Office building electrical, power system design has changed
COVID, employee well-being and indoor air quality issues have all changed the way office building electrical and power systems are considered
- Daniel Donahoe, PE, Senior Mechanical Engineer, LEO A DALY, Omaha, NE
- Tyler Jensen, PE, LEED AP, Studio Leader, ESD, Chicago, IL
- Brad McNiff, PE, LEED AP, WELL AP, Principal, GHT Limited, Arlington, VA
- Gerald Williams, PE, LEED AP, Senior Mechanical Engineer, CRB, St. Louis, MO
What are some key differences in electrical, lighting and power systems you might incorporate in an office building, compared to other projects?
Daniel Donahoe: Office spaces have unique lighting challenges, especially those with open-plan environments. Office spaces tend to be high-performance, high-dollar spaces with expensive conference rooms or board rooms. They typically demand a higher quality lighting system with sophisticated lighting controls and AV integration. More and more, they are smart conference rooms that can be checked out digitally and show availability digitally. They have controls built in that allow occupants to interact with TV screens, control the sound from the furniture and control the lights and temperature from a touch screen.
How does your team work with the architect, owner and other project team members so the electrical/power systems are flexible and sustainable?
Daniel Donahoe: Flexibility is critical in today’s workplace, especially as hoteling and hybrid scheduling enter the mainstream. This means the furniture needs to be smart, connected and powered, which adds complexity to the electrical engineer’s job. One key question we always have to ask is, how does power get to workstations? Floor boxes are helpful in maximizing versatility, allowing the furniture layout to change over time. Central battery inverters for egress lighting reduces the quantity of individual batteries required for a project. This reduction in the quantity of batteries needed is a more sustainable solution.
Tyler Jensen: For core and shell office buildings, flexibility is critical for electrical distribution systems. Building owners want to be able to accommodate high power user tenants such as trading firms, but don’t want to overbuild infrastructure. Bus duct riser systems allow power capacity to be allocated efficiently to specific floors or tenants. For high-rise office buildings in Chicago, we have also run high-voltage utility feeders through the building with stacked utility vaults on all floors. Most floors include a utility transformer but some are empty so we can easily add capacity where specific tenants need higher power density.
Sophisticated lighting controls, holistic lighting and other techniques are often incorporated into design. What unique lighting systems are you working on in office buildings?
Daniel Donahoe: We’re seeing more demand for lighting with acoustical elements integrated. This helps create a more comfortable work environment, especially in open offices where there are more hard surfaces. These can get loud without some acoustic remediation. Integrating the acoustical treatment with lighting is a stylish way to treat the sound of the room, softening reverberations while creating visual interest. We’re seeing a lot of light fixtures that are woven together with sculptural baffles. These look great aesthetically, appearing as an extension of the lighting system.
What types of unusual standby, emergency or backup power systems have you specified for such facilities? What were the project goals?
Daniel Donahoe: We’re seeing owners beginning to move away from diesel and embrace the benefits of natural gas generation.
What are some of the challenges when designing electrical, power and lighting for office building projects?
Daniel Donahoe: Where does the power come from in open office environments? In a hybrid office, the furniture systems absolutely must be integrated with power and data. In an open office environment, if you want to maximize use and flexibility in areas that are not along a wall, it requires specialized floor boxes. These provide all the power and data connection you need.
What kind of lighting designs have you incorporated into such a project, either for energy efficiency or to increase the occupant’s experience?
Daniel Donahoe: LEDs are totally commonplace now and necessary when designing to more recent code iterations. They are now available in a variety of different form factors and have become very reliable.