servicing large buildings
DESCRIPTION
TRANSCRIPT
Services for large buildings
Increase in size requires new solutions
Big buildings need big ideas
• Holes in the wall can ventilate small buildings
• Holes in the walls can’t ventilate deep buildings
• Ducted mechanical ventilation needed
Ventilating deep buildings
• Mechanical air handling needed to reach the interior
• Large ducting needed to move air around in large volumes at low speed
• Increased building volume needed to accommodate the large ducting
• Servicing costs both directly (air handling systems) and indirectly (increased building size to house mechanical plant) raise the basic costs of large buildings.
Water supply in tall buildings
pump
Pressure release valves now needed
Water to short buildings delivered by gravity, no problems
Water to tall buildings
• Just scaling up a small system doesn’t work
• Pumping needed• Only stored water can be used, so
health problems• Pressure in pipe work can be immense
at lowest levels• Then you need hot water too…
Heating tall buildings
Boiler plant
Pressure enormous at base, water too hot
Pressure low at top, water too cold
High temperature fluids transport heat more efficiently.
Circulating, very high temp steam
Boiler plant- generating high temp, high pressure steam
Heat exchangers on each floor (calorifiers) Use steam to heat low pressure water locally
Protecting enclosure needed, steam is dangerous
Heating tall buildings
• Again, scaling up small plant doesn’t work
• High temperature steam needed• Local calorifiers and heating controls
needed, probably on each floor• Safety is endangered, so protected
enclosures and warning systems needed
• Heating tall buildings is expensive.
Air-conditioning tall buildings
Individual, local a/c units can be used. This is madness, messy, environmentally disastrous, noisy and uses up all the available wall space.
Centralised a/c
Cooling plant, usually on top floor, vents heat, creates and circulates very cold water
Local air intake, air cooled by cold water
OR
Ducted conditioned air from air conditioning plants every 10 floors or so
And there’s more
• What about electricity?– 240V AC will not provide enough power for
a large building, it’s only enough for a single house.
– 3 phase power supply is needed, which is far more dangerous
– Protective enclosures needed for the high tension supplies, which are tapped for a 240 V supply at each floor
Electricity supply for tall buildings
High tension bare copper conductors, “Bus bars” run up a protected service shaft. Provide “3 phase” supply
Each floor taps off a single phase, 240V supply from one live bus bar and the neutral bar
Where’s the floor space gone?
• Services for multi-storied buildings devour floor space.
• We haven’t even put the lifts and stairs in yet
Hang the services on the outside?
• Pompidou Centre, Paris• HSBC HQ, Hong Kong
Stick them on top?
• “Chippendale Building” New York
• Seagram building, New York
Plan view
Service tower
Office floor
What about lifts?
• Multi-storey buildings have lots and lots of people in them
• One lift for 1,000 people on 100 floors is not going to work very well…
Double Decker lifts
• Simple solution which halves the problem
• Each floor of the lift serves alternate floors in the building
• Escalator needed to the second lowest level
• Problems arise with disabled access.
• Building must have an even number of floors and all floor heights identical…
Multiple lifts
• Several lift shafts will help, but they take up an enormous amount of floor space
• The ground floor of a modern skyscrapers may have 25-33% of its ground floor area devoted to lifts and lobbies.
Multi-level lift grouping
Sky lobby
Sky lobby
Ground lobby
High speed lifts just between lobbies
Zoned lifts served by lobbies
In some large buildings there may be several lifts in a lift shaft, one above the other.
Sky lobby, Central Plaza building Hong Kong
• Sky lobbies often used for café’s gardens, a/c equipment, anything to make people forget that they are having to change lifts, whether they want to or not
Burj Dubai: tallest building in the world
Summary
• Servicing tall and large buildings is highly complex, inevitably expensive and in some cases dangerous.
• Qualified services/mechanical engineer needs to be part of the design team
• Do not scale up small service installations to meet the needs of large buildings, it doesn’t work
• Article about use of a sky lobby in Austriahttp://www.architectureweek.com/2002/0130/environment_1-1.html