PROJECT: VENT-SLAB DETAIL
LIVING SHANGRI LA BUILDING
PORJECT TEAM
Design Architect: James KM Cheng Architects Project Architects: Hariri Pontarini Architects Young + Wright / IBI Group Architects ERA Architects Inc. Landscape Architect:
Phillips Farevaag Smallenberg Inc.
Developer:
Westbank & Peterson Group
Electrical Engineer:
Nemetz (S/A) & Associates Ltd.
Structural Engineer:
Jones Kwong Kishi, Adjeleian Allen Rubeli Ltd.
Real Estate Agent:
Rennie Marketing Systems
Formwork supplier: Doka Industrie GmbH Hardrock Forming Company Concrete Supplier: Innocon Inc. Toronto Redi-Mix Ltd. Ontario Redimix Ltd Dufferin Concrete Steel Supplier:
Salit Steel Ltd.
Shoring Contractor:
Anchor Shoring & Caissons Ltd.
Wind Surveyor:
RWDI
Demolition Company:
Greenspoon Specialty Contracting
Excavation Company:
Aro Excavating Ltd.
Traffic Consultant:
BA Group
Consultantcy: LMDG Building Code Consultants Brook Van Dalen & Associates John W. Gunn Consultants Inc. Terraprobe Ltd. Mortgage Bank:
Caisse de dépôt et placement du Québec
address:
180 University Ave
city:
Toronto, ON
country:
Canada
year completed:
2012
gross floor area:
81,192.38 m²
architectural height:
214.50 m
top floor:
207.30 m
floors above ground:
66
floors below ground:
5
hotel: Shangri-La Worldwide 1-17 Floor 222 Units residences: Living Shangri-La 18-49 287 Residences estates: 50-66 83 Private Estates (incl. 2 Penthouses)
LIVING SHANGRI LA BUILDING
Curtain walls are popular non-structural systems used for building envelopes. Often made of lightweight materials, the curtain wall is non-load bearing and transfers any horizontal loads directly to the structure through connections at the floor slabs. The curtain wall system found on the Living Shangri La building is fairly straight-forwarded with the introduction of smaller design details that display a creative solution to structural and mechanical needs.
CONTEXT
The Living Shangri-La project found neatly situated on University Avenue between Richmond St. W. and Adelaide St. W. adds a distinguishing element to Toronto’s skyline. At 66-storeys tall, the building is cladded in a beautiful glass façade with subtle details that reflect the elegance of the Shangri La brand of hotels. Nestled in between the Entertainment District and Fashion District, this iconic tower is home to luxurious hotel rooms, residences, private estates, and penthouse homes. The ability to encapsulate all these uses within a uniform building envelope is both challenging and innovative. Of the many interesting details found throughout the envelope, the detail being highlighted in this report is the in-slab vent that is seamlessly integrated into the curtain wall system.
LIVING SHANGRI LA BUILDING
CONTEXT
mechanical vents
19mm wood sil 13mm gypsum board
15.9mm gypsum board (acoustic) spandrel glazing with insulated back panel fire stopping & smoke seal
continuous heating pipe 230mm concrete slab eccoduct in-slab ducting
wall vent 50mm srpay poly urethane insulation curtain wall system joint components 16mm ply blocking
mechanical duct 41mm steel studs at 600mm o/c
painted mdf valance soffit window glazing
13mm gypsum board
LIVING SHANGRI LA BUILDING
curtain wall system joint components
DETAIL COMPONENTS
window glazing
LIVING SHANGRI LA BUILDING
HEAT
HEAT LOSS ANALYSIS
fire stopping and smoke seal
continuous heating pipe concrete slab spandrel insulation
The greatest challenge to envelope design is heat leakage through conductive elements such as window mullions, and slab edges. To minimize the thermal bridging between these elements, the most effective method is to spec high quality glass panes and apply thermal breaks in the mullion so that the mullion unit does not conduct from the inside to the outside. Since the Shangri-La hotel is located in Toronto, ON where there is a difference of 40 degrees Celsius between interior design temperature and exterior design temperature, it is interesting to review how they’ve minimize the effects of thermal heat transfer. The building predominantly utilizes a curtain wall system with the exception of some lower level podium masonry elements. As a result, energy consumption in heating and cooling during different times of the year is critical. Concrete floor slabs are typical in this type of construction. One of the primary thermal concerns to concrete slabs is thermal bridging to the exterior. In this specific detail, we notice that the vent/ soffit module is found within the concrete floor slab and adds an additional conducting path to the exterior that is unique. To address this issue, the vent is insulated with 50 mm spray poly urethane insulation and sealed with caulking as it meets the concrete slab. By applying the 50 mm spray poly urethane, it drastically minimizes the heat transfer and thermal bridging effect. 16 mm ply blocking is continuous between the spray poly urethane and the gypsum board finish on the underside of the slab. Air and vapour barriers complete the system by preventing any possible short circuiting through vapour diffusion or air leakages.
