Posted .


Accessibility has become a more common topic in the design of buildings, both private residences and public/ commercial spaces as the population of North America ages. A key element of accessibility typically revolves around the use of some form of elevating device to transition from one level of a building to another as part of creating a barrier free path. Guidelines such as the American Disabilities Act (ADA) are often used to inform best practice for these types of accessibility designs in combination with specific codes that are applicable to different equipment options to accomplish the intent.

While traditional passenger elevators are well known to the public, there are a number of other types of elevating devices such as; stair lifts, inclined platform lifts, and vertical platform lifts that are more specifically applicable to accessibility and barrier free path design. These types of devices are used where the elevation change is greater than a ramp product would make sense for and before the travel distance, loads, or duty cycle would require stepping up to a full passenger elevator.

A ramp, for example, is often a good solution for travel distances under 24in and where the number of people needing accessibility is quite high but once the travel distance gets above 24in the 12in of length for each in of rise can become tougher to accommodate and quite expensive. Vertical platform lifts and other elevating devices then tend to become more economic and can save considerable floor space. While stairlifts can be used in numerous circumstances, but their use in commercial buildings is limited as they can’t typically accommodate a person and their wheelchair. Vertical Platform Lifts and Inclined Platform Lifts are more typical in commercial spaces to accommodate people with mobility challenges across the entire spectrum of need.

This article intends to look at a specific type of Vertical Platform Lift that is less well known and could help reduce the costs for accessibility in buildings that are not private residences. This type of lift configuration still preserves a high-quality aesthetic that would be above and beyond a typical vertical platform lift installation provides.

In some parts of the world a “lift” and an “elevator” can be considered the same thing; particularly in some parts of Europe. In Canada and the United Sates of America a lift, or more specifically a vertical platform lift (VPL) for accessibility, is defined by different codes than elevators. The codes that apply to lifts in Canada and the USA are CSA B355 and ASME A18.1, respectively, where elevators have a harmonized code that applies to both Canada and the USA under ASME A17.1/ CSA B44.

The main defining difference between a VPL and an Elevator is the type of operation. Specifically, an elevator is automatic and a lift is operated by constant pressure controls. Automatic operation is what most people are familiar with when it comes to elevating devices – you simply press the button and the device moves to the desired landing or level automatically while you wait (or as is more likely today, while you check your email or text messages on your phone). Constant pressure, on the other hand, requires that the user/ operator press and hold the control button continuously until the carriage arrives at the desired landing where the door or gate will then become unlocked and allow a passenger to enter the carriage area.

In addition to the difference in controls, VPL’s are more limited in the travel, weight capacity, and platform size than a passenger elevator due to the codes that apply. The history involved in deciding the amount of travel and sizes acceptable are not always clear but, from the perspective of this author, the VPL devices were specifically for single users or a user plus attendant and the carriages, with commensurate weight ratings, were then set up to match those requirements. The travel limitations were also considered with respect to the single user operation and thus additional travel to multi-stories is not considered logical for this type of equipment as more than one passenger would be unlikely to utilize the lift at a time. A nee for multiple mobility challenged people to utilize an elevating device simultaneously would then make a passenger elevator a more logical choice for the application.

That being said, there is a special classification of automatic elevator that can be used for commercial purposes, under section 5.2 of the ASME A17.1/ CSA B44 elevator code, called a LU/LA (Limited Use Limited Application); this elevator type is more limited, as the name implies, than a typical passenger elevator in size, weight capacity, and travel. Sometimes this type of elevating device is preferable as it has the automatic controls that might be more commonly understood by the public. It may also allow for voice activation where a lift would not have that ability.

A typical VPL, for commercial applications, has guard rails on the platform that are 42in high rather than a full height carriage that is required for elevator applications. A LU/LA elevator is no exception and has a full carriage requirement. The code for VPL’s does not, however, limit the guard rail height so a complete, full height, carriage could be attached to the platform. With a full height carriage, a user could certainly be excused for thinking a VPL looks identical to an elevator.

 

The rest of this article will focus on the differences between a full carriage VPL and LULA.

Floor Area: The floor area on a LU/LA is limited to 18 square feet by code and in the USA a VPL is also limited to 18 square feet but in Canada the code allows VPL’s to have as much as 21 square feet of floor space.

Drive types: Virtually any drive type can be attached to a VPL or LULA and the options available on the market are extensive. They range from simple screw type devices, hydraulic, and even MRL Traction devices.

Weight Capacity: Weight capacity for LU/LA devices is typically 1400lb and where a lift is 1400lb and 1050lb for Canada and the USA respectively, unless a variance is obtained.

Travel Speed: LU/LA elevators are limited to 0.15 m/s (ASME A17.1 section 5.2.1.16.4) travel speed by code where VPL’s can be equipped to operate at up to 0.25 m/s for Canada (CSA B355 section 4.3 ) and 0.15m/s for the USA (ASME A18.1 section 2.7.1) .

