Video summary

07. Circulación Mecánica Vertical - Cátedra B. Garzón

Main summary

Key takeaways

Educational

Main ideas and concepts (Vertical Mechanical Circulation / Elevators & related systems)

  • Topic of the class: Vertical mechanical circulation in buildings—how people and goods are transported between different levels using mechanical systems.
  • Definition: Vertical mechanical circulation is the set of elements that transport people or objects across a building’s floors.
  • Cost relevance: Elevator-related equipment cost is estimated at ~10%–15% of the total building cost, so selection must consider many technical and design aspects.

Core classifications mentioned

By type of equipment / use

  • Passenger elevators
  • Freight / cargo elevators
  • Escalators
  • Ramps / vehicle ramps (mentioned as part of broader circulation context)

By machinery / drive

  • Electric / traction elevators
  • Hydraulic elevators

By presence of a machine room

  • With machine room
  • Without machine room

Methodology / instruction-like content (lecture structure + calculations + design requirements)

A) Lecture structure (sections the class will cover)

  1. Definition and historical background
  2. Classification of elevators
  3. Different types of sensors
  4. Escalators and freight elevators
  5. Sensor arrangement and minimum service requirements
  6. Elevator calculations
  7. A worked calculation example
  8. Construction parameters and regulatory bodies

B) Historical development (key timeline concepts)

  • ~1500 BC (Egypt): ramps and ropes used to move stone blocks.
  • 236 BC: Archimedes’ influence:
    • pulley/rope systems moved by man
    • screw mechanism (Archimedes screw / “endless screw”)
  • 80 BC: elevator use in the Flavian Colosseum (for gladiators and wild beasts).
  • 1405 (Middle Ages): elevating people/supplies to isolated places (castles/monasteries) using rope + drum.
  • 1793: first elevator based on screw transmission (Ivan Y. Banjul), installed in Winter Palace, Saint Petersburg.
  • 1800–1835: steam engine enables steam-powered elevator devices (e.g., mine coal lifting).
  • 1845: first hydraulic elevator (Will and Foundson) using traction pulley + counterweight.
  • 1852: first elevator safety system (Liza Grave Bautice)—stops the elevator if the support cable breaks.
  • 1857: first steam-powered passenger elevator with safety brake (New York).
  • 1867: hydraulic piston passenger elevator shown in Paris (Leo Books).
  • 1870: electric elevator invention (Werner Banquinas); “elevator building” concept appears in Chicago.
  • 1885: skyscraper-era evolution enabled by elevators (New York).
  • 1887: self-closing doors (Alexander Minds).
  • 1889: elevator sensors installed in the Eiffel Tower (noted as eight mechanical sensors).
  • 1905: Otis Elevator Company invented first memory control system (reducing need for access control).
  • 1908: elevator installed at the Investigating Building in New York.
  • Ongoing note: development continues across varied sensor technologies and mechanical circulation forms.

C) Sensor / elevator classification details (as presented)

1) Sensors classified by machinery they use

  • Electric
  • Traction
  • Hydraulic
  • May have machine room or not

2) Sensors classified by function / use

Passenger elevators can include:

  • Residential
  • Commercial
  • Office
  • Hotel
  • Bed lifts
  • Stretcher lifts

Freight elevators can include:

  • Freight
  • Mini-freight
  • Car lifts
  • Hydraulic platforms

D) Machine room definition + requirements (minimum indispensable requirements)

Machine room definition

A room intended to house:

  • drive machinery
  • control panels
  • other implements governing elevator / freight elevator operation

Typical/required design constraints mentioned

  • Top floor terrace above the building:
    • must be built with non-combustible materials
  • Enclosures must not be receptacles for liquids
  • Minimum height: > 2 meters
  • Surface sizing constraints:
    • surfaces must exceed 3× shaft area, or be 8 m² for elevators with minimum side 2.20 m
  • Temperature requirement: ventilation and lighting must maintain < 35°C
  • Contents (only elevator-related): motor, contactors, control panel, pulleys, ventilation, plus elevator equipment
  • No unrelated elements should be located there

E) Traction (electric/traction) elevators: components + pros/cons (design tradeoffs)

