BUILDING SERVICE SYSTEMS
Harri Hakala, Marja-Liisa Siikonen, Tapio Tyni and Jari Ylinen
According to elevator traffic studies, the traffic patterns in an office building, such as number of starts, round trips, and number of transported passengers, are repeated quite the same from day to day. In this study, the energy consumption of elevators in tall office buildings is studied by measurements and traffic simulations. A method using elevator load and travel distributions in calculating energy consumption is introduced. The simulation results are verified by measurements in a single-tenant office building. The proportions of savings gained by different drive systems and machinery as well as control systems are compared. A case study for yearly energy consumption in a tall building is presented.
According to the GIBSE guide, elevators consume about 4-7% of the total energy load in an office building [GIBSE]. In Finland, measurements were made in low-rise office buildings with 4-6 floors. In these buildings, the electricity consumption was somewhat lower, about 1-3% of the total electricity load of the building. Most of the energy in prestige office buildings is consumed by the heating and hot water systems, lighting and office equipment, such as computers [Field]. The energy needed for space heating, ventilation, or air conditioning also depends on the outside temperature. Tall buildings vary in height and shape, and in their usage, as well as in elevator layout. In fact, there is no such thing as a typical high-rise building. Consequently, generalized statements about relative elevator energy consumption in tall buildings are difficult to formulate.
Owing to the uniqueness of tall buildings, this article concentrates on two specific office buildings, one in Finland and the other in Australia. The energy consumption of modern traction elevators and control systems is compared with technology that is about ten years old.