CET4-20 Air Compressor
This air compressor from Bosch has a speedy impact of noise recovery time
Generally, I rely on big, noisy, gas-powered air compressors for my framing jobs because I can keep them running (or better said, they keep running regardless of me). When doing remodels or additions, though, I run smaller electric compressors to keep the noise level down for the homeowners and their neighbors. I was booked with three months’ worth of such jobs when Fine Homebuilding sent me Bosch’s CET4-20 ($310).
While unpacking this vertical twin-tank unit, I noticed a generally high level of build quality. No loose parts or pieces jutted out from the unit at risk of being knocked off. All the vulnerable components were nestled between the two tanks, where they are easily accessible yet highly protected.
Despite a well-placed, comfortable rubber handle, lugging this 4-gal., 73-lb. beast around is a chore. My crew members weren’t exactly lining up to carry this compressor-shaped boat anchor every morning. Experience tells me, though, that a light compressor is generally indicative of cheap components, which in professional-grade tools cost far more money than they save.
At 80 db., this compressor isn’t quiet, but compared to other units I’ve worked around, it’s not bad. One thing that helps to ease the impact of the noise is the unit’s speedy recovery time. It goes from empty to 125 psi in 48 seconds and has an in-use recovery time of just 12 seconds when we’re running two nailers at 115 psi each. The compressor is rated 4.2 cfm at 100 psi.
Heavy rubber feet and a highly effective shock-absorbing system on the frame keep vibrations fairly well contained. While the compressor was resting on a wood-frame floor, I was able to use a tripod-mounted line laser about 60 ft. away with little disruption.
Bottom line: This is a well-built unit that must have been engineered by someone who’d broken a few compressors and learned from those mistakes. After daily use on dusty framing sites, it has changed my mind about the capabilities and life expectancy of electric compressors. If an electric compressor can survive three months with me, it will probably serve anyone else for years.