Designing labs, research buildings: Electrical, power systems
Labs and research facilities house sensitive equipment and must maintain very rigid standards. Electrical and power systems are of key importance.
Nedzib Biberic, PE, LEED BD+C, Mechanical Engineer, PAE Consulting Engineers, Portland, Ore.
Michael Chow, PE, CxA, LEED AP BD+C, Member/Owner, Metro CD Engineering LLC, Powell, Ohio
David S. Crutchfield, PE, LEED AP, Division Manager, RMF Engineering, Baltimore
Dave Linamen, PE, LEED AP, CEM, Vice President, Stantec, Edmonton, Alberta
Jay Ramirez, Senior Vice President, ESD Global, Chicago
CSE: What’s the one factor most commonly overlooked in electrical and power systems in laboratories?
Chow: Most laboratory renovations projects require more power than what was used for the existing laboratory. This is typically due to ventilation requirements requiring larger fume hoods along with other increased electrical loads. Many renovation projects require upgrading the electrical systems, and that may impact the project’s budget.
Crutchfield: We have seen that various labs that use older testing equipment (40+ years) that was originally slated to operate on 240 V only either underperforms when connected to 208 V or burns out. In renovation work, surveying this old equipment so that we can properly connect it is critical to the performance of the equipment and the lab relying on it.
CSE: How have sustainability requirements affected how you approach electrical systems?
Crutchfield: Beyond the obvious daylighting and occupancy controls, we now see a desire among owners for power that is from renewable sources or generated on-site. On-site generation tends to be more of a showcase for labs as the plug loads we see for the lab equipment generally makes total on-site power generation impractical.
Chow: Typical laboratories consume significantly more energy per square foot compared to a typical office building. Some ways to save electrical usage include: providing a lower ambient light level coupled with task lighting versus using a common 100 foot-candle level for the entire space, and use of occupancy sensors and daylight sensors to automatically turn off and/or dim artificial lighting. CO2 sensors can also save energy by reducing the amount of ventilation required when the space is unoccupied.
CSE: When commissioning electrical/power systems in labs, what issues do you face?
Chow: Issues can arise if the commissioning authority is not contracted or engaged until the construction phase. Problems may arise if the design engineer has electrical specifications that were used for bidding that do not include adequate commissioning specifications. For example, an electrical contractor may be responsible for certain types of testing (e.g., power quality) for witness by the commissioning agent. An issue can arise if the commissioning agent has a functional test that is required but the electrical contractor did not have this test in its bid. Costly change orders and disruptions to the project schedule can result if commissioning is not incorporated early in the design phase.
Crutchfield: The most common thing we see is the coordination of the non-emergency motor starting protocols and the emergency motor starting protocols when under generator power. Staggered starting (steps) of large motors to lessen the inrush current is often necessary but many times overlooked in the control sequences, and all the motors attempt to start simultaneously. A proper control sequence to bring motors back on line in steps can alleviate this problem of overloading the generator or simply not having enough power to start the motor during generator use.