PSC Masterclass Series: The Ups and Downs of Lifts
While lifts are commonplace in modern multi-storey architecture, it is often considered a necessity alongside other services, as opposed to a key design opportunity. Lifts are an efficient way to move vertically as well as providing equitable access. In this masterclass, Senior Architect Vicky Vu explores the different options with lift mechanics, components, and design constraints.
How does it Work?
The essential principle of a lift (or elevator) is similar to a pulley system; operating with sophisticated, load bearing mechanisms. While there are many forms of lift mechanics, including the pneumatic elevator, capsule lift, freight elevator and smaller residential lifts, the most common are the traction and the hydraulic lift.
Traction vs Hydraulic
The traction (or cable) lift consists of steel cables and hoisting ropes that run above a pulley. These hoisting ropes are connected to the elevator car on one side, with the opposing side connected to a counterweight which travels on guide rails. The counterweight is generally equivalent to the car’s weight plus half of the maximum passenger weight. This provides load management and reduces the amount of energy required of the motor powering the mechanism. The counterweight system results in a smoother, more energy efficient lift, however these additional mechanisms require more space than the hydraulic lift.
The hydraulic lift is only suitable for low rise buildings (up to six storeys), however is often a cost efficient lift to install. This lift is driven by a piston that moves within a cylinder. This movement is achieved by pumping hydraulic oil to the cylinder causing the piston to lift the car easily and is controlled by an electrical valve. Hydraulic lifts have fewer moving parts resulting in cost efficient installation, however they are a slower and bumpier ride than that of a traction lift.
What does an Architect need to consider?
When designing for a multi-storey building, the inclusion of a lift is often inevitable, however there are many aspects that need to be considered early on in the design process. Lift shafts are typically the service core of the building, whether that be in the centre of the building or on an external shaft, and are a major coordination component of the design. This also means the aesthetics of not only the doors and internal car need to be considered, but the wayfinding and navigation associated with the lift, the grouping of lifts and the external shaft design also factor into the design.
To assist with the selection and placement of lifts, the following questions should be answered:
- How often does the lift need to operate?
- How many people will use the lift each day
- How far does the lift need to travel?
- Are any service lifts required?
How do we ensure safety?
Lifts have internally built safety mechanisms which result in infrequent faults. As designers, the most effective way to ensure user safety once a lift has been specified and installed is to confirm compliance with the relevant standards. AS 1735.2-1997 Lifts, Escalators and Moving Walks covers all aspects of lift installation, including operation, machine rooms, overhead equipment, clearances, landing doors and access, rated car capacity and construction, safety gear and more.
For any further information, refer to the Australian Standards or contact us.
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