Compressors and generators supply much of the power on today's jobsites, so manufacturers' efforts to design and build environmentally friendly power sources go a long way toward ensuring cleaner and "greener" jobsites.

"Manufacturers are putting a great deal of effort into making equipment more environmentally friendly - and with compressors, that focus is primarily on noise reduction and fuel efficiency," says Chance Chartters, direct accounts manager, Mobilair, Kaeser Compressors.

As most are aware, EPA regulations for diesel engines have gotten much stricter over the past decade and are due to get tighter still in 2008 as Tier III/ Interim Tier IV regulations go into effect. According to Todd Howe, product marketing manager for generators at Doosan Infracore Portable Power (producer of the Ingersoll Rand brand), this presents a formidable challenge to manufacturers who aim to build energy efficient, quiet and compact compressors and generators.

For example, new EPA-compliant engines are not usually "drop-in" replacements for their predecessors, Howe points out. Often, the new engines mount differently and require different plumbing and wiring. As a result, the entire product can require a redesign to incorporate the new engine.

Added complexity
With each EPA Tier change, the engines run hotter, so the cooling systems get bigger, the machines themselves get louder and so on.