Introduction  

An elevator   (or lift in the Commonwealth excluding Canada) is a type of vertical transport equipment that efficiently moves people or goods between floors (levels, decks) of a building, vessel or other structures. Elevators are generally powered by electric motors that either drive traction cables or counterweight systems like a hoist, or pump hydraulic fluid to raise a cylindrical piston like a jack. 

There are three types of convoying methods in buildings, Elevators & Escalators & Ramps, and they have different dimensions and uses according to building type & number of users in it. 

Elevator Types1. According to hoist mechanism.

2. According to building height.

3. According to building type.

4. According to elevator Location.

5. According to Special uses.

1- According to hoist mechanism:

Elevators will be classified according to hoist mechanism to 4 main types as follows:1. Hydraulic Elevators 

2. Traction Elevators 

3. Climbing elevator 

4. Pneumatic Elevators 

1- Hydraulic Elevators (Push Elevators)

Hydraulic Elevators

Hydraulic elevators are supported by a piston at the bottom of the elevator that pushes the elevator up. They are used for low-rise applications of 2-8 stories and travel at a maximum speed of 200 feet per minute. The machine room for hydraulic elevators is located at the lowest level adjacent to the elevator shaft. Hydraulic elevators have many two main types as follows: 

A- Holed (Conventional) Hydraulic Elevators 

Holed (Conventional) Hydraulic Elevators

They have a sheave that extends below the floor of the elevator pit, which accepts the retracting piston as the elevator descends. Some configurations have a telescoping piston that collapses and requires a shallower hole below the pit. Max travel distance is approximately 60 feet. 

B- Hole-less Hydraulic Elevators 

They have a piston on either side of the cab. It can be divided to 3 different types as follows: 

a- Telescopic Hydraulic Elevators:

Telescopic Hydraulic Elevators

In this configuration, the telescoping pistons are fixed at the base of the pit and do not require a sheave or hole below the pit and has 2 or 3 pieces of telescoping pistons. Telescoping pistons allow up to 50 feet of travel distance. 

b- Non-telescoping (single stage) Hydraulic Elevators: 

Non-telescoping (single stage) Hydraulic Elevators

it has one piston and only allows about 20 feet of travel distance. 

c- Roped Hydraulic Elevators 

Roped Hydraulic Elevators

They use a combination of ropes and a piston to move the elevator. Maximum travel distance is about 60 feet. 

2- Traction Elevators (Pull Elevators)  

Traction Elevators (Pull Elevators)

Traction elevators are lifted by ropes, which pass over a wheel attached to an electric motor above the elevator shaft. They are used for mid and high-rise applications and have much higher travel speeds than hydraulic elevators. A counter weight makes the elevators more efficient. Traction elevators have 3 main types as follows: 

A- Geared Traction Elevators: 

Geared Traction Elevators

they have a gearbox that is attached to the motor, which drives the wheel that moves the ropes. Geared traction elevators are capable of travel speeds up to 500 feet per minute. 

B- Gear-less Traction Elevators:

Gear-less Traction Elevators

they have the wheel attached directly to the motor. Gear-less traction elevators are capable of speeds up to 2000 feet per minute. 

C- Machine-Room-Less Elevators:

Machine-Room-Less Elevators

they are typically traction elevators that do not have a dedicated machine room above the elevator shaft. The machine sits in the override space and the controls sit above the ceiling adjacent to the elevator shaft. Machine-room-less elevators are becoming more common; however, many maintenance departments do not like them due to the hassle of working on a ladder as opposed to within a room. 

3- Climbing elevator

Climbing elevator

They hold their own power device on them, mostly electric or combustion engine. Climbing elevators are often used in work and construction areas.

4- Pneumatic Elevators  

Pneumatic Elevators

Pneumatic elevators are raised and lowered by controlling air pressure in a chamber in which the elevator sits. By simple principles of physics; the difference in air pressure above and beneath the vacuum elevator cab literally transports cab by air. It is the vacuum pumps or turbines that pull cab up to the next Floor and the slow release of air pressure that floats cab down. They are especially ideal for existing homes due to their compact design because excavating a pit and hoist way are not required. 