Travel: LU/LA elevators are limited to 25ft of travel in both Canada and the USA. VPL’s are limited to 23ft (CSA B355 4.2.1) and 14ft (ASME A18.1 section 2.7.1) in Canada and the USA respectively. Depending on the type of device, many jurisdictions in the USA will grant variances for full height carriage VPL’s up to the 25ft.

Stretcher Access/ Use: Depending on the building, there may still be a requirement from local authorities for the elevating and accessibility equipment to be deemed “stretcher ready”.

Section 3.5.4.1(1) of the ASME 17.1/ CSA B44 elevator code states that a stretcher, with a patient in the prone position, is 2010mm (79in) x 610mm (24in) in size. According to CSA B355 code the maximum platform area on an accessibility lift is 21 square feet (3024 square inches). Similarly, the limit on platform area in the USA, under ASME A18.1 code, has a limit of 18 square feet (2592 square inches).

Doing the math, both platforms can theoretically handle a stretcher if they are built with a long skinny platform. Whether a particular product can be arranged this way and still met the rest of the testing, stress, and code requirements is outside the scope of this article and will vary from product to product as well as manufacturer to manufacturer.

That being said, in both the Canadian or American case, the platform gets quite skinny and in the case of Canadian code an 80in long platform would then have a maximum width of 37.8in. If 24in of that is taken up by the stretcher then there would only be 13.8 inches left for an attendant. This is even further reduced in the USA where the platform width would only be 32.4in.  In both cases, this is quite limited and a likely scenario is that the stretcher would travel on its own without an attendant. While this is possible it may present safety risks that a paramedic or ambulance service could be concerned about.

 

At least one elevator authority has tried to provide guidance on this issue and document on their perspective can be viewed at the following link: http://www.municipalaffairs.alberta.ca/documents/ss/STANDATA/building/bci/06BCI028.pdf

Each local authority may have a different perspective and ultimately RAM would suggest you work with your local building permit office to determine if stretcher ready service is required, your local elevator branch to get their interpretation on what is acceptable, and apply for permits in advance of any construction so that there are no surprises.

Pit Depth: Depending on the product, the pit depth can be significantly reduces for a VPL with a full carriage and there are products on the market that will allow a full carriage on a VPL with no pit and only a small threshold ramp on the exterior of a shaft. This can be a significant advantage for retrofit applications where an existing foundation is already in place and digging a pit is problematic but accessibility is needed.

Operation: As noted earlier in this article the operation on a VPL is constant pressure where an elevator is automatic. Constant pressure operation can be confusing to some users that are more familiar with typical elevator equipment and this is one of the main reasons some developers and owners consider LU/LA or passenger elevators instead of VPL’s. However, VPL’s are typically equipped with signage to explain constant pressure usage and since they are primarily for accessibility many of the actual users are familiar with VPL’s operation.

Doors and Shaft Considerations: One of the other main differences between elevators and VPL applications is the shaft/ door arrangement. The way the safety code has been arranged for VPL’s the shaft construction and door arrangement is required to be “flush” on the interior. This flush arrangement avoids issues with shear hazards and eliminates the ability for persons, objects, or pets to remain in place on a landing threshold behind the door but not fully onboard the actual carriage before the door safety device is engaged and allows operation of the lift. This arrangement reduces the cost profile for the equipment and installation on a VPL when compared to a LU/LA.

Overhead Clearance: is the distance between the finished floor at the top landing and the ceiling inside if the shaft. For a  LU/LA the overhead clearance is typically a minimum of 134in whereas a VPL has no specific overhead clearance and is simply limited to practical human height restrictions and machine envelop. There are numerous products on the market that can be as little as 92in of overhead clearance. This can be a significant point for design consideration/ product selection, depending on the project and building arrangement. Building modification or retrofit projects often raise the profile of the overhead clearance of concern more frequently but even new building construction can be challenged by the overhead clearance required by a LU/LA device or a passenger elevator.

Aesthetics/ Appearance: One of the main issues clients, owners, and architects have with VPL’s is the appearance. The devices often look less refined and more utility based than a LU/LA or passenger elevator. In many applications, the code will require accessibility and the travel requirement between levels is excessive for a ramp of some kind but the building is also intended to look more polished. A full height carriage VPL with a full hoistway will give the accessibility device the same appearance as a LU/LA and in many cases other finishes, such as glass and stainless steel, can be employed to match up with other modern design aesthetics.

Initial Installation Cost: Depending on the exact configuration a full height carriage VPL will be between 30% to 50% less expensive than a LU/LA device for the equipment and installation. For some projects this can be substantial amounts of savings and also mean the difference between a building with accessibility that preserves the architectural appeal and one that simply meet the code.

Inspections, Service and Maintenance: Initial inspections are required on all commercial elevating product installation across the USA and Canada. Once an initial inspection has been passed, VPL’s and LU/LA’s typically have an annual inspection so the type of equipment selected does not affect costs initially. Once in operation, LU/LA’s typically require preventative maintenance inspections 4 times per year where VPL’s are typically once per year. Depending on the provider of the service and maintenance, this can be a substantial operating cost difference.

 

ARTICLE LINK