VTME dubai Rajan Samson Article Elevators For Improving Life Safety
VTME dubai Rajan Samson Article on Comparison of dedicated against common service elevators in hospitals
1. Building Design
Comparison of Dedicated and Swing
Public/Service Elevators in Hospitals
by Samson Rajan Babu
photos courtesy of Hydraulik–Liftsysteme Walter Mayer GmbH, InterMetro, Cambro,
Schindler, Lobby Solutions, Swisslog, Construction Specialties and Dural GmbH
Introduction N Access security controls
This article investigates the chal- N Key controls
lenges of swing public/service eleva- N Serves all floors, including base-
tors and the factors to consider while ments and mechanical floors
providing a dedicated service eleva- Typical Arrangements
tor. In a modern hospital project, A service elevator can be provided
architects recommend a variety of in several arrangements, such as:
elevator types: public elevators, bed N Dedicated service elevator: The ser-
service elevators, staff elevators, vice elevator is located away from
general-purpose goods elevators, the public elevators and has its
dumbwaiters, and both sterile and own service approach lobby and
soiled theater elevators. Architects staging areas. The elevator core
typically wish to reduce the number shape corresponds to deeper car
of elevator cores to the minimum types for the transport of stretch-
possible in order to gain more usable ers, carts, etc.
space. There is often a tendency to N Swing public/service elevator –
double the role of public elevators to common public lobby: The service
move materials, supplies and service/ elevator is among the public ele-
support personnel. It is also common vator group, and the main lobby is
for public elevators to be used to also used as a service lobby and
transport patients confined to beds staging area. The elevator core
and wheelchairs. shape could be for a standard,
Description wider passenger elevator car. This
A service (or “bed service”) eleva- shape cannot accommodate stretch-
tor allows the vertical transportation ers. Alternatively, the service ele-
Samson Rajan Babu is a of materials, supplies and miscella- vator core shape could be for the
senior vertical transporta- neous goods. It also helps segregate deeper car type, with the remain-
tion engineer for Burt Hill, ing public elevators for the wider
movement of tradespeople, service
a Stantec Co. He offers
and maintenance personnel on duty. car type. This results in a staggered
expert elevator traffic anal-
In a hospital, it could also be used to elevator core shape that could
ysis, group planning, vertical-
transportation system de-
transport non-ambulatory patients negatively affect the surrounding
sign, specification writing, confined to beds, wheelchairs and rentable area.
tender management, post- stretchers. N In rare cases, the entire public ele-
contract construction management and project Typical Features vator group and service elevator
execution quality control for elevator and escala- N Large payload are arranged in the deeper car type
tor systems. Babu is also responsible for inter- N Deeper car (to accommodate bed- to achieve a uniformly shaped
facing with other trades. He has 11 years’ working /stretcher-shaped items) elevator core. While a deeper car
experience in elevator/escalator group design, N Side-opening telescopic doors serves well for service traffic, it is
specification development, post contract, project
N Simple and sturdy cab finishes and not a preferred arrangement for
management, installation management, and project
flooring passenger traffic. Deeper car types
sales of elevators and escalators.
N Crash rails cause longer passenger transfer
Continued
52 | WWW.ELEVATORWORLD.COM | March 2011
2. Building Design Continued
times at each stop, affecting round-trip time. In addi- Hospital Traffic Movement
tion, the passengers stand as in a queue inside the In a hospital, there is a wide range of materials, equip-
deeper car, which is an undesirable feeling. ment and supplies that need to be transported to various
N Swing public/service elevator – rear service lobby: The floors through the service elevators (Figure 1). Operatives
service elevator is among the public elevator group but and service personnel also require service elevators to
has a through-type car with two car entrances at 90º. commute to upper floors. Materials and supplies are
The front entrance is used for passenger traffic, while different types that cannot be mixed but need dedicated
the rear entrance is used for service traffic. trips. Items such as hot food require rapid distribution.
Typical Control Systems Material movement within a hospital can be affected
N Independent control mode: Service elevators are usu- by manually operated carts and trolleys or automated
ally provided with independent key controls and card guided vehicles.