2- According to building height  

A- Low-Rise buildings (1- 3 stories) Buildings up to about (1 to 3) stories typically use hydraulic elevators because of their lower initial cost 

B- Mid-Rise buildings (4 -11 stories) Buildings up to about (4 to 11) stories typically use Geared Traction Elevators 

C- High-Rise buildings (12 + stories) 

Buildings up to about 12+ stories typically use Gear-Less Traction Elevators 

3- According to building type

Elevators will be classified according to building type to 6 main types as follows: 1. Hospital Elevators.

2. Residential /Domestic Elevators.

3. Agricultural Elevators.

4. Industrial Elevators.

5. Commercial Elevators.

6. Parking buildings Elevators.

1- Hospital Elevators  

Hospital Elevators

A- Hospital Bed Elevators Hospital bed elevators generally transport patients who are not well enough to sit up even in a wheelchair. One of the features of bed elevators should be its ability to transport the patient has smoothly as possible with minimal amount of bumping and jostling. Many contemporary bed elevators are manufactured to consume extremely low amounts of power and to be durable with a number of safety features built-in. Hospital bed elevators generally draw very little power so that should there be a power outage they are still operational off the hospital's backup power supply. Most often there will be a rear and a front entry to the elevator cabin. 

B- Hospital Stretcher Lift They usually are smaller than bed elevators. This particular type of elevator is usually hydraulic or traction based depending on the location of the machine room. They are specifically manufactured to be low-noise bed elevators that smoothly transport patients, doctors, nurses and hospital staff between floors, allowing them the utmost in comfort. Because hospital bed elevators are only used for transporting patients and hospital staff they arrived at their location quite quickly, eliminating lengthy waits. Many of these bed elevators are key operated so as to

prohibit use by the general public. 

2- Residential /Domestic Elevators   They are usually just on a much smaller scale than industrial or commercial elevators. 

A- Passenger Elevators 

Passenger Elevators

Domestic elevators which are intended to move passengers up and down stairs in a multilevel residence are quite similar to those used in large public buildings. They can be built either inside the home or outside the home and can be pneumatic vacuum, electric, hydraulic or cable elevators. Most often domestic elevators designed for carrying passengers in a residential setting only carry perhaps two to four people safely and comfortably. 

B- Stairway Elevators 

Stairway Elevators

Stairway elevators are generally installed in homes where someone in the family has problems with mobility. This type of domestic elevators simply runs on a rail up and down and existing staircase. They can run either in a straight line or around a curved stairway. Stairway elevators can be constructed both inside and outside the home.

b.1 - Vertical Wheelchair Elevators 

Vertical Wheelchair Elevators

Interior vertical wheelchair elevators can easily be installed when space is limited. They can be constructed in such a way as to allow both front and rear entry and the platform is generally 4.5 feet by 5 feet, unless a custom size is called for. Vertical elevators are called for when the staircase winds around several levels. 

b.2 - Wheelchair Elevators on an Incline 

Wheelchair Elevators on an Incline

Wheelchair elevators on an incline are generally installed when the staircase simply goes up one level or perhaps two. If there are several winds in the staircase, wheelchair elevators on an incline would not be well suited. Most often this type of elevator is called for when there is not adequate space to facilitate a more spacious vertical wheelchair elevator. 

C- Dumbwaiters Elevators 

Dumbwaiters Elevators

They are small freight elevators intended to carry objects rather than people , Whenever groceries or laundry need to be sent up and down the stairs without making unnecessary trips that can quickly tire people , people can simply place what needs to be transported in the dumbwaiter and press the button to send it up or down stairs. Dumbwaiters are most often built into or adjacent to a wall. 

A simple dumbwaiter is a movable frame in a shaft, dropped by a rope on a pulley, guided by rails; most dumbwaiters have a shaft, car, and capacity smaller than those of passenger elevators, usually 100 to 1000 lbs 

3- Agricultural applications:

A- Bucket Elevators Bucket elevator used to move crops which have been newly harvested up and into silo. Bucket elevators are manufactured in such a way that they can move heavy loads quite easily. They can be belt driven or chain driven and they can move vertically, horizontally or at an incline. 

A.1- Centrifugal discharge elevators 

Centrifugal discharge elevators

Bucket elevators are sometimes referred to as conveyor buckets, most often when the movement is horizontal or on an incline. However, technically speaking, vertical

movement is also accomplished with a conveyor belt or chain. The centrifugal discharge bucket elevator is perhaps the most common type. Of course, as the name implies the elevator is driven by centrifugal force. This type of elevator has lower speeds and the buckets are often placed relatively closely together. 

