water lift and air watts, in plain words
CFM is airflow, water lift is suction, air watts combine them. What each number means in maker terms, and which of seven listings state them.
- Tank gallons are not the water you can pick up
Tank gallons are the full volume, not what you can pick up. How the float works, what a full tank weighs, why a drain port matters, and flood safety.
What decides the job
- 1-1/4, 1-7/8 or 2-1/2 inch: which hose size do you want?
Shop vac hoses come in 1-1/4, 1-1/2, 1-7/8 and 2-1/2 inch systems. What each size suits, how to measure yours, and which tools fit which vac.
- The right shop vac filter for drywall dust, debris and water
Which shop vac filter to use for drywall dust, cold ashes, general debris and water, why a HEPA filter does not make a HEPA vacuum, and what ships in each box.
Safety
- What you should never pick up with a shop vac
Hot ashes, flammable liquids, and hazardous dust like asbestos and lead do not belong in a shop vac. What the makers and fire and health agencies say.