spray poly-urethane foam
As spandrel glazing doesn’t provide significant insulation, the possibility of thermal bridging through the concrete slab edge is high. Thus the system includes an insulated back panel between the spandrel glazing and the adjacent concrete slab edge. Firestopping and smoke seals are found between the insulated back spandrel panel and the concrete slab edge. Although not a vital component to insulating the slab edge, it inevitably reduces heat transfer between the slab edge and the spandrel panel system. Performance Strengths: - The slab edge being the largest potential thermal bridge is well insulated - Heating under the window will prevent convection currents Performance Weaknesses: - Although insulated near the envelope exterior, the aluminum duct can act as a conductor to bridge the concrete to the outside causing cold spots on the floor - Being a curtain wall, the walls generally don’t provide a significant amount of thermal resistance
Curtain walls are inherently designed to resist water penetration due the low permeability of glass which functions both as a rain screen and a vapour barrier. As the vast majority of the surface area of a curtain wall comprises of glazing, the points that need the most attention with respect to water leakage are the joints and mullions. The seams and edge conditions where the curtain wall glazing meets the mullions need to be sufficiently sealed. As a second layer of defence, a vapour barrier is placed inside the mullion to catch any unwanted moisture that may have penetrated through the seal. The water is collected along this membrane and drained back to the exterior through the weep holes located at the bottom of the mullions.
Over time, expansion and contraction as a direct result of weather can cause deterioration over time and leave the system susceptible to water penetration. Deterioration of the seals and joints can cause a decrease in performance, regular maintenance will ensure the caulking and seals are functional and minimize any water penetration into the curtain wall system. Performance Strengths: - Since the curtain wall surface area is primarily glazing, vapour diffusion is largely reduced - Continuous vapour barrier along the vertical length of the mullion. - Outwards sloping wall vent prevents water collection in ducts. Performance Weaknesses: - A disconnect in vapour barrier at the bottom of the spandrel pannel to the top of the window assembly below adds a potential infiltration point.
WATER
Another potential point of entry through the curtain wall system is through the wall vent. Hydrostatic pressure could potentially draw water through the mesh and into the duct. To prevent this the mouth of the vent is sloped downwards towards the exterior to drain out any water.
vapour barrier
glazing panels
weep holes
wall vent
vapour barrier
LIVING SHANGRI LA BUILDING
WATER LEAKAGE ANALYSIS
LIVING SHANGRI LA BUILDING
AIR
AIR LEAKAGE ANALYSIS
air barrier
window joints glazing panels
To prevent air infiltration, a continuous air barrier must be in place so that air currents can’t short circuit insulation or vapour barriers. In a curtain wall system, the primary vulnerabilities are at the edges of the glazing panels. Specifically, the window joints, mullions and weep holes must be sufficiently sealed so that air can’t penetrate the envelope. This is especially true since this curtain wall contains openable windows just above the spandrels. It is unclear in the detail drawings for the Shangri-La hotel if there is a continuous air barrier, but they suggest that the vapour barrier doubles as an air barrier. However, the discontinuity of the air barrier with the glazing panels underneath the wall vent could compromise the system. The particular placement of the wall vent across the façade of the building also adds a potential air leakage point potentially drawing up water vapour into the ductwork. This is mitigated by the placement of a backdraft damper at the mouth of the vent. Proper maintenance is important with regards to air leakage as the seals and caulking could deteriorate over time through temperature swings. Thus reducing the overall effectiveness of the envelope system.
weep holes
Performance Strengths: - Wall system is sealed above the spandrel glazing. - Wall vent mitigates back draft
backdraft damper
air barrier
Performance Weaknesses: - Potential discontinuity in air barrier system underneath wall vent may compromise air-tightness
An interesting element to the vent and soffit design is that the mechanism travels through the concrete floor slab. This is a product of ECCODUCT, a company specializing in creating systems that are encased (in the case of the Living Shangri La building, in concrete). The soffit exits the floor slab and is connected to a Metal Plenum that is insulated by 50 mm spray poly urethane foam to prevent any thermal bridging. Performance Strengths: - Having the structural steel component positioned around the heating pipe could potentially reduce thermal bridging through the system.
aluminum curtain wall mullion
curtain wall anchor
STRUCTURE
Curtain wall systems function as a non-structural component of a building. It bears no structural load and only carries its own dead load. As a building envelope, it can be lightweight and versatile. In the case of the Living Shangri La building, the curtain walls are designed to transfer any horizontal wind loads it receives directly into the structural floor slab that it is connected to. The mullion system is fairly complex and includes an aluminum curtain wall sill mullion, a curtain wall anchor poured into the concrete slab, and various metal studs. These components ensure that the curtain wall is secured and fastened to the floor slab.