A.2 Vertical bucket Elevators 

Vertical bucket Elevators

Vertical bucket elevators usually have buckets that are well spaced with bottoms that are rounded, and are often referred to as grain legs. Part of the reason for this is balance which keeps the contents in the buckets as they move up the elevator so that spillage isn't a problem. Vertical bucket elevators need to be used at a much slower pace both to avoid spilling contents and also because much of the time they carry loads that are quite heavy. 

4- Industrial Elevators  

The most common types of industrial elevators are hoist elevators and incline elevators. These types of elevators are built to carry huge amounts of weight effortlessly, therefore the term industrial elevators. This type of elevators is used in construction, warehouses, and shipyards. 

A-Hoist Elevators 

Hoist Elevators

Hoist elevators are operated by a pulley or series of pulleys and they can be a simple platform or a cage in which humans or heavy materials are moved up and down during industrial applications. Generally, a pulley operates a rope or chain that wraps around a drum causing the elevator to rise or descend. It is said that hoist elevators are powered by either electricity or air, but even that isn't quite true because electricity is needed to pump air. Hoist elevators carrying materials and equipment to upper levels as needed while the building is being constructed. They are also commonly used to load equipment and supplies on large seagoing vessels. 

B- Incline Elevators 

Incline Elevators

The equipment and supplies are placed on a form of conveyor belt that continues turning bringing the cargo up to its destination where it is quickly unloaded as the belt continues turning around. This is a much quicker method of loading and unloading cargo than with a hoist elevator because there is no stopping to unload. Everything happens in one fluid motion. Incline elevators when used for industrial purposes are usually temporary and mobile. Many are on wheels and can be easily moved from one dock or location to the next. 

5- Parking Elevators

A- Parking Elevators for Passengers  

Parking Elevators for Passengers

Most parking garages have parking elevators for passengers that allow them the convenience of going up or down several levels without the necessity of climbing stairs. Sometimes these elevators have front and rear entry and can be built with a number of optional features such as key access to certain floors. Most underground garages have parking elevators for passengers. 

B- Conventional Parking Elevators  

Conventional Parking Elevators

The conventional parking elevators are built to move vehicles to upper or lower levels of the building because of their space saving feature. With ramps on and off parking levels consume a lot of space which could be better utilized as parking spaces for vehicles. With the addition of parking elevators, vehicles can be transported up and down as many levels as necessary by taking up only the space required for that vehicle. But maintain the need for attendants to sit in the car, in the elevator and park it on the floor on which there is space. 

C- Auto Car Parking Elevators  

Auto Car Parking Elevators

As against cars being driven (on ramps) or carried (in car lifts) to different levels in conventional multi-level parking, cars are driven at only one level for parking or retrieval, Cars are parked in steel pallets and a target pallet comes up or down to the driveway level at the press of a button, for parking or retrieval. 

Such car parking systems or auto parking systems are also referred to by various other names in different parts of the world, such as “auto-parking”, "stack-parking", "mechanized parking", "mechanical parking", "parkomat", “modular parking” etc. 

This type can be divided to many different types as follows: 

Auto Car Parking Elevators Types

C.1 Square Type The system arranges many carriers on several intended floors and a lift installed either at both ends or at the center goes up and down with vehicles loaded. It is designed so that vehicles can be parked and retrieved by moving a pallet horizontally. It is safer than other systems and the cutting -edge mechanical car parking system, and operates very smoothly. It is fit for installation in a narrow and long shaped lot or an underground of a building. 

C.2 Level Type The system is designed so that car parking lots move both horizontally and circulary to park vehicles. Many carriers are arrayed in more than one row in the car parking lot and the system works by moving both horizontally and circulary the carriers at both ends of level. 

C.3 Rotary Type A system that two sprockets as a set are fixed; one onto a upper part of a structure and the other onto a lower part and then a cage hung to a attachment of a special chain circulates with vehicles loaded. This system with simple operation and low

installation cost requires a small lot for installing equipments and may be divided to subsystems as follows: 

1. Bottom entering type: A type that cars are parted and retrieved at the bottom of parking equiments.2. Middle entering type: A type that cars are parked and retrieved at the middle of parking equiments.3. Top entering type: This type that cars are parked and retrieved at the top of parking equiments. 

