Elevator 101
How do I choose an elevator?
Home elevators are not just for the disabled or the elderly. Smart homeowners realize that they are extremely functional for the modern lifestyle, and are still a relative bargain. The National Home Builders Association has identified elevators as a strategic element of a home, showing how home value can be increased by as much as 10%.
Most likely your experience into the obscure world of elevators has been at the office or a hotel by simply pushing a button and safely arriving at your destination. What other mode of transportation can a small child safely operate independently? As to be expected, elevators are complex and highly regulated.
As a potential elevator owner, you need to be aware of some basics, hence, Elevator 101. The code that regulates the manufacture and installation of elevators is called ASME A17.1 (American Society of Mechanical Engineers). This document is adopted by individual states with deletions, additions and amendments. Statutory authority is given to various jurisdictions to regulate and inspect elevators. In California, the amended and adopted ASME A17.1 becomes California Code of Regulation Title 8 (CCR T8). The two State authorities in California that regulate the manufacture and installation of elevators are the State of California and the City of Los Angeles. With respect to residential elevators, the state exempts residential elevators from inspection, while some cities including Los Angeles DO NOT. Therefore, when a homeowner lives outside the boundary of Los Angeles, a home elevator may not require an independent 3rd party inspection. This unique condition makes it incumbent upon the owner to have a certain level of knowledge of the regulations, which is where engaging only qualified, licensed elevator companies makes a lot of sense.
When considering your new elevator it is best to determine what type of suspension method you prefer and/or what your particular building conditions warrant. ASME A17.1 Section 5.3 (residential elevators) provide for 5 suspension methods. The most common methods for residential elevators are roped hydraulic, cable drum, and counterweight chain.
Roped Hydraulic: This method is primarily used when a remote power unit location is necessary. No other system will allow for the location of the “power unit” (power unit consists of motor, control valve, pump and oil reservoir) to be located remotely and not in line with the guide rails of the elevator.
Cable Drum: This method uses a geared machine to turn grooved steel drums that spool hoisting cable onto and off from the drum, i.e raise and lower. Advanced engineering design employs elevator controllers that use variable voltage and variable frequency which makes the geared drum machine smooth, step less and quite. With modern all position mount machines, nearly any building configuration can be accommodated. Further a geared VFAC machine will Never have a hydraulic leak.
Counterweight Chain: This method uses counterweights to offset the car or “cab” weight, allowing for the use of smaller motors and control drives. It is imperative that the motor mount in the overhead and in line with the guide rails. In jurisdictions such as Los Angeles, this method is not permitted. As with all chain and sprocket, the system will never be as quite and smooth as a cable.
Some other items to consider…
Speed: The maximum allowable speed per ASME A 17.1 Sec 5.3 is 40 Feet Per Minute
Capacity: Capacity is a function of platform area, per code. Residential elevator design allows for 62.5 lbs of loading per square foot. A 3’ X 4’ platform or 12 SF equals a capacity of 750 lbs.
Travel: This is the vertical height the elevator serves. It is limited to 50 feet.
Platform Size: Residential platform size is limited to 15 square feet in any configuration. That is not to say a larger size elevator can not be installed in a home, as it can. A larger platform size will change the design criteria for the elevator and generally the building requirements. In any case, the homeowner should make sure to engage a competent manufacturer well-versed in the ASME A 17.1 code and in local requirements.
Car Interior: This is where you, the homeowner can have a say how your elevator will look to its passengers. Nearly any material can be considered, even glass as long as it is compliant with ANSI Z97.1 code standards. The only limitation for the interior may be weight, as all elevators are weight-sensitive. Your manufacturer will be able to advise you regarding those issues.