Main structural idea (as described)

  • Car on one side + counterweight on the other
  • Electric motor moves them upward/downward
  • Machine room can be:
    • at top or bottom of shaft

Components mentioned

  • Rails/guides, sliders, cables, counterweights, safety system
  • Doors
  • Car enclosure
  • Overtravel / undertravel
  • Machine room
  • Traction-specific elements:
    • motor, pulley, car frame, car door, guides
    • counterweight + buffer
    • extraction sensors

Machine room below (vs above): disadvantages / advantages

  • Advantages:
    • avoids cabin on roof or pulley room
  • Disadvantages (given):
    • higher cost
    • greater structural loads
    • higher energy consumption
    • poorer ventilation
    • higher operating costs

Traction without machine room (gear/pulley redesign)

  • Eliminates machine room by mounting redesigned machinery in the shaft.
  • Advantages (given):
    • high building design flexibility
    • profitability of investment
    • construction cost savings
    • better energy efficiency
    • quieter operation
    • better comfort
    • more precise leveling
  • Disadvantages (given):
    • higher installation and maintenance costs
    • more noise source

F) Hydraulic elevators: mechanism + components + types

Basic mechanism (how it works)

  • Cabin movement via a piston
  • Oil injected/extracted under pressure may extend inside a tube
  • Requires a borehole roughly equal to cabin travel depth
  • Limited to low-rise buildings because piston height ≈ building height
  • Drilling tech can enable longer travel by solving deep excavation constraints

Basic components listed

  • Piston below cabin
  • Cylinder housing the piston in deep excavation
  • Hydraulic pump driven by three-phase motor
  • Valve system
  • Fluid reservoir

Two-piston explanation (fluid mechanics concept)

  • Two pistons connected through a leak-free tube with incompressible fluid:
    • large area / small area
  • Press one → forces the other to rise → cabin lifts

Hydraulic types by drive method

Differential drive

  • (Presented as a separate type; described more fully under direct vs differential below.)

Direct drive

  • Direct drive: 1 cm piston travel → 1 cm cabin travel
    • recommended for short travel distances and heavy loads
    • “no steel cables” mentioned
    • safety via valve that shuts off oil flow on hydraulic circuit break
    • recommended when travel distance < 4 m
    • variants:
      • Central direct drive: piston centered in shaft with perforation + protective casing
      • Lateral direct drive: piston at one side; perforation may/may not exist

Differential drive

  • 1 cm piston travel → 2 cm cabin travel
  • Uses pulley + cable system doubling cabin travel distance
  • Installs piston on side, so it doesn’t require a deep pit
  • Ideal for freight elevators and long travel > 4 m
  • Machine room may or may not exist (if present, can be placed with a distance rule: 15 m from shaft)

Hydraulic advantages listed for systems without machine room (selected points)

  • Avoid machine rooms (help crown design)
  • Smaller, quieter drive unit placed far from shaft
  • Eliminates counterweight systems (reduces space)
  • No wall discharges (vibrations reduced by routing to base)
  • Smooth acceleration/braking
  • Precise leveling
  • Low maintenance (constant lubrication)
  • Cabin moves to nearest low level
  • Can be installed in confined spaces if electrical issues occur

G) Safety elements classification (as described)

  • Speed governor
  • Safety gear
  • Buffers

Speed governor concept described

  • Two pulleys:
    • one in machine room
    • one aligned vertically
  • Steel cable passes through; ends connected to:
    • fixed point of frame
    • lever system to trigger safety
Parachute systems
  • Instantaneous: nominal speed ≤ 60 m/min
  • Progressive: higher speeds using wedges or rollers near guide rails
Dampers
  • energy storage or spring-type for low speeds
  • energy dissipation or hydraulic for high speeds

H) Application examples of vertical circulation (design concepts + instances)

Inclined elevator examples

  • Luxor building (adapted to building shape)
  • Pyramidal hotel (panoramic elevators)
    • external glass elevator on Blood Mountain route (China)
    • ~330 m high; up to 50 people/trip; ~1-minute delay to summit

Panoramic gondola / cabin lift example

  • Sky View (Stockholm) gondola lift
    • 100 m journey; two spherical cabins

Multi-function elevators (“twin/trim” concept)