readers to take command of the elevator for service Typically, the following types of service/personnel move-
use. This is the ideal operation mode for service eleva- ments are observed within a hospital:
tors, with which the service traffic is handled separate N Patient beds and wheelchairs
from the public traffic. N Linen carts
N Rear-entrance operation mode: Service elevators adja- N Meal carts
cent to public elevators and/or part of public elevator N Hot food distribution
groups are provided with “group separation operation” N Nourishment distribution
controls and a dedicated set of car operating-panel N Housekeeping, stationery and administrative equipment
and hall-call stations, and indicators for rear-entrance supply trolley
operation. Using a “group separation control,” the pub- N Scan/portable medical equipment movement
lic elevator is removed from the group and becomes a N Pharmacy/clinical supply trolley
single service elevator. It then operates exclusively N Waste collection (medical and nonmedical) trolley
based on commands from the rear-entrance controls. N Sterile items supply trolley Continued
(a) Patient beds (b) Housekeeping trolleys (c) Meal delivery carts
(d) Dirty linen carts (e) Clean linen carts (f) Automated guided vehicles
Figure 1: Types of service traffic within a hospital
54 | WWW.ELEVATOR-WORLD.COM | March 2011
3. Building Design Continued
N Janitor, maintenance and support staff movement with a specific predetermined route to approach and exit the
tools and trolleys service elevator. This route is typically laid away from the
In addition to the general service traffic, non-ambulatory main circulation routes and calls for more time spent to
patients’ movement is also necessary to move patients to reach a destination, which is often directly above the origin.
treatment/scan areas and operation theaters. Here, two Additional costs: A dedicated service elevator adds to
to three attendants accompany a patient. Depending on the project’s investment, operating and maintenance costs.
the number of beds, transport cart sizes, dimensions and It also mandates additional expenses on the structural
volume of materials and various other operational factors, elevator core; mechanical, electrical and plumbing service;
the required number of elevator trips must be calculated, fire and life-safety equipment; communication systems; and
and the total duration of elevator usage for hospital traffic building-management equipment.
movement must be calculated. Swing Public/Service Elevators
Dedicated Service Elevator Concerns
Advantages Some concerns of healthcare planners about swing
Improved traffic flow: In large hospitals with a consid- public/service elevators include the following:
erable number of upper floors and high occupancy rates, N Public traffic into sanitized service zones: There is no
the service traffic is high. By segregating and diverting control of visitor movement, and visitors could penetrate
the service traffic to the dedicated service elevator, the other hospital zones. These are usually kept sanitized
public elevators’ performance is unaffected with regard and are prone to contamination from visitor traffic.
to waiting times and trip times, especially during peak N Cross infection between patients and visitors: Patients
hours. Also, public lobbies are clear of obstructions, sick with communicable diseases can infect unsuspect-
enabling faster public passenger transfers in and out of ing visitors. Similarly, visitors with or who recently had
elevator cars. Apart from everyday traffic, damage and communicable diseases can transfer germs to newborns
repair is restricted only to the dedicated service elevator, and patients with weak immune systems.
and “time lost in repair” does not affect the performance N Unpleasant experience and breach of privacy: For vis-
of the public elevator group. itors, looking at patients on wheelchairs/stretchers
Improved hygienic conditions: Patients within a hospi- could be an unpleasant experience. Similarly, a patient’s
tal have weak immune systems and are thus prone to privacy is breached when unknown visitors see the
infections. By using exclusive bed service elevators for patient, possibly causing embarrassment to the patient.
patient movement, infectious germs and contaminating N Tidiness and hygienic environment: General service
agents brought in by the visitors are restrained from traffic (materials, food, supplies, etc.) brings in debris,
spreading to the patients. Also, any undesirable personal dirt, odor, spillover and stains. When not cleaned and
hygiene practices of service elevator users is limited to sanitized properly, these can cause mold and fungi
the service elevator. Finally, improper disinfection and buildup inside the elevator car. Thus, a healthy envi-
sanitizing of car interiors, and dirt, mold and fungi buildup ronment cannot be guaranteed within general service
and odor inside a service elevator could otherwise affect elevator cars at all times.
a sick patient. N Injuries and health risks: General service traffic could
Contact/droplet/airborne germs are generally present leave behind sharp objects, fluid leaks and radioactive
in a common/public service elevator, as it carries sick objects inside the public car. Sharp objects could cause
patients. Such germs can infect visitors when they touch injuries to visitors and cause further infection. Haz-
contaminated surfaces and objects (such as handrails or ardous healthcare waste could leave behind traces of
push buttons). By using a dedicated bed service elevator, infectious agents and spread to visitors, causing fur-
visitors are protected against such infections. This also pro- ther infections.
