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Elevators are mechanical platforms designed to transport people and goods between two or more floor levels vertically within a dedicated shaft that connects the different floors of a building. They are an important part of both residential and commercial buildings.
The load-carrying unit, including the supporting platform, and the guided frame, is termed a guided car. Elevators or lifts are commonly used in buildings having more than four stories.Â
This article discusses the various types of elevators used in buildings and their features.
Types of Elevators Used in Buildings
Elevators can be classified into various types based on their use and working mechanism.
Based on the Function
- Passenger elevators: These are lifts provided in flats, residences, hotels, etc., for the transportation of passengers.
- Service elevators: These are lifts used to carry goods along with people.
- Goods elevators: These elevators are primarily used to transport goods, along with lift attendants, and persons for helping with the loading and unloading of the goods.
Based on the working mechanism
1. Traction Elevators
Traction elevators are lifted using ropes that pass over a wheel connected to an electric motor. When the electric motor starts, the wheel is set in motion. This pulls the rope and lifts the elevator car to the required floor levels.
The wheel for this arrangement is usually placed in the machine room for the building on the highest floor. A counterweight is added to make the elevators more efficient by offsetting the weight of the car and the occupants. This way, the speed of the wheel and the rope coordination is achieved. Traction elevators are used for floor levels up to 2000 feet.
Traction elevators are of two types:
- Geared Traction Elevator: In this type, the wheel is driven by having a gearbox attached to the motor. These elevators achieve a travel speed of up to 500 feet per minute. The maximum travel distance offered by geared traction lifts is 250 feet.
- Gearless Traction Elevator: In this type, the wheel is directly attached to the motor. It offers a speed of up to 2000 feet per minute and has a maximum travel distance of around 2000 feet. It is the top choice for high-rise buildings.
2. Hydraulic Elevators
Hydraulic elevators employ a piston at the bottom of the elevator to push it to different levels. An electric motor forces oil or any hydraulic fluid to move the piston. This type of lift has a slower mechanism compared to traction elevators.
Hydraulic elevators are used for low-rise applications (2-8 stories). It can travel at a maximum speed of 200 feet per minute.
Hydraulic elevators can be:
- Conventional hydraulic elevators: They have a sheave that extends below the floor of the elevator pit. As the elevator descends, the pit supports the retracting piston. The approximate distance it can travel is 60 feet.
- Hole-less hydraulic elevators: These types of elevators are similar to conventional hydraulic elevators, except they do not require a sheave or hole below the pit. The telescopic piston arrangement allows up to 50 feet of travel distance, while the non-telescopic piston allows about 20 feet.
- Roped hydraulic elevators: These elevators use both ropes and pistons to move the elevator car. The maximum distance it can travel is 60 feet.
3. Machine-Room-Less (MRL) Elevators
MRL elevators can be traction or hydraulic elevators that do not require a dedicated machine room above the elevated shaft. Here, the machine sits in the override space. For any maintenance and repairs, the unit is accessed from the top of the elevator cab.
5. Vacuum (Air-Driven) Home Elevators
Vacuum elevators do not use any cables or pulley systems to operate. Instead, this elevator is a tube in a sealed vacuum arrangement operated by controlling air pressure. These are mostly used for residential applications for single to three passenger models (wheelchair accessible models).
FAQs
The types of elevators based on function are:
1. Passenger elevator
2. Goods elevator
3. Service elevator
The types of elevators based on the working mechanism are:
1. Traction elevators
2. Hydraulic elevators
3. Machine-room-less (MRL) elevators
4. Vacuum home elevators
Vacuum elevators do not use any cables or pulley systems to operate. Instead, this elevator is a tube in a sealed vacuum arrangement operated by controlling air pressure. These are mostly used for residential applications for single to three passenger models (wheelchair accessible models).
Hydraulic elevators can be:
1. Conventional hydraulic elevators
2. Hole-less hydraulic elevators
3. Roped hydraulic elevators
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