The challenge: Tall and super-tall buildings: Energy efficiency
High-rise buildings aren’t just big—for engineers, they present big challenges. High-performance and sustainable buildings must meet certain energy efficiency requirements.
Jason Heffelmire, PE Gulf Coast operations director, TLC Engineering for Architecture, Tampa, Fla.
Mehdi Jalayerian, Executive vice president, Environmental Systems Design, Chicago, Ill.
Jim Quiter, PE, FSFPE, LEED AP, Principal, Arup, San Francisco, Calif.
CSE: Many aspects of sustainability (power, HVAC, maintenance, etc.) require building personnel to follow certain practices in order to be effective. What, if anything, can you as an engineer do to help increase chances of success in this area?
Jalayerian: Standardization of systems and their equipment components—or in other words, uniformity—not only facilitates a lean construction process through a repetitive design and installation but also reduces the risk of creating future troubleshooting complexity for the building engineers. This strategy is a critical part of the development of Kingdom Tower. In order to manage the expense of the design and facilitate a similar approach, standardization is being applied to components such as air handling units, head exchangers, pumps, storage tanks, electrical switchboards, transformers, systems risers, etc.
Heffelmire: We invite building personnel and system operators to our training sessions specifically designed for each project. We believe without proper maintenance, sustainability suffers. We also include the practices to follow on the plans and again in the specifications.
Quiter: Green buildings and fire safety create an interesting dilemma. What can be more sustainable than a building that doesn’t burn down? But sustainability can create issues that were not considered. Will increased insulation on a roof (or a green roof) impact the fire resistance by holding the heat in? Will a double façade create a chimney? Will insulation on the exterior wall create an avenue for external fire spread? How will natural ventilation impact smoke movement, particularly on a windy day? There are unintended impacts from building green that can be dealt with if they are thought about.
CSE: Could you please share a success story in which you were able to deliver a highly sustainable project to a tall/super-high-rise client? Statistics on energy savings and other supporting evidence would be helpful.
Heffelmire: Our more than 245 LEED certified projects, many of which achieved LEED Platinum status, were not high-rises. Energy savings on our last LEED Platinum project were not as predicted due to different owner operating schedules. Our high-rise building systems were basically the same systems we use in our LEED projects, but decoupled because of the pressure problems.
CSE: Could you please describe any experience you have using sustainable heating/cooling technologies, such as geothermal systems or ground source heat pumps?
Heffelmire: In Florida, ground source heat pumps and geothermal systems are very popular because of our low water table, but are more expensive at this time. We have done some successful small projects using these systems.
CSE: Please describe your experience with high-performance building projects.
Jalayerian: The Federation of Korean Industries tower is the first office tower in South Korea to use a pressurized underfloor air distribution system, as well as the first commercial building to receive the highest score for sustainable design—Grade 1 in Environmental Friendly Building Rating—in an independent review conducted by the Korea Institute of Construction Technology (KICT). The underfloor air distribution system allows for greater individual temperature control and full flexibility for the office space, and the building’s central cooling and heating plant uses highly efficient systems components and reduces the electrical demand through its ice storage system.