tects visitors against hazardous wastes and sharp objects. Other concerns about these elevators are:
Disadvantages N Service elevators have larger capacities when com-
Larger floor plate: Depending on the preferred service pared to public elevators. However, a service elevator
elevator’s location within the plot limit, the floor plate is allowed to operate at a lower speed than public ele-
may need to be increased in order to accommodate the vators, only needing to travel between the terminal
service elevator cores, lobbies and staging area. A large floors within 60 seconds. However, when part of a
service lobby and staging area must be provided to match public elevator group, the “upgraded service elevator”
the various turning radii of items moved. Rentable space cannot be slower, but must operate at a high speed in
is lost to the dedicated service elevator. order to satisfy the criterion of travel time between
Restrictions on material and service personnel flow: destination floors. (The public elevators in a hospital
With a dedicated service elevator, the operatives should use must travel between the terminal floors within 24 sec-
56 | WWW.ELEVATOR-WORLD.COM | March 2011
4. onds.) In effect, this combination increases the initial elevator is part of a public elevator group, then any fire
equipment cost. at the public elevator area will shut down the eleva-
N Housekeeping, service and maintenance operatives tors, including the service/firefighter’s elevator. This
(with their tools and carts) must share the same lobby will deprive the firefighters of an effective means of
as the visitors do. Visitors find it difficult to move in vertical transportation for firefighting and rescuing.
and out of the lobby, and this increases passenger Advantages
transfer times. This also results in an untidy lobby. N Cost savings: Initial investment cost is reduced, and cost
N Depending on the codes followed for a specific project, savings are made by eliminating an additional service
there could be a risk of overloading the swing service/ elevator and the related elevator infrastructure equipment.
public elevator car beyond the machinery capacity. For Running costs pertaining to operating and maintaining
example, Japanese elevator codes (Figure 2) allow 3.75 an additional service elevator are also eliminated.
m2 for a 1000-kg capacity bed elevator. When used by N More rentable space: By doubling the usage of a public
the public, the same elevator (due to its larger car area) elevator as a service elevator, valuable rentable space
could be overloaded up to 80%. This could lead to a is freed on all floors.
very unsafe situation. Disadvantages
N Service elevators are required to handle large beds, N Cab interiors and entrance architraves of a public ele-
furniture, etc. For this purpose, the entrance door size vator could be invariably damaged (even with the use
(width and height) of a service elevator is quite differ- of protection pads) when used as a service elevator.
ent from that of public elevators. Hence, a service N When damaged, repair takes time and requires shut-
elevator’s entrance door stands out in a public eleva- down of the public elevator. Until repaired, it presents
tor lobby due to its unusually large size, (Figure 3). an inferior look to the public.
Increasing the entrance size of a public elevator to N Odor, dirt, trash and stains are usually left behind after
match that of a service elevator would only lead to service use. Continued
unnecessary equipment costs.
N Since service elevators handle large beds and other Car size (1800)
furniture, their lobbies must be spacious in order to
accommodate the turning radii with a sufficient working
Handrail
clearance (Figure 4). When the service elevator is part
Approximately 2440 with pump
of a public elevator group, the lobby needs to be much
attached to end of bed
Clear car size (2700)
wider and deeper when compared to a public-only 450 1000-1080
lobby width and depth. More rentable space is lost, Trolley/
2370
equipment
which is loss of revenue.
600 (500)
N It is always preferred to double the role of a service
elevator as a firefighter’s elevator. When there is a
dedicated service/firefighter’s elevator (away from the
public elevator group), it results in “redundancy by
location,” as any fire in the public elevator area will not
affect the service/firefighter’s elevator. However, if this
1370
Car size, Rated capacity Equ. rated capacity Actual capacity as
area as per JEA as per JEA as per EN 81-1 per CIBSE Guide D
1500 mm x 2500 mm
1000 kgs. (13 persons) 1830 kgs. (24 persons) 19 persons
3.75 sq. mtrs.
Width of space for attendants
Figure 2: Comparison of car areas according to Japanese and European codes
to turn bed 180 degrees
(3370)
4310 (3980)
Length of space for attendants
(a) Passenger elevator (b) Passenger elevator (c) Service elevator to turn bed 180 degrees
Figure 3: The larger entrance of a service elevator in a public elevator lobby Figure 4: Extra lobby width is required to accommodate the turning radius of
presents an odd look. a large, motorized bed.
March 2011 | ELEVATOR WORLD | 57
5. Building Design Continued
N Negative effects on the originally planned handling N Use heavy-duty floor tiles with good tile grip or check-
capacity and waiting time of the public elevator group. ered plate flooring within the elevator car.
N Under certain conditions (such as defective controls or N Use coved-end flooring to facilitate easy cleaning
a lost key), the service operatives may end up using the (Figure 5).
first available elevator in the public group for service N Use easy-to-clean, smooth stainless-steel finishes for
traffic. All the elevators in a public elevator group will cabin interiors.
then be exposed to these disadvantages. N Verify elevator interface requirements with automated
Design Considerations guided vehicles.
