VIAIR Portable Air Compressor FAQ’s

Q: What is CFM?
A: The notation CFM (Cubic Feet per Minute) refers to a volume of air produced by the air compressor at a given pressure or PSI (Pound per Square Inch)

Q: What is Duty Cycle?
A: A compressor’s duty cycle determines the percentage of run time in a full cycle. A full cycle is determined by adding the compressor run time to its rest time.

Q: Does a compressor that has 100% Duty Cycle mean that I can run the compressor all the time? Can I run a 100% duty cycle compressor 24 hours a day?
A: No, you’ve got to remember that duty cycle is rated at 100psi, at an ambient temperature of 72F, but certainly a 100% duty cycle compressor can run for much longer periods of time than a 30% duty compressor under the same conditions. A rule of thumb with compressors is that the lower the duty cycle, the faster that compressor performs. However, a 33% duty cycle compressor will not be able to run for as long a period of time as a 100% duty cycle compressor can under optimal conditions.

Q: Does a new compressor have to be broken in?
A: No, they do not. Typically after an install, you should power up the system to whatever the cut-off pressure is and check for any leaks that may be present. (Only applicable to onboard air systems, not portable compressors).

Q: How do you check for leaks in an onboard air system?
A: You can check for leaks by putting soap and water solution where the fitting connections are. If there are bubbles present that grow in size, then there are leaks.

Q: Does it matter where I install my compressors on my vehicle?
A: This depends on several factors such as available space, whether or not the compressor is of a sealed or vented type, as well as personal preference and aesthetics. Make sure to utilize the rubber insulators to keep vibration and noise to a minimum.

Q: How can I tell whether the compressor is sealed or non-sealed?
A: Manufacturers will normally specify if a compressor is sealed against moisture and dust, and in many cases, you can tell the difference by simply inspecting the compressor. If you see vents, cracks, or holes in the motor housing, then the compressor is not sealed and must be kept away from dust and moisture.

Q: Why is it important to have a sealed and moisture-resistant compressor?
A: The preference of a sealed-type compressor is due to the fact that in mobile pneumatics, compressors are likely to be exposed to the elements.

Q: Is it possible to mount the compressor sideways? Must it be mounted with the cylinder upright?
A: Yes, you can mount our compressors in any direction or position because they are oil-less. The only position we do not recommend is an upside-down mount, since heat tends to travel upward. Never try to lubricate any VIAIR compressor. All VIAIR compressors come with permanently lubricated bearings, and have anodized aluminum cylinder walls for a superior seal and excellent internal wear resistance.

Q: If I mount my compressor sideways, like on the frame rail of my truck, is there anything I should be careful of when doing this?
A: If you mount your compressor sideways to the frame rail, you should periodically check to make sure that your compressor is mounted securely. Use a thread-locking compound to keep the screws from backing off and causing the compressor to be mounted loosely.

Q: Is it possible to hook up more than one compressor to a single pressure switch?
A: Yes, it is possible to use one pressure switch on more than one compressor. You should always run a relay if you want to hook up multiple compressors to a single switch. You should check the amp draw on the switch first, and then you’ll know how many compressors you can hook up to one switch.

Q: Can I use an adjustable pressure switch with my compressor?
A: We don’t recommend that you use adjustable pressure switches with any VIAIR compressor. If you use an adjustable pressure switch, you can set the pressure switch higher than the maximum pressure that is rated for your compressor, or you may exceed the maximum rated working pressure for your air supply tank. Doing so will immediately void your warranty, not to mention, it is dangerous.

Q: Is the amp draw of the compressor something I need to be concerned with?
A: Yes, the lower the amp draw, the better the compressor is. Always determine the maximum working amperage of a compressor or onboard air system compared to the ability of your vehicle to provide said amperage. Always keep your vehicle’s engine running while operating compressors in order to keep current flow maximized and performance optimal.