lift

LIFT

lift• For multi- storeyed buildings the installation of lifts is a

must to avoid fatigue in climbing up the stairs and for quick vertical circulation between different floors.

• The provision of lifts in a building is a highly specialised job.

• A vertical hat with openings at the floor level is provided.

• The shaft is located at a suitable place e.g. by the side of the stair or within the open well of a stiar.

• The shaft extends below the ground floor to accomodate the spring buffers for low speed lifts and hydraulic buffers high speed lifts.

• Usually a machine room (control room) is located at the top of the left shaft for housing equipment and accessories.

• It can be at the bottom by the side of the shaft.

• The size of the machine room is normally 4 m x 3 m x 2.5 m.

• Floors or machine room should be designed to carry a load or not less than 500 Kg/m

• Previously collapsible doors were provided both for the lift car (cage) and for the opening in the shaft at the floor level.

• Now a days flush doors of sliding type are provided.

Types of lift

1) Hydraulic lift

2) Electric lift

3) Passenger lift

4) Goods lift

Components of lift

1) Control room

2) guides

3) lift car

4) counter weight

5) control panel

6) lift pit

7) Buffer

8) Hoist way

9) hoist rope

Space Requirements

Passanger lift

DESIGN CONSIDERATIONS FOR LIFT

• Two important aspects in lift design are

a. Quantity of service

b. Quality of service

a. Quantity of service

• “Quantity of service” means passenger handling capacity of lift.

• During peak hours, the number of passengers which a lift can handle in 5 minutes time is taken as passenger handling capacity (H).

• It is expressed as percentage of total number of persons living in the building.

Class of occupancy H (percent)

Residential building

Office for single purpose

Office for multiple purpose

5

15 – 25

10 - 15

b. Quality of service

• The waiting time for lift by passengers on different floors is expressed as quality of service.

Quality of service(WAITING INTERVAL)

RATING

20-25 Seconds

30-35 Seconds

35-40 Seconds

40-45 Seconds

over 45 Seconds

Excellent

Good

Fair

Poor

unsatisfactory

Handling capacity

H= 300 x Q x 100

T x P

Where,

H = Handling capacity for 5 minute

Q = average number of passengers carried in car

T = waiting interval (sec.)

P = total population to be handled

Waiting interval

T = Rf

N

where,

T = Waiting interval (sec.)

Rf = Round trip time

N = No. of lifts

Occupant load :

Occupant load = gross area (m2)

person

Sr. No.

occupancy Occupant load gross area in m2 / person

1.

2.

3.

4.

5.

6.

7.

Residential

Educational

Institutional

Assembly hall with seats

Business and industrial

Storage

hazardous

12.5

4

15

0.6

10

30

10