Mechanical floor
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A mechanical floor, mechanical penthouse, mechanical layer or mechanical level is a
concerns.While most buildings have mechanical rooms, typically in the basement, tall buildings require dedicated floors throughout the structure for this purpose, for a variety of reasons discussed below. Because they use up valuable floor area (just like elevator shafts), engineers try to minimize the number of mechanical floors while allowing for sufficient redundancy in the services they provide. As a rule of thumb, skyscrapers require a mechanical floor for every 10 tenant floors (10%), although this percentage can vary widely (see examples below). In some buildings, they are clustered in groups that divide the building into blocks, while in others they are spread evenly through the structure, and in still others, they are mostly concentrated at the top.
Mechanical floors are generally counted in the building's
Structural concerns
Some skyscrapers have narrow building cores that require stabilization to prevent collapse. Typically, this is accomplished by joining the core to the external supercolumns at regular intervals using
This layout is usually reflected in the internal
Elevators that reach the top tenant floor also require overhead machine rooms; those are sometimes put into full-size mechanical floors but most often into a mechanical penthouse, which can also contain communications gear and window-washing equipment. On most building designs, this is a simple "box" on the roof, while on others it is concealed inside a decorative spire. A consequence of this is that if the topmost mechanical floors are counted in the total, there can be no such thing as a true "top-floor office" in a skyscraper with this design.
Mechanical concerns
Besides structural support and elevator management, the primary purpose of mechanical floors is services such as
In particular, the problem of bringing and keeping water on the upper floors is an important constraint in the design of skyscrapers. Water is necessary for tenant use,
Special care is taken towards fire safety on mechanical floors that contain generators, compressors, and elevator machine rooms, since oil is used as either a fuel or lubricant in those elements.
Mechanical floors also contain communication and control systems that service the building and sometimes outbound communications, such as through a large rooftop
Modern computerized HVAC control systems minimize the problem of equipment distribution among floors by enabling central remote control.
Aesthetics concerns
Most mechanical floors require external vents or
In the
Conversely, designers of the recent
Some low-rise, residential (usually apartment buildings or dormitories), or non-residential buildings, especially built in a architecture style that promotes the use of elements such as sloped roofs and/or bell towers, may have mechanical floors disguised as attics or towers. In this case, the ventilation systems of the mechanical floor are seen as gable vents, dormers, or abat-sons (louvers in a bell tower). Examples include some buildings in UCLA, like Dodd Hall, which has a mechanical floor disguised as an attic and a bell tower.
Examples
These are examples of above-ground mechanical floor layouts for some of the world's tallest buildings. In each case, mechanical penthouses and spires are counted as floors, leading to higher total floor counts than usual.
- Taipei 101: Floors 7–8, 17–18, 25–26, 34, 42, 50, 58, 66, 74, 82, 87, 90, 92 to 100 in the penthouse – total 17/102, 17%. The official count of 11[3] corresponds to the number of groups in the office section. Floors 92–100 contain communications equipment[4] and so are not typically counted as mechanical since they do not service the building itself.
- One World Trade Center: Floors 2–19, 92–99, and 103–104 – total 28/104, 26%).
- skylobbies which in many buildings sit directly on top of the mechanical floors. However, the twin towers had one occupied office floor under each skylobby, accessible through escalators.
- Sears Tower): Levels 29–32, 64–65, 88–89, 104–108, 109 (penthouse), and 110 (penthouse roof) – total 15/110, 13%.
- Petronas Towers: Floors 6–7, 38–40, 43, 84, 87–88 – total 9/88, 10%[5]
- Jin Mao Building: Floors 51–52, and 89–93 in the penthouse – total 7/93, 7.5%[6]
- Burj Khalifa: Floors 17–18, 40–42, 73–75, 109–111, 136–138, 155, and 160–168, in the penthouse – total 25/168, 15%
- John Hancock Center: Floors 16–17, 42–43, 93, 99–100 (penthouse) – total 7/100, 7%
- Empire State Building: Floors 87–101 – total 15/102, 14%
- International Commerce Center: Floors 6–7, 17–18, 24–25, 34, 43, 52, 61, 70, 79, 88, 97, 104, and 114 – total 17/108, 14%
- Shanghai World Financial Center: Floors 6, 18, 30, 42, 54, 66, 78, 89, and 90 – total 9/101, 9%
- Lotte World Tower: Floors 3–4, 13, 21–23, 39–41, 59, 60, 72–75, 83, 84, 102–106, 115, and 116 – total 24/123, 20%
References
- ^ "in-arch.net". Archived from the original on 2017-05-10. Retrieved 2016-02-06.
- ^ "Mechanical Room Definition". Law Insider.
- ^ "Design Architecture". Archived from the original on 2005-03-08.
- ^ "TAIPEI101 Tower". Archived from the original on 2005-02-13.
- ^ New York Times, Elevator World magazine
- ^ SkyscraperPage
External links
- Case study for Hong Kong's Hong Kong University, Energy Features section