When a business owner decides to invest thousands of dollars in a compressed air system, he is going to be looking for quality, dependability, and a manufacturer he can trust over the long haul. While Ingersoll Rand has had its ups and downs as a company, it has been in the compressed air system business for over a century, and it pretty much has the market cornered on portable air compressors. For the past few decades, it has dominated portable air compressor sales by 40 and 50 percent. The three other largest sellers of portable air compressors--Atlas Copco, Sullair and Sullivan