L9: Elevator Systems Flashcards
(28 cards)
What happened to top floors when elevators were introduced?
Went from least valuable space to most valuable
How much of a building’s initial cost is the elevators?
10%
How much of a building’s energy use is elevators?
10%
Where are elevators commonly located and why?
In the core;
Least valuable space
Utilitarian space that all tenants can access
Core reinforced shear wall which provides bracing
What is the alternative to elevators being located in the core?
Along East/West sides;
Blocks harsh sun (glare/heat gain) but not suitable for multi-tenanted buildings
How do sky lobbies work?
Express elevators takes occupants to sky lobbies covering a range of floors where another set of elevators continues to exact destination
What are the two main purposes of sky lobbies?
Reducing wait time
Increasing leasable area (otherwise lower floors would just be elevator shafts)
What is the elevator equipment?
Machine room (machine, controller, hoist ropes) Moving components (car, counterweight, hoist ropes_ Stationary components (guide rails (car and counterweight), hydraulic car buffer, elevator shaft)
How heavy is the counterweight in an elevator system?
The weight of the car plus half the maximum load
What are hoist ropes and how are they used in elevator systems?
High tension steel cables with resin core
Used in sets of 4-8 per car to provide traction
What is a hydraulic car buffer?
Located at bottom of elevator shaft and slows car if breaks fail
What are the types of roping and sheave arrangement that can be used with a penthouse machine room?
1: 1 roping single wrap
1: 1 roping double wrap
2: 1 roping double wrap
What is 1:1 roping single wrap?
Rope connected to car and counterweight goes over traction and secondary sheaves
What is 1:1 roping double wrap?
Rope connected to car and counterweight goes over traction and secondary sheaves twice
What is 2:1 roping double wrap?
Rope comes from machine room, attaches to car and countweight with a pulley, and wraps around traction and secondary sheaves twice; lower power/cost but slower
What is the roping and sheave arrangement used with a basement machine room?
1:1 roping
What is 1:1 roping?
Rope connected to car, goes over idler sheave above, goes down to traction sheave in basement, goes back up to another idler sheave above, connects to counterweight; requires longer ropes
What are hydraulic elevators?
Hydraulic oil and pump drives pistons which lifts car; less expensive but very sloe and only for up to 6 storeys
What are the 4 types of elevator operations control?
Single automatic push button
Selective collective operation
Computerised system control
Destination control system
How do single automatic push-button elevators work?
Handles one call at a time; single button indicates if elevator is in use
How do selective collective operation elevators work?
Most standard; system stores calls until answered and elevator completes up/down runs stopping where necessary (most appropriate car sent )
How can wait times be improved with selective collective operation elevators?
Operating modes which send elevators to lobby at up peak times and to top floor at down peak times
How do computerised system control elevators work?
Using specialised software and algorithms designed to minimise waiting and trip time by considering factors like car load and distance and assigning priority status to expired calls (uses AI)
How do destination control system elevators work?
Floor is entered in control panels which indicate which elevator to take; avoids large random groups by grouping destinations efficiently
