4.0 HP, 20.0 Gal, Sound Proof Cabinet, Auto Drain, Ultra Quiet Oil-Free Air Compressor - California Air | CAT-20040SPCAD

California Air Tools 20040SPCAD: 4 HP in a sound proof cabinet with auto drain

This is the 20040CAD compressor built into a sound proof cabinet on casters: the same twin 2 HP oil free pumps, 20 gallon tank, 10.6 CFM at 90 PSI and 125 PSI maximum, plus the factory EZ-1 automatic tank drain, with the noise knocked down to as low as 65 dB. Buy this one when the compressor has to live in the work area, not in a closet or outside: dental and medical offices, labs, cabinet and furniture shops, print shops, retail service bays and any indoor space where people are talking on the phone.

It will run impact wrenches, nailers, grinders, a tire machine and a mid size HVLP gun or DA sander in normal shop use. Treat it as a 70/30 duty machine rather than continuous duty; for all day sanding or two users pick the 60040CAD or a small rotary screw. The cabinet has exhaust fans, so leave 12 inches of clearance at the vents and do not box it into a corner.

Power is 220 volt single phase at 14 amps on a NEMA 6-15 plug; give it a dedicated 20 amp circuit. The auto drain discharges on a timer, so route the drain hose to a floor drain or a container. The whole unit weighs 230 lb and ships by freight, lift gate available. For painting or anything sensitive to water, add the RD-91503 refrigerated dryer and a filter regulator at the outlet. See the smaller 10020SPC cabinet unit, more California Air Tools compressors, and other 10 CFM and 125 PSI compressors.

Manufacturer description

CAT-20040SPCAD California Air Tools 4.0 HP 20 Gallon Ultra Quiet Oil-Free Air Compressor (Sound Proof Cabinet + Auto Drain Valve)

When you need real shop airflow but don’t want your compressor to dominate the building, the CAT-20040SPCAD delivers. This unit pairs a 20.0 gallon steel tank with an oil-free dual piston pump and a sound proof cabinet, giving you strong output for air tools and spray work while keeping noise and maintenance down. It’s built for garages, production spaces, and indoor shops where you want power you can live with.

Strong air delivery for demanding tools

The CAT-20040SPCAD is rated at 12.80 CFM @ 40 PSI and 10.60 CFM @ 90 PSI, with a maximum pressure of 125 PSI. That’s the kind of airflow that supports continuous work, impact tools, sanders, blow-offs, and many spray applications, without constantly waiting for tank recovery.

Ultra-quiet by design: sound proof cabinet + cooling airflow

A big reason people choose this model is the cabinet. The compressor components live inside a sound proof enclosure designed to reduce perceived noise while still managing heat. The cabinet includes:

• Acoustic sound-dampening material to cut sound transmission
• Multiple exhaust fans to move heat out of the enclosure
• Two latching doors for convenient access when you need it
• Four caster wheels so you can reposition the unit in a shop

Noise is listed as low as 65 dB, which is dramatically easier to tolerate than typical high-output shop compressors.

Oil-free dual piston pump = cleaner air and less maintenance

This compressor uses an oil-free dual piston system, meaning:

• No oil changes
• Reduced risk of oil carryover in the air stream
• Simplified ownership (especially for shops that don’t want extra maintenance tasks)

Power is driven by twin 2.0 HP motors running at 1680 RPM, helping keep operation quieter and smoother while supporting longer duty cycles.

Auto Drain Valve: stop babysitting the tank

Moisture buildup is unavoidable, especially in humid conditions or high-use shops. The factory-installed EZ-1-2321 Auto Drain Valve helps handle that automatically. It uses timed draining so you can set how often and how long the valve opens (with a factory preset to get you started). The result: less water sitting in the tank, fewer “I forgot to drain it” moments, and a cleaner day-to-day workflow.

Features that matter in real use

• Condor pressure switch for reliable control
• Thermal overload protector for motor protection
• Easy Start Valve to reduce starting load
• Two pressure gauges plus an output regulator
• Female industrial push-to-connect quick connector for fast hookup
• Includes (4) air filters

Ideal for

1. Indoor workshops where noise is a problem
2. Automotive and fabrication spaces running air tools regularly
3. Woodworking and finishing setups that benefit from oil-free air
4. Busy garages that want strong output without constant maintenance

Specs at a glance

• Model: CAT-20040SPCAD
• Tank: 20.0 gal steel
• Airflow: 12.80 CFM @ 40 PSI / 10.60 CFM @ 90 PSI
• Max pressure: 125 PSI
• Power: 220V / 60Hz / single phase
• Current draw: 14 amps
• Plug: NEMA 6-15P (fits 6-15R or 6-20R)
• Dimensions: 19" x 38" x 33"
• Weight: 230 lb
• Duty cycle: 70/30
• Noise: as low as 65 dB

If you want a serious compressor that doesn’t sound like a helicopter in your workspace, and you like the idea of oil-free operation, a sound-managed cabinet, and an automatic drain system, the CAT-20040SPCAD is a smart, long-term shop upgrade.