Elevator

:This article is about the transport device. For other meanings of the word, see Elevator (disambiguation).

Uses of elevators

Passenger service

A passenger elevator is designed to carry people and small packages.

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Passenger elevator capacity

Passenger elevators capacity is related to the available floor space. Generally passenger elevators are available in typical capacities from 1,500 to 5,000 lb (680 to 2,300 kg) in 500 lb (230 kg) increments. Generally passenger elevators in buildings 4 stories or less are hydraulic, however concerns with hydraulic elevators in recent years have limited their installations. In buildings up to 10 stories, electric elevators are likely to have speeds up to 300 ft/min (1.5 m/s), and above 10 stories speeds begin at 500 ft/min (2.5 m/s) up to about 1200 ft/min (6 m/s).

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Types of passenger elevators

Passenger elevators may be specialized for the service they perform, including: Hospital emergency (Code blue), front and rear entrances, double decker (2 cars on top of one another), and other uses. Cars may be ornate in their interior appearance, may have audio visual advertising, and may be provided with specialized recorded voice instructions. The concern for entrapping passengers requires all elevators to have communication connection to an outside 24 hour emergency service, automatic recall capability in a fire emergency, and special access for fire department use in a fire. Elevators are not an acceptable means of escape during a fire and should not be used by the Public for this purpose. Signs are required in most all US Jurisdictions to "USE STAIRS IN CASE OF FIRE."

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Residential elevators may be small enough for one person while some are large enough for more than a dozen.

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Wheelchair, or Platform lifts, a specialized type of elevator designed to move a wheelchair 6 ft (2 m) or less, often can accommodate just one person in a wheelchair at a time with a maximum load of 750 lb (340 kg).

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Freight elevators

A freight elevator is an elevator designed to carry goods, rather than passengers. (Passengers often accompany the freight, however.) Freight elevators are exempt from some of the ASME A17.1 code requirements, as defined by the words "not for public use." Freight Elevators or Service elevators may be exempt from some of the requirements for fire service. However, new installations would likely be required to comply with these requirements. Freight elevators are generally required to display a written notice in the car that the use by passengers is prohibited, though certain freight elevators allow dual use through the use of an inconspicuous riser.

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Freight elevators are typically larger and capable of carrying heavier loads than a passenger elevator, generally from 5,000 to 10,000 lb (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.

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A small freight elevator is often called a dumb waiter (see next section), often used for moving of small items such as dishes in a 2-story kitchen or books in a multi-story rack assembly. Passengers are never permitted on dumbwaiters. Dumbwaiters and other material lifts are required to conform to the related sections of the ASME A17.1 code in most U.S. and Canadian Jurisdictions.

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A specialized type of freight elevator is an Automobile Lift, used to move automobiles around a parking garage or other facility. These are material lifts by definition and are exempt from the ASME A17.1 requirements, but may have to comply with the requirements of ALI ALCTV if provided for in the local jurisdiction.

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Stage and Orchestra lifts are specialized lifts for use in the performing arts, and are exempt from the ASME A17.1 requirements. Local Jurisdictions may govern their use, installation and testing, however they are often left out of local code enforcement provisions due to their infrequent installation.

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Dumb waiter

A small box elevator designed for the carriage of lightweight freight is called a dumb waiter (or dumbwaiter). Dumbwaiters are required to comply with ASME A17.1 in most US and Canadian Jurisdictions.

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Dumbwaiters are generally driven by a small electric motor with a counterweight and their capacity is limited to about 750 lb (340 kg). They may also be hand operated using a roped pulley. Dumbwaiters are used extensively in the restaurant business (hence the name) and may also be used as book lifts in libraries, or to transport mail or similar items in an office tower.

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Material handling belts

A different kind of elevator is used to transport material. It generally consists of an inclined plane on which a conveyor belt runs. The conveyor often includes partitions to prevent the material from sliding backwards. These elevators are often used in industrial and agricultural applications.

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When such mechanisms (or spiral screws or pneumatic transport) are used to elevate grain for storage in large vertical silos, the entire structure is called a grain elevator.

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