Russell Ashcroft, PE, Principal Engineer, Southland Engineering, Tempe, Ariz.
Mike Barbes, PE, LC, Senior Electrical Engineer, AECOM, Atlanta
Reinhard Hanselka, PhD, Director of Code Compliance, CRB, Kansas City, Mo.
Marcin Jakubowski, Senior Mechanical Engineer, RTM Engineering Consultants, Orlando, Fla.
Eric M. Roeder, PE, Project Manager, Security & Fire Protection, JENSEN HUGHES, Arlington, Va.
Sunondo Roy, PE, LEED AP BD+C, Vice President, CCJM Engineers Ltd., Chicago
CSE: Describe a recent electrical/power system challenge you encountered when working on projects in industrial, manufacturing, and warehouse buildings.
Roy: One client has very unique, specialized proprietary electrical equipment built and tested in-house. There really aren’t any other products like it that we’ve seen before. As such, our electrical engineers have had to study the equipment in detail to integrate new power distribution with the equipment and ensure NEC requirements are being met. Fortunately, the equipment is listed to minimize permit-review complications.
Barbes: On a recent large (more than 1 million-sq-ft) warehouse project, there was discussion that the usage may change during the kickoff meeting. The building was originally designed as a speculative warehouse space; however, after the design was completed, a tenant wanted to lease the entire space as a manufacturing facility. This change was initially discussed as a “possibility.” The challenge was to complete the design as a warehouse, with completed IECC calculations, but allow the building to develop into a task-specific manufacturing facility. It was a creative solution to design the lighting layout as a warehouse and then “blend” new lighting fixtures, control devices, and branch circuits into the building to transform the lighting into a manufacturing facility.
Ashcroft: Projects to retrofit an existing facility have an increased probability of being limited to the amount of power available for the requested changes. Whether the existing service entrance section is reaching capacity or the existing electric utility is at capacity, which limits what the existing facility may be able to do. Often, the owner does not realize that existing systems are maxed out. The sooner this issue can be found, the better to begin the process of optimizing the project.
CSE: How do you work with the architect, owner, and other project team members to make the electrical/power system both flexible and sustainable?
Ashcroft: Regular team meetings are required to ensure that the electrical system meets the needs of the project for now and in the future. It also is necessary during the design process to look at multiple possible options to accomplish the design requirements and provide flexible and sustainable alternatives in the future. Too often, engineers may find a way to fit the needs of a current project, but in doing so they may compromise future expansion or sustainability. Fixes then become even more expensive and disruptive.
CSE: What types of smart grid or microgrid capabilities are owners demanding, and how have you served these needs? Are there any issues unique to these industrial, manufacturing, and warehouse projects?
Ashcroft: For utility plans, “net zero” is now the hot catchphrase. Most of these capabilities are trying to be met by solar or wind turbine alternatives. Microgrid technologies, such as onsite power generation, uninterruptible power supply systems, and even cogeneration systems, are being requested as possible microgrid opportunities.
Barbes: We are working on some projects, mostly for energy storage. I think most owners are receptive to the idea(s), but the majority of these options are costly.
CSE: Describe a recent standby, emergency, or backup power system you designed, and its challenges and solutions.
Barbes: A recent design was for a refrigerated warehouse project, with both refrigerated and freezer sections. Due to the product-replacement costs, the owner requested diesel generator backup power including supplemental temporary generator backup power. The owner made arrangements with a local generator distributor to provide onsite temporary generators in the event that if the project generators failed, backup power would still be available in a relatively short period of time.
Ashcroft: We just completed the design of an additional backup generator to an existing research and development facility. The challenge for us was understanding the full real load currently backed up as well as what was remaining in the facility that was of a critical nature, which would need to be added to the backup system. The owner originally was not aware of the systems that were not already on backup power, nor the extent of work required to make the changes needed to provide the backup power. Ultimately, it was necessary to have multiple meetings with the owner’s site representatives to determine how to reduce the impacts and costs of the project while meeting the needs of backup power.
CSE: How have the needs of lights been integrated with other systems in industrial, manufacturing, and warehouse structures, such as an HVAC system?
Barbes: We have not seen any requests for such comingling of systems. My suspicion is that there is little to be gained since most such facilities are 24/7 operations. Along with low-lighting power densities, there would be few financial benefits.
Ashcroft: One item I have tried to accomplish on all major mechanical systems and lighting is to work with the engineers and vendors of the HVAC equipment suppliers to have the light fixtures (internal and external) properly located and circuited separately, so that they can be switched and operated while main power to the unit is turned off for maintenance or during an outage.
CSE: Describe a lighting control or addressable lighting project you’ve completed in an industrial, manufacturing, or warehouse building. What were the challenges and solutions?
Barbes: Per the owner’s request, LED lighting fixtures were furnished with integral occupancy sensors and installed at a 30-ft mounting height. The warehouse had stacking racks on each row and was operated with forklifts; the intent was to have the lights turn on “as needed” by the forklift travel. In reality, the integral occupancy-sensor control created somewhat of a “strobing” effect. As a lesson learned, the lighting controls were revised to control individual rows in lieu of individual fixtures. There was no financial benefit to the integral occupancy sensors, but the LED lighting source was the only sustainable lighting option.
CSE: What new or unique high-bay or other lighting systems are being specified into industrial, manufacturing, and warehouse projects? Describe the design.
Ashcroft: The typical industrial facility used to be designed with either high-density discharge or multiple-ballast fluorescent fixtures. Due to the need for more energy-efficient lighting, newly designed lighting has switched to LED for most applications within these types of buildings. This also allows for greater control of lighting bandwidths and colors for applications that may be harmed by UV light from the other sources.
Barbes: Most every manufacturing or warehouse project is going with LED lighting due to their long “lamp” life. On a few projects, we were asked to design the permanent lighting so that it could be used for construction purposes, which had a few challenges but did offer some cost savings.