Technology in ArchitectureLecture 9 Vertical TransportationElevators Design ConsiderationsElevator Selection ParametersExample Problem

Vertical Transportation

ClassificationElevatorsPassengerFreightSpecial service

Escalators

TypesElevatorstractiongearless medium-high speed passengergeared low speed passengerhydraulicplungerhole-lessroped

Performance CriteriaIdeal Performance:minimum waiting timecomfortable accelerationrapid transportationsmooth/rapid slowingaccurate levelingrapid loading/unloadingquick/quiet door operationgood visual travel direction/floor indicatorseasily operated controlscomfortable lightingreliable emergency equipmentsmooth/safe operation of mechanical equipment

Codes and StandardsANSI/ASME Code A17.1

NFPA 101 Life Safety CodeNFPA 70 ElectricalANSI A117.1 Barrier Free

Elevator Design Considerations

Passenger Elevator ComponentsTraction Elevatorcarcableselevator machinecontrolscounterweighthoistwayrailspenthousepit

S: p. 1395, F.31.1

Traction Elevator ComponentsMachine room8-6 minimum clear

Bottom of Beam (OH)17-6 206

Travelnumber of floors

Pit (P)10-1 11-5S: p. 1439, F.31.29

Passenger Elevator ComponentsHydrauliccarplunger/piston/jackelevator machinecontrolshoistwayrailspenthouse/headwaypit

S: p. 1400, F.31.5

Hydraulic Elevator ComponentsMachine room7-9 minimum clear

Bottom of Beam (OH)12-0 123

Pit (P)/Plunger4-0Travel +2-6S: p. 1402, F.31.6

Design ConsiderationsDoor openings>3-6 for simultaneous loading/unloading

Design ConsiderationsDoorssingle slide (24-36)center opening (42-60)two-speed, side opening (42)two-speed, center opening (60)S: p. 1406, F.31.12

Elevator Selection Parameters

DefinitionsInterval (I) or lobby dispatch timeaverage time between departure of cars from lobby

Waiting timeaverage time spent by a passenger between arriving in the lobby and leaving the lobby in a carequals (0.6 x I)S: p. 1421, T.31.4

DefinitionsCar passenger capacity (p)passengers per car

S: p. 1422, T.31.5

DefinitionsHandling Capacity (HC)maximum number of passengers handled in a 5 minute periodwhen expressed as a percentage of the building population it is called percent handling capacity (PHC)

HC= 300(p) IS: p. 1422, T.31.6

DefinitionsAverage trip time (AVTRP)average time from passengers from arriving in lobby to leaving car at upper floor

Note: car size floor to floor heightS: p. 1424, F.31.20

DefinitionsRound-trip time (RT)average time required for a car to make a round trip

S: p. 1425, F.31.21

ParametersBuilding populationtypical area per personbased on net area and building type

S: p. 1423, T.31.7

ParametersOffice building efficiencynet usable area as a percentage of gross area

S: p. 1423, T.31.8

ParametersElevator equipment recommendationsbuilding typecar capacityrisespeed

S: p. 1432, T.31.9

Sizing EquationsHandling capacity (HC): HC=300p/I

Interval (I): I=RT/N

5-min. handling capacity (h): h=300p/RT

Number of cars (N): N=HC/h

Elevator Design Example

Example ProblemDesign an elevator system for a 10 story, single purpose tenant, office building that provides an good level of service.

Construction level is normal

Floor height: 12-0 floor to floor

Floor area: 15,000 net square feet (nsf) each

1. Determine Percent Handling Capacity (PHC)Office building Investment

range 11.5-13 %say 12%PHC=0.12S: p. 1422, T.31.6

2. Determine Interval (I)Office building Good service

I=25-29 secS: p. 1421, T.31.4

3. Determine Building PopulationOffice building Single tenantNormal construction

range 90-110 sf/personsay 100 sf/person

Pop= 9 floors@15,000 nsf 100sf/personPop=1350 peopleS: p. 1423, T.31.7

4. Determine Handling Capacity (HC)PHC=0.12 HC=0.12 x 1350 people

HC= 162 people

5. Determine Rise & Select Car9 floors (above lobby)12-0 floor-floor

Rise=9 x 12-0Rise=108

Select Car:2500# car@400 fpmS: p. 1432, T.31.9

6. Determine Average Trip Time (AVTRP)12-0 floor-floor2500# car400 fpm9 floors

AVTRP= 64 secS: p. 1425, F.31.21

7. Determine Round Trip Time (RT)12-0 floor-floor2500# car9 floors 400 fpm

RT= 112 secS: p. 1428, F.31.23

8. Verify Single Car Capacity (p)2500# car

p= 13 peopleS: p. 1422, T.31.5

9. Determine 5-minute Handling Capacity (h)h=300p/RT

h= 300 x 13/112

h= 34.8 people

10. Determine number of cars (N)N=HC/h

N= 162/34.8

N= 4.7 cars say 5 cars

11. Confirm Interval (I)I=RT/N

I= 112/5

I= 22.4 sec

Required I 25-29 sec

Design exceeds performance requirements

12. Repeat Until Performance CompliesTry 4 cars (2500 lbs., 400 fpm)

11. (Re)Confirm Interval (I)I=RT/N

I= 112/4

I= 28 sec

Required I 25-29 sec

Design meets performance requirements

12. Repeat Until Performance CompliesPerformance is in compliance

Use 4 cars (2500 lbs., 400 fpm)

Elevator Lobby Requirements

Lobby ParametersProximity to other carssingle zonemultizoneProximity to emergency exits/egress stairsAdjacent to main lobby

S: p. 1438, F.31.27

Lobby SizingSize based on peak interval15 or 20 minute peak time5 sf/person

From previous example using 15 minute peak

h=34.8 people/5-min. 104.4 people/15 min.

Area= 104.4 people x 5 sf/person = 522 sf