C.4 story Type

A system is featured by using all parking lots on the first floor as the place for car parking/retrieval. Carriers are arranged on two levels, where cars are parked through both vertical and horizontal movements. With short construction period and easy installation, it is fit household use or a small scale parking lot. 

C.5 Puzzle Type

The carriers are arranged on 3-storey and more than 3-story, a specific carrier moves both vertically and horizontally to and from more than one car entrance on the same level, It is an economical system, has safe structures, and designed to utilize space efficiently to install parking equipments. As there are few laws and regulations on this system and the installation period is short. it is fit for utilizing an idle lot in residential areas. 

C.6 Turn Table

A turntable is equipment which changes directions itself utilize efficiently a limited space. The turntable installed in front of parking equipments provides drivers with convenience and safety. 

C.7 Elevator Type

This System is arranged On multi-levels and designed to automatically Carry and park Cars by a lift and a Carrier installed inside parking lots A pallet for parking is built in independently on each level, that is Carried by a Cage from parking lots to the lift that moves Vertically to an entrance/exit. This System one of the most Up-to-date mechanical Car parking System, is featured With Speedy parking/retrieval, widely installed In a City area, and fit for a large Scale Car parking equipment that

can maximize Utilization of a limited parking Space. 

C.8 Lift Traverser Type

This is a full automatically mechanical car parking system that minimizes the time for parking/retrieval by the simultaneous movements, both horizontally and vertically, of a car lift. As the utilization of both parking space and floor space can be maximized and easy forward parking/ retrieval of vehicles is possible from any moving lane, and the convenience of user can be maximized. The noise level is low and the durability of car bay is semi-permanent. The scale of car parking can be proportionally balanced and properly coordinated with the building's shape. 

C.9 Cart Type

This is a multi-leveled car parking system and is designed to park vehicles into each parking lots by conveying vehicles automatically with both a up-and-down lift and a parking cart. The carts independently installed on each parking level can retrieve vehicles from parking lots, and more than one lift move simultaneously for car parking/retrieval. This is one of most up-to-date mechanical parking systems with speedy car parking/retrieval and fits a large scale of car parking that can maximize the utilization of the underground space by installing many rows of the carts in the underground. 

6- Commercial Elevators

A- Commercial passenger elevators  

Commercial passenger elevators

A passenger elevator is designed to move people between a building's floors. Passenger elevators capacity is related to the available floor space. 

B- Freight elevators  

A freight elevator, or goods lift, is an elevator designed to carry goods, rather than passengers. Freight elevators are generally required to display a written notice in the car that the use by passengers is prohibited (though not necessarily illegal), though certain freight elevators allow dual use through the use of an inconspicuous riser. Freight elevators are typically larger and capable of carrying heavier loads than a passenger elevator, generally from 2,300 to 4,500 kg. Freight elevators may have manually operated doors, and often have rugged interior finishes to prevent damage while loading and unloading. Although hydraulic freight elevators exist, electric elevators are more energy efficient for the work of freight lifting. 

Freight elevators include the following classes: 

Freight elevators Classes

Class A: General Freight Loading

Where the load is distributed, the weight of any single piece is not more than 1/4 the capacity of the elevator and the load is handled on and off the car platform manually or by means of hand trucks. 

Class B: Motor Vehicle Loading

The freight elevator is used solely to carry automobile trucks or passenger automobiles up to the rated capacity of the elevator. 

Class C1: Industrial Truck Loading

A four-wheeled vehicle may be used to load and unload the elevator. The combined weight of the vehicle and the load cannot exceed the rated capacity and may be rolled onto the platform as a single unit. 

Class C2: Industrial Truck Loading

During loading and unloading, max load on the platform may be up to 150% of the rated capacity. This enables you to use a forklift to load a car with freight weighing up to the rated capacity. 

Class C3: Other forms of Industrial Truck Loading

During the loading and unloading process, the rated capacity must never be exceeded. 

C- Commercial Dumbwaiter  

Commercial Dumbwaiter

They are economic solution for moving material from floor to floor in a multi-level

commercial environment. They can carry loads up to 750 lbs. Commercial Dumbwaiter used to Save manpower, save space, save time, save energy and help avoid workplace injuries. Typical materials handled in a commercial environment can be Food, Dishes & Cutlery, Documents, Clothing, Carts or Shoes. Commercial Dumbwaiter can have one of the following types or configurations: 

Commercial Dumbwaiter Configurations

Forth: Elevators classification according to elevator location  

A- Outdoor Elevators   Common types of outdoor elevators are cargo elevators, platform elevators, and incline and vertical elevators. 

