Class A office building system design: Sustainability, energy efficiency
Class A office buildings are among the toughest projects an engineer can work on—complex structures, demanding clients, and advanced technology. Building owners want the most energy-efficient building possible.
Daniel G. Dowell, VP Energy Performance Contracting Sales, ABM, Raleigh-Durham, N.C.
Kurt Karnatz, PE, CEM, HBDP, HFDP, LEED AP, President, ESD, Chicago
Lance Kempf, PE, Director of Mechanical and Electrical Engineering, LEO A DALY, Minneapolis
Brian Michelson, PE, MEP Design Phase Manager, Mortenson Construction, Minneapolis
Joseph H. Talbert, PE, ARM, Project Manager, Aon Fire Protection Engineering, Lincolnshire, Ill.
CSE: Energy efficiency and sustainability are often a request from building owners. What net zero energy (NZE) and/or high-performance systems have you recently specified on a Class A office building (either an existing building or new construction)?
Daniel G. Dowell: Several systems are available to assist in this area. Solar will continue to grow in popularity as new incentives are created to reduce our dependence on coal as a fuel source. In addition, any system (controls, power monitoring, energy dashboards) that creates awareness on energy consumption by the building occupants tends to change behaviors in a positive manner. Power monitoring and energy dashboards are great investments as they tend to be less costly to implement.
Karnatz: In a recent NZE office building we designed, we used underfloor air distribution (UFAD) as the primary air-distribution method, ground-source heat rejection, a photovoltaic farm on the roof/surface decks to generate power, and solar concentrators for hot water. It is important to first explore and apply all possible passive strategies including situational, geometric, and shading opportunities. Another important component is educating the client on how to reduce operational loads.
CSE: Many aspects of sustainability (power, HVAC, maintenance, etc.) require building personnel to follow certain practices to be effective. What, if anything, can an engineer do to help increase chances of success in this area?
Karnatz: Because of all the technology that now comes with a building, the engineer must be able to guide the client and operating personnel on how to best run the building. Getting these stakeholders to the table as early in the design process as possible is the best way to begin on the path to successful operation.
Dowell: Numerous national organizations point to maintenance and constant commissioning as a very effective way of reducing operating expenses. As a national service provider and operator of billions of square footage of buildings, we have also found these services to be an effective way of meeting occupant-comfort requirements at the lowest energy-consumption rate. It ensures that service providers, technicians, and executives are all focused on keeping energy consumption to a minimum.
CSE: Please share a Class A office building success story in which you were able to enhance sustainability of an existing building.
Dowell: ABM's Energy Solutions division has not performed a sustainability program on a Class A office building. We have an extensive history with retail facilities, universities, K-12 schools, municipal government, and federal institutions. We have helped these clients save from 18% to as high as 60% of their utility expenses, with average savings being 28%.
Karnatz: One notable example is the Dirksen Building in Chicago. We completed an HVAC, automation, lighting, and plumbing-fixture retrofit over the entire building. In the end, we reduced total annual energy consumption by 34% and water by 41% over the average annual consumption for the 10 years prior to the retrofit.
CSE: Please describe your experience in smart or intelligent Class A office buildings.
Karnatz: One of the primary focuses of our business is intelligent buildings. We are excited by the maturation of building and peripheral technologies and the possibilities this presents to our clients when systems are properly stitched together. We believe engineers need to do a better job at educating clients in understanding what an intelligent building is, and avoid using words like "smart" and "green." Too often, we encounter clients that are disillusioned and believe that an intelligent building is a supercharged BAS that has some metering, lighting control, fault detection, and dashboard layered on it; whereas, in actuality, there are 15 or so core systems that together make up an intelligent building.
It is often not possible to establish a business case to integrate all of these systems together at once to achieve an ultimate end outcome when things continuously evolve. We work with our clients to establish a long-range vision and master plan that begins with an integrated and converged network that is open, scalable over time, and doesn't preclude the integration of future, yet-to-be-developed technologies. We believe that many current systems and providers who do not subscribe to this will be leapfrogged by the rapid developments in this area.
CSE: Have you worked with a Class A office building client to specify kiosks or other prominently displayed energy efficiency monitoring systems in a building? What types of tools are clients requesting to encourage their people to save energy?
Karnatz: On nearly all of our recent projects, we have implemented multiple-channel visualization and awareness systems. This includes lobby kiosks, elevator graphics, operator/occupant dashboards, and mobile communications. Providing real-time awareness and varying levels of control to the occupant creates a sense of empowerment and accountability that drives positive behavioral change. This results in greater experiential satisfaction and better economic outcomes.
Dowell: We have not been implementing these for any Class A space, but we have for schools and some retail space. They typically save 7% to 10% of baseline energy costs because they track occupant behaviors and how they affect consumption. We are contemplating using "energy" kiosks on all projects as a means of demonstrating the success of the program and to enhance our measurement and verification program.