Dedicated Service Elevator N Allow for bumper/crash rails inside the car on all three
If planning a dedicated service elevator or bed service sides.
elevator, the following should be considered: N Allow for kick plates at the bottom level of the car to
N Based on number of floors and beds, and operational absorb tire impacts.
factors, estimate the required quantity and intensity of Swing Public/Service Elevators
bed, wheelchair, trolley and cart movements, and If planning a swing public/service (or a swing
other maintenance/service personnel movements. public/bed service) elevator, the following should be
N Estimate the “running elevator hours” consumed exclu- considered:
sively for bed/material movement. Justify the require- N Estimate the required quantity and intensity of move-
ment for a dedicated service elevator. ments and “running elevator hours” as described above.
N Estimate car floor size, car clear height according to If this figure is large, do not use a swing public/service
desired cart/trolley sizes and their quantity per trip, elevator.
and the size of the largest equipment moved through N Schedule the service trip timing so as not to clash with
the elevator. peak-hour public traffic.
N Estimate payload capacity according to the desired cart/ N Avoid hot food distribution, which can create intense
trolley loads per trip and the weight of the largest traffic within a short duration (usually within 20 min-
equipment moved through the elevator. utes). Instead, allow for devices at each floor to reheat
N Allow for a service entrance lobby with suitably sized the food.
staging and operating space. The lobby must be self- N For nonperishable items (such as linen and adminis-
contained without extending into other functional space. trative supplies), provide storage shelves at upper floors
N Allow for sufficient lobby width for the turning radius and replenish stock during off-peak hours.
of the equipment with the longest dimensions. N Do not also use the public entrance lobby for service
N Estimate door clear width and height according to the traffic. Always provide dedicated rear service entrance
largest equipment dimensional requirements. and a rear service lobby.
N Locate the service elevator core away from public ele- N Use special operating modes, communication devices,
vators to increase the redundancy level during fire delay alarms and visual indicators, forcing operators to
emergencies. use the swing public/service elevator sensibly and to
N Verify the availability and connecting lobby to the alter- return the elevator to public service promptly.
nate service elevator should the main one fail.
N Avoid dirt-catching, hard-to-clean crevices, recesses and
joints inside the car.
Figure 5: Coved-end flooring Figure 6: Card reader control inside elevator car
58 | WWW.ELEVATOR-WORLD.COM | March 2011
6. N Devise suitable operational procedures (forms) to con- N Maintain schedules for regular cleaning and sanitizing
trol and authorize the use of a public elevator as a service elevator cars. Conduct regular audits on schedule
service elevator (Figure 6). compliance and surprise checks on the car interiors.
N Allow for crash rails and permanent hooks at the top level Conclusion
of the car for removable car protection pads (Figure 7). A hospital is a space for the sick to recuperate, and it
Operation and Maintenance Considerations should provide a comfortable healing experience for pa-
In both dedicated and swing service elevators, imple- tients and chaperones. For visitors, a hospital is also a space
menting the following operational procedures can help that should be hygienic. For healthcare professionals, a hos-
organize the service traffic evenly and improve public pital should also be functional, and easy to use and maintain.
health and hygienic conditions within a hospital: A hospital operator cannot afford any shortcoming on
N Devise and implement material/service personnel move- patient comfort, hygiene or public health. This could be
ment policies and monitor compliance. Address issues detrimental to the business aspirations of the hospital.
such as authorized usage and approved timelines for Expert selection and arrangement of transportation and
service elevator usage, and record the duration of serv- circulation elements are extremely essential in order to
ice elevator usage. maintain high levels of patient comfort, patient privacy
N Include access security (card readers, passwords and and public health. As consumer demand and awareness
keys) for gaining exclusive command of elevator car for services and quality of services increase, it is the
(Figure 6). author’s understanding that a dedicated service elevator
N Include floor access security for sterile floors, burns- will soon become the norm of the healthcare industry.
References
unit floors, etc. [1] AIA Guidelines For Design And Construction Of Health Care Facilities: 2006.
N Always use fully covered trolleys and carts, and soak- [2] Health Technical Memorandum 08-02: Lifts: 2010.
[3] CIBSE Guide D: Transportation Systems in Buildings: 2005.
free disposal bags to transport loose or sharp objects. [4] Japanese Industrial Standard A 4301:1983: Sizes of car and hoist way of
Handle odor and stains securely and discreetly. elevators.
(b) Car protection pad
(c) Entrance protection pads
(a) Car with complete accessories: kick plate, handrail and crash rails
(d) Crash rail with handrail
Figure 7: Elevator car and entrance protection
March 2011 | ELEVATOR WORLD | 59