  • Two cabins per shaft
  • Increases transport capacity with less construction volume
  • Saves up to 25% of cabin shaft space

I) Elevators specialized by function (examples)

  • Hospital elevators: transport people, staff, and instruments (stretchers, wheelchairs, food carts, laundry carts)

  • Vehicle transport devices:

    • car lifts in garages: vertical-only, vertical+horizontal, rotating cabins
    • pneumatic elevators: pressure depression lifts; mainly for homes
  • Accessibility requirement (motor disability) via Law 4314 (as stated):
    • cabin entry / maneuverability for wheelchair at least 1.0 m × 1.25 m
    • wheelchair maneuver within 15 m radius on landing
    • handrails recommended around perimeter at ~1 m height
    • aim: independent movement within cabin and freedom of movement (with/without assistance)

J) Escalators: functional structure

  • Continuous belts with:
    • handrails
    • steps moving at the same speed
  • Components:
    • Upper part: heads, step entrances, traction mechanism, motor, control system
    • Middle part: balustrade, steps, guides, supports (can be variable length within limits)
    • Lower part: heads, return system with tensioning, tread, step entrances
  • Requirements mentioned:
    • plan intermediate floor openings
    • consider structural load
    • ensure space at top/bottom for motor and belt gearing

K) Grouping / arrangement of elevator “banks” and sensor cores (rules presented)

General layout concepts (when two cabins exist)

  • Facing each other:
    • separation distance = 1.5 to 2× shaft separation size
    • pairing ensures exit separation from enclosure with size ≈ elevator shaft size
  • Parallel configuration with corridor between them

“Three elevator” grouping concepts

  • Facing each other:
    • one cabin opposite 12 stops
    • separation ≈ depth of elevator shaft
  • Or row of three adjacent elevators:
    • cabin exit separation = 15× shaft depth
    • minimum 18 m

“Four elevator” grouping concepts

  • Set of 4 cabins facing each other; open/closed on one side:
    • landing width = 15 to 2× shaft depth
  • Or side-by-side 4 cabins:
    • arrival distance = 1.5× elevator shaft distance
    • both sides left open

“Five/six/eight” group concepts (as described)

  • Six cabins: similarly paired facing each other or in a row, keeping separate circulation spaces
  • Up to eight cabins:
    • facing each other: both sides open; arrival distance = 2× shaft size

Corridor separation grouping

  • Group of two cabins separated by corridor
  • Group of four cabins facing each other at arrival landing:
    • separation rule = 15 to 2× elevator shaft depth

Exceptional arrangements

  • Cabins may be different shapes to match project needs:
    • facing each other at converging angle
    • core of elevators sharing the same landing
    • curved arrangement following curve geometry
  • Circulation recommendation:
    • exit from elevator shaft on the wider side for better circulation

L) Cabin design choices mentioned

  • Market cabin types:
    • passenger
    • hospital type
    • freight
  • Door/opening types:
    • single front opening
    • double opposite access
    • lateral corner access
  • Door mechanisms:
    • central double-leaf
    • double telescopic
    • triple-leaf
    • quadruple-leaf
  • Door design must include:
    • space for clear height for doors
    • clear height of passage (wall-mounted or recessed)
    • automatic door mechanisms
    • sensor preventing door closure when a passenger enters

M) Escape-route / fire-safety spatial constraints

  • Consider minimum distances between:
    • ducts / installs and elevator equipment on terraces
  • If machine room < 4 m from duct terminations:
    • ducts must be positioned 50 cm above machine room level
  • If machine room > 4 m from terrace exit:
    • duct height can be 2 m above reserve tank
  • Reserve tank placement:
    • above elevator shaft or machine room, height ~20 cm above
  • Must respect separation relative to stairwell
  • Elevator cannot enter an antechamber of the escape route
  • Stairwell access cannot directly face sensor exits (fire-front risk)
  • Recommendation: define entrance/exit of escape routes and vertical circulation

N) Minimum indispensable service requirements (times + control)