A.1 Observation elevator 

Observation elevator

The observation elevator puts the cab on the outside of the building. Glass-walled elevator cars allow passengers to view the cityscape or the building’s atrium as they travel. By eliminating the hoist ways, the observation elevator also offers owners, architects and builders valuable space-saving advantages. 

A.2 Incline Elevators 

Incline Elevators

Outdoor elevators built on an incline can also be used to transport passengers or goods. Incline elevators are most often recognized as passenger elevators called ski lifts. However, outdoor elevators that move cargo on an incline are generally constructed with a conveyor belt and most often seen when loading cargo on ships and some types of aircraft. 

A.3 Platform Elevators 

Platform Elevators

While it is possible to use platform elevators indoors they are generally classified as outdoor elevators because that is where they are most often used. Platform elevators usually are not enclosed by having a have a fence or gate running around the perimeter to keep cargo from slipping off during transport. Platform elevators usually use a system of pulleys as the working mechanism. Outdoor elevators consisting of a platform are most often used at new construction sites but they can also be used for such things as elevating workmen renovating the façade of a building or washing windows on a high-rise. 

A.4 Freight Elevators

Freight Elevators

Freight elevators are almost always outdoor elevators even though some smaller versions are designed for indoor use such as those used in warehouses. They are most often extremely heavy-duty and can facilitate a great amount of weight. This type of elevator can either be on an incline or vertical, but will most often be industrial grade to accommodate those heavy loads. In fact, the first type of elevator which comes to mind when thinking of outdoor elevators is actually freight elevators. 

B- Indoor elevatorsAll elevators installed inside a building which usually need a hoist ways and pits. 

Fifth: Elevators classification according to special uses  

A- Handicap Elevators  

Handicap Elevators

In reality, any type of elevator that can assist a handicapped person in going up and down various levels of the building could be considered a handicap elevator. However, specific types of elevators are manufactured with handicapped persons in mind. A good example of this would be a wheelchair lift that gets a handicapped person in and out of vans. The lift comes out the sliding doors and descends in order to allow the wheelchair on the platform. Then the lift is raised up and backs into the vehicle. Most city buses have this type of handicap elevators installed on them, but they are also manufactured for privately owned vehicles as well. Most handicap elevators within a home are electric elevators, but some are pneumatic vacuum models as well and operated by air pressure. Stairway lifts are also considered to be a type of handicap elevator and this type can either be installed on a straight stairway or a curved staircase. 

B- Grain Elevators

Grain Elevators

A grain elevator is a tower containing a bucket elevator, which scoops up, elevates, and then uses gravity to deposit grain in a silo or other storage facility. They can be classified as either “country” or “terminal” elevators, with terminal elevators further categorized as inland or export types. Operations other than storage, such as cleaning, drying, and blending, often are performed at elevators. The principal grains and oilseeds handled include wheat, corn, oats, rice, soybeans, and sorghum. 

C- Double-deck elevator  

Double-deck elevatorDouble-deck elevators save time and space in high-occupancy buildings by mounting one car upon another. One car stops at even floors and the other stops at the odd floors. Depending on their destination, passengers can mount one car in the lobby or take an escalator to a landing for the alternate car. 

D- Sky Lobby  

Sky Lobby

In very tall buildings, elevator efficiency can be increased by a system that combines express and local elevators. The express elevators stop at designated floors called sky lobbies. There, passengers can transfer to local elevators that will take them to their desired floor. By dividing the building into levels served by the express elevators, the local elevators can be stacked to occupy the same shaft space. That way, each zone can be served simultaneously by its own bank of local elevators.

F- Limited use / limited application     (LU/LA)

 Limited use / limited application  (LU/LA)

The limited-use, limited-application (LU/LA) elevator is a special purpose passenger elevator used infrequently, and which is exempt from many commercial regulations and accommodations. For example, a LU/LA is primarily meant to be handicapped accessible, and there might only be room for a single wheelchair and a standing passenger

In the next Topic, I will explain the Basic Elevator Components. So, please keep following. 

Note: these topics about elevators in this course EE-1: Beginner's electrical design course is an introduction only for beginners to know general basic information about

elevators as a type of Power loads. But in other levels of our electrical design courses, we will show and explain in detail the Elevator Loads Estimation calculations.