1. What are the different types of elevators available?

Hydraulic Type: Speeds from 100 FPM to 150 FPM. Higher speeds available but not recommended. Several types are available. Direct plunger type with the cylinder/plunger in the ground. Travel distance up to 50'-0". Holeless plunger type where the cylinder/plunger is within the hoistway. Travel distance up to 21'-0", but requires additional overhead height above top landing or additional pit below bottom landing from that of the direct plunger type. Roped Holeless type which is similar to the holeless except the elevator is suspended on hoist cables that are wrapped around a sheave mounted to the top of the plunger. Travel distance up to 70 to 80 feet and a standard overhead height and pit depth as that for the direct plunger type. Additional hoistway width is required from that of the standard direct plunger type. Traction Type: Speeds from 200 FPM to 2000 FPM. Higher speeds available for special high rise applications. Geared traction type utilizes a machine with a motor that turns a worm and gear (or helical gear assembly) to transmit motion to a drive sheave. Typically utilized for medium rise buildings from 4 stories to 28 stories. Speeds of 200 FPM to 450 FPM. Some manufacturers have speeds up to 500 FPM to 800 FPM for the helical geared application. Gearless traction type utilizes a machine where the drive sheave is mounted directly to the motor. (Gearless = No Gears). Used for high rise applications from 12 floors on up. Speed from 500 FPM to 2000 FPM or more for special high rise applications.

2. How do I know when to use a traction type elevator or a hydraulictype elevator

Hydraulic elevators are designed for low-rise and low-use applications. They are ideal for almost any type of two story building including offices, hospitals, museums, parking structures, hotels, etc. It is when the building is three stories or more that a closer look at the type of elevator must be considered. One of the deciding factors on elevator selection is “how busy” will the elevator be during the day. Some building types such as offices, courts, hospitals and classrooms generate traffic patterns that require the elevators to be in motion nearly all day long. Traction elevators should be considered for these types of buildings. Other building types such as apartments, condominiums, motels and some types of parking structures have periodic peak traffic periods and the elevators are at rest a good portion of the day. Hydraulic elevators are appropriate for this application for buildings up to five or six floors. So, what is meant by “how busy?” Hydraulic elevators should be kept to a maximum of 60 up-starts per hour. A single up-start is every time the elevator starts to move in the up direction. This is the only time it starts the motor and pump. The elevator moves in the down direction by opening a valve and allowing gravity to push the hydraulic fluid back to the storage tank. The greater the building population and the higher the number of floors served, the more up-starts are made by the elevator. When hydraulic elevator systems approach this 60 up-start threshold, the hydraulic fluid heats-up and the operation of the elevator becomes sporadic with poor stopping accuracy and poor ride quality as well as developing the smell of oil in the car and lobby. Overheating of the hydraulic system prematurely deteriorates components which will cause break-downs and those ugly “Out Of Service” signs on the elevator doors. Other factors to consider are: Investment Type: Will the building be developed for a long-term investment or is it simply a speculative short-term investment? A wise long-term investment will select the traction elevator equipment over the hydraulic when either will provide acceptable service. Perceived Quality: Dependent on the entire quality of the project with regard to construction, location, finishes, demand for rent and tenant target, the elevator systems must coincide with the intended overall quality of the project. Hydraulic elevators do not present a high quality image and if such is desired, traction elevators should be considered. Only traction elevators will present a perceived quality with its superior performance in ride quality, noise level and overall speed. A general rule that can be used is : For any two story building; Use hydraulic elevators. For any building over six floors; Consider the use of traction elevators. For apartments, condos and motels, up to six floors; Hydraulic elevators may be acceptable. For offices, hospitals, classrooms and courts with heavy populations and over two stories; Consideration should be given to using traction elevators. For long-term investment, high quality and prestigious projects; Traction elevators should be considered. A thorough traffic analysis should be conducted for those conditions that are borderline.

3. What is meant by “Proprietary Control System” and why should I be concerned?

Any system that is based on a microprocessor must have software that gives it instructions on what to do. The way a manufacturer does this is considered a trade secret since it requires a lot of time and effort to engineer this. The buzz word for this software is "Source Code." This is typically proprietary with all elevator manufacturers. The issue is really an issue of diagnostics. Proprietary diagnostics would only allow the manufacturer to diagnose problems by retrieval of fault codes. The diagnostics also allow adjustment of control parameters and performance of safety test. These systems can be made Non-Proprietary by supplying a laptop computer, hand-held tool with display, or built in keyboard, pad and display. This and the appropriate passwords and documentation on adjustments and fault diagnosis. Non-Proprietary Diagnostics allows alternate elevator contractors to provide maintenance should the manufacturer's performance be less than expected. This also minimizes the Owner being held hostage by a manufacturer who can dictate their maintenance price and say "Who else are you going to get to work on this equipment?" The use of these diagnostic capabilities should only be utilized by a professionally trained elevator mechanic familiar with the brand and type of equipment.

4. When is a dedicated service elevator required for an office building?

Industry standard criteria dictates that a typical multi-tenant office building requires a dedicated service elevator when the total building area approaches 250,000 GSF or when specific tenant needs warrant such for buildings having less than 250,000 GSF. Additional dedicated service elevators are required for each increment of 250,000 GSF. Unless there is a specific requirement for a dedicated service elevator, most buildings having less than 250,000 GSF can satisfactorily operate with a part time service elevator (swing car) that provides passenger service as its primary duty and service needs during off passenger peak periods.

5. Are glass elevator doors permitted?

Glass elevator doors are permitted when the building code does not require the hoistway enclosure to be constructed with a fire rating. Glass elevator doors are not fire rated and cannot provide the fire protective measures required when installed in a fire rated hoistway.

6. Do observation elevator car enclosures require guardrails in addition  to handrails?

The elevator code requires that the lower portion of the enclosure be guarded so as to provide adequate protection should the glass panels break or be dislodged. Specific detailed requirements are not provided in the code. The code does suggest that it is best to have a solid panel from floor to 42" above the floor to provide this added protection to passengers. Each local enforcing jurisdiction may have specific requirements for the guarded protection which maybe conveyed to you during plan check. The solid panel up to 42" provides an excellent means of modesty for women in skirts.

7. How much lighting is required on escalator steps?

The landing plates and steps of an escalator must be provided with a minimum of 5 foot candles for the full length of the escalator travel. If the normal building lighting in the area of the escalators cannot meet this requirement, step tread lighting or under handrail lighting can be providedby many of the escalator manufacturers.

If you have any additional questions, concerns or comments, please feel free to call, fax, write
or E-Mail us directly. We look forward to hearing from you.

This site will be routinely updated with new questions, solutions and information.
Come back and visit us often!