Traffic / service time constraints

  • Sensor system must serve user within:
    • ≤ 30 seconds for commercial buildings
    • ≤ 60 seconds for residential buildings
  • Passenger dwell time limit:
    • typically 60–90 seconds
    • may extend to 150 seconds when multiple stops pick up one person each

Control system types (by building code)

  • lever/crank
  • simple automatic
  • simple automatic with interconnection of hall calls for 2+ cars
  • cumulative selective down for one car
  • cumulative selective up and down for one car

Capacity sizing approach

  • Determine probable maximum demand
  • Study:
    • transport grouping
    • number of sensors / elevators
    • motor power
  • Ordinance 3.407 provides guidelines for determining installation characteristics and number of sensors
  • Designer must choose elevator machine type based on calculations

Elevator calculation methodology (detailed bullet steps)

Overview: “calculation consists of eight states”

  1. Study building situation
  2. Determine building population
  3. Determine five-minute evacuation rate
  4. Determine elevator direction (up/down context)
  5. Compute total/final time
  6. Compute transport capacity
  7. Compute number of sensors (elevators)
  8. Compute motor power

Step 1: Analyze building situation

  • Determine:
    • number of floors to be served
    • covered area
    • whether basements and rooftops are served

Step 2: Determine building population

  • Population = total permanent + transient people accommodated at a time
  • Use building function to determine population via tables
  • Anticipate future population growth to avoid later elevator addition costs
  • Computation concept mentioned:
    • total built area (excluding ground floor and excluding escape means area) ÷ occupancy factor

Step 3: Determine five-minute evacuation rate

  • Based on building function
  • Evacuation rate = coefficient × population (conceptually; exact coefficient from tables)

Step 4: Choose elevator capacity constraints

  • Must serve a minimum number of people per cabin:
    • minimum cabin area 7 m²
  • Add area per additional passenger:
    • +20 m² for each additional person up to 6 people
    • beyond 6: +13 m² per additional person
  • Recommendation: use cabins designed for at least 4 people minimum capacity

Step 5: Compute total/final time (key formula components described)

  • Total/final time (conceptually) =
    • round-trip travel time
      • (sum of door opening/closing time + acceleration time × number of probable stops)
      • passenger entry/exit time
      • extra time for unforeseen detections
  • Round-trip travel time (no stops):
    • travel time = 2 × travel distance / nominal speed
    • travel distance depends on:
      • number of floors served × floor height
  • Door times:
    • normal doors: 6 seconds
    • automatic doors: 4 seconds
  • Acceleration/braking time:
    • derived from nominal speed and a coefficient k depending on travel speed and motor
  • Probable stops:
    • depends on floors served
    • depends on people per trip and cabin stop limits
    • if probable stops exceed max passengers possible, use max passengers limit
  • Passenger entry/exit time:
    • about 4 seconds per passenger
  • Unforeseen extra time:
    • add 10% of previously computed time (only for coordinated grouped elevators, per note)

Step 6: Compute transport capacity

  • Transport capacity =
    • (number of passengers) × (number of trips) × 300 seconds ÷ final time (as expressed/used in the example)

Step 7: Compute number of sensors (elevators)

  • number of sensors =
    • (people to be evacuated in 5 minutes) ÷ transport capacity
  • Example uses computed result to decide sensor count and cabin type

Step 8: Compute motor power

  • Motor power (horsepower) =
    • (unbalanced weight × nominal speed) ÷ (power needed to lift 75 kg by 1 m in 1 s × efficiency)

Worked example (summary of the numbers given)

  • Building: eight-story office building with ground floor + basement + accessible terrace
  • Verified elevator core travel distance within maximum permitted
  • Function: office complex + basement parking
  • Covered area: 255 m²
  • Population:
    • office occupancy factor: 8 m²/person
    • population computed as 254
  • Total evacuation time: 5 minutes
  • Evacuation coefficient:
    • coefficient k = 3% evacuation rate (from Table 3)
    • evacuation in 5 minutes: 39 people
  • Elevator selected:
    • Type 1 cabin: 130 × 110 (units as stated) capacity up to 6 people
  • Total/final time components (as stated):
    • round-trip travel time without stops: 3–6 seconds
    • automatic doors: door open/close time 4 seconds

Original video