Building Services/Vertical Transportation/Siting Lifts
The number and location of lifts should be very carefully considered when buildings are designed as it is usually very difficult and expensive to retrofit a lift shaft. Typically, lifts are installed wherever there are stairs and it is good practice to group such services together around a ‘core’, along with pipe and cable risers. In some cases, it is preferable to have several adjacent lifts rather than separate lifts in different places and there are advantages to putting lifts together in that they can share controls. In this case, when one of the call buttons is pressed, the system sends the nearest lift that is going in the right direction. This makes most effective use of the lifts, although goods lifts and passenger lifts should not share the same controls as goods operatives may press a button wanting a lift larger enough for a pallet and a small passenger lift will turn up or passengers will call a lift and find it full of goods so they cannot use it, neither of which situation gives the building occupants much faith in the lift design.
In high rise buildings with more than about 30 floors, ‘express’ lifts are often used. The ‘express’ lifts typically only call at the ground floor and ‘sky lobbies’ every thirty floors or so apart. Passengers wishing to alight at floors not served by the express lifts alight at their nearest sky lobby then take another lift from a separate bank of lifts that only serves those intermediate floors.