I was recently contacted by an environmental official from a Mid-Atlantic state asking about putting idling and retrofit requirements on construction equipment used in State funded construction projects. He wanted to find out the percentage of time a typical piece of construction equipment idles during a normal workday. After consultation with other industry experts who recently tackled this issue in California, here’s what I told him:
We’ve looked at doing something similar in California and decided that it’s a bad idea to assign those types of restrictions to specific types of projects because there is no “one-size-fits-all” answer to the idling issue or the issue of putting control devices on. It’s very equipment and operation specific. The trend is to require an idling policy, rather than set absolute limits to allow flexibility in recognition of the different operating environments. Also, union contracts may also influence the operation and idling of machinery. In addition, cranes idle all day just to perform a few lifts, but you can’t stop and start them between motions.
Further, we’re learning the hard way that VDECS (Verified Diesel Emissions Control Systems, like Huss) technology is not ready for prime time in large off road engines. I would encourage you to look towards diesel oxidation catalysts (DOCs) and away from VDECS if at all possible. DOCs are much less expensive and generally work reasonably well because they don’t have a regeneration issue. Our air scientists, Justice & Associates (www.justiceassociates.com) have described a few of their asphalt clients who have DOCs on their loaders and they operate the loaders basically without noticing the DOCs.