Motors & Equipment

 
Low-energy Elevators
  
 
 

Definition
A proprietary low energy elevator that utilizes an axial synchronous AC motor design with a gearless drive system.

 
Building Use
bullet apartments
bullet commercial buildings
 
 
Building Type
bullet new


Development
Status

bullet new technology

Description
Traditional elevators systems are either traction-based for highrise buildings) or hydraulic-based (for lowrise buildings). Traction based systems are usually located in a penthouse machine room above the highest occupied floor. The rooftop location can impose height restrictions on buildings and often interferes with architectural features. The location of rooftop elevator machine rooms requires that clearances must be left through the roof deck for cables and wiring which are known to be areas of high air leakage. Hydraulic elevators utilize hydraulic cylinders to lift cabs from floor to floor. The hydraulic cylinder, hydraulic fluid reservoir and pressurizing equipment are located under the elevator shaft in an excavation under the building. Hydraulic elevators are often associated with slow, bouncing, movement. Hydraulic elevator fluid is extremely toxic and if spilled or leaked represents a significant environmental risk. The high starting amperage requirements of hydraulic elevators can cause flicker throughout a building's electrical system.

A proprietary elevating system has been developed that utilizes an AC, axial synchronous, gearless motor integrated with a traction sheave, brake flange and rotor. This single device hoists an elevator cab up to 10 landings in a fast, smooth movement that requires significantly less electricity than standard elevating systems. The hoisting equipment is so compact that it can be fitted into the elevator shaft. This eliminates the need for an elevator machine room on the roof of the building, simplifies design and construction and eases concerns regarding height restrictions. The system transfers reaction loads from the elevator hoisting equipment to the foundation of the building rather than the structure surrounding the hoisting equipment. This minimizes structural loading and design requirements for buildings where conventional traction equipment might have otherwise been installed. The space requirements are significantly less than standard equipment and operate at cooler temperatures. The absence of hydraulic fluid also negates the environmental risk of the elevating system. 

All control and logic systems are contained in a cabinet placed in a small machine room adjacent to the elevator hoist way at the top landing or contained within the front wall of the hoist way depending on the type of elevator system. 

The gearless elevators are available as simplex or duplex installations for 2 to 10 landings with up to 80 feet of track and they operate at 200 fpm. A 1650 mm-deep elevator pit is required. A minimum overhead distance, from the last landing to underside of the roof structure, of 3825 mm is required. This may, depending on floor-to-floor height, result in a small projection of elevator shaft above the roof.

The high efficiency motor set uses approximately 25% less energy than hydraulic elevators and approximately 50% of the energy required by traction elevators. The new elevating system can also reduce the amount of air leakage in buildings. The installation of the motor-drive set in the elevator shaft allows the roof thermal, moisture, air and vapour barriers to be made continous across the top of the building. Conventional elevator machine rooms are areas where substantial air leakage and heat loss from the building occurs. The prevention of air leakage in this location also helps to reduce unwanted air movement throughout the building.

Contributing Expert
Duncan Hill
Research Division
Canada Mortgage and Housing Corporation
700 Montréal Road
Ottawa, ON
Canada  K1A 0P7
tel 1 613 748 2984
fax 1 613 748 2415
dhill@cmhc-schl.gc.ca
http://www.cmhc-schl.gc.ca/Research/HighRise

   
Benefits
bullet reduces energy consumption by up to 50% when compared to traction elevators and up to 75% when compared with hydraulic elevators 
bullet reduces operating costs
bullet eliminates hydraulic fluid 
bullet reduces size of wiring, switch gear and emergency generator requirements
bullet simplifies design and construction
bullet reduces noise levels
 
Limitations
bullet number of landings served: 10 or fewer

Experience and Application
Low energy elevating systems have been installed in new buildings in the Toronto area since 1998.

Cost
The cost of low-energy-elevating systems is less than conventional systems. The simpler design, construction and installation requirements for this proprietary system can reduce associated costs. Manufacturer supplied cost estimates are provided below:

AC Gearless
Building Cost: C$65,579
Lifecycle Cost (5 year): C$3,520
Total Ownership Cost: C$69,099
Annual Energy Use: C$704

Hydraulic
Building Cost: C$74,354
Lifecycle Cost (5 year): C$15,328
Total Ownership Cost: C$89,682
Annual Energy Use: C$3,065

Traction
Building Cost: C$77,481
Lifecycle Cost (5 year): C$7,793
Total Ownership Cost: C$85,275
Annual Energy Use: C$1,558

Note: manufacturer supplied estimates. Costs will vary from building to building.

Example Manufacturers
Montgomery-KONE Elevator
80 Horner Avenue
Toronto, ON
Canada  M8Z 4X9
tel 1 800 956 5663
http://www.kone.com/

 
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