LIVING SHANGRI LA BUILDING
STRUCTURAL ANALYSIS
LIVING SHANGRI LA BUILDING
MODEL PHOTOS
LIVING SHANGRI LA BUILDING
MODEL PHOTOS
LIVING SHANGRI LA BUILDING
TECHNICAL DRAWINGS
SKY BRIDGE Straddling a path that links two ski runs (site map), Sky Bridge is a timber structure that offers itself as a shelter and viewing platform for Ski Rangers and recreational visitors alike. The bridge or pier slides through a pine stand and offers up 3 tiers of experience and views to the valley below: Main Platform; Secondary Viewing Deck; Lower Access stairs/ramp. The structure is composed of solid hewn, light wood frame and heavy timber. A light wood frame deck is suspended between 2 heavy timber trusses that project horizontally 30 meters from the hillside. Cross-tensioning rods provide lateral stability to the pier. At the end of the pier, a heated volume (100 sq. ft) is nested beneath a secondary viewing platform. A beam extends across the width of the structure, receiving primary loads from the three trusses and a secondary set of loads from the stairs and raised viewing platform. 3 timber columns transfer their load to concrete caissons embedded in the hillside. Two smaller concrete bearing piers take the load at the entry to the pier entry and at the lower level stairs. Articulated steel joints connect the muscular, timber structure revealing pinned and fixed connections. A lightweight skin of timber slats runs diagonally across major structural members (truss and post/beam) acting as tension and compression members and offering degrees of enclosure and view. Après-ski on the Sky Bridge, Ranger at the edge, Poised for a breathtaking departure, A ramp to a path to the hills below.
Diagonal Sheathing on Truss
Long Span Timber Truss Diagonal Frame/Truss
Timber Compression & Steel Tension Members for lateral stability
ASSEMBLY DIAGRAM
Conditioned Space
Timber Deck Supported by Secondary Beams & Joist
Compression Timber Member Resisting Lateral Force Cantilever Timber Beam Supporting Stair Landing
Sheathing on Timber Truss Frame
Deep Timber Beam Load Bearing Timber Columns
GRAVITY LOAD DIAGRAM
terminates in grounded footings
LATERAL LOAD DIAGRAM
terminates in grounded footings
5319 800
1900
1100
3000
1900
Level 2 - Observation (+12.45m)
Column Beyond
EAST ELEVATION Bridge Truss 1a 1:100
View Opening
Level 1 - Bridge (+09.00m)
Column Beyond
Grade - Lowest Point (+/- 00.00m)
Stair Below
38 17
Open to Below
Brace Above Enclosed Space (Below)
1645
45
41
8 Risers @ 150 mm
8600 Bench (Below)
LEVEL 2 PLAN Observation 1:100
Bridge (Below)
Lowered Beams (Joist Bearing on Top)
61
40
00
69
25 @ ? Ris 15 ers 0m m
(TY 30 85 ME PIC MB AL ER VER SP TIC AC INGAL )
18
94
LEVEL 1.5 PLAN
52
71
27950 1025
Open to Below
15 @ Rise 15 rs 0m m
1:100
10 NUMBER
2150
10 NUMBER
(TYPICAL)
2344
4000
Enclosed Space (Glass Box)
25800
10750
(CANTILEVER) Lowered Beams (Joist Bearing on Top)
LEVEL 1 PLAN
Bridge / Porch / Box / Outlook 1:100
Landing
40
00
Truss(es) Joist(s) Secondary Beam(s) Primary Beam Primary Column(s) Primary Beam 10 NUMBER
27950
10 NUMBER
Secondary Beam - Mid-Height Stair Support / Truss Brace
10 NUMBER
Secondary Beam - Stair Support / Truss Brace Cantilever Enclosed Space (Above)
Secondary Column
4000
Secondary Beam - Outlook Support Cantilever
10 NUMBER
10 NUMBER
10 NUMBER
Stair Stringer
Stair Riser Decking
25800 Truss Brace
LEVEL 0 PLAN Understory
1:100
Level 2 - Observation (+12.45m)
1100
Level 1.5 - Landing (+11.25m)
800
Level 1 - Bridge (+09.00m)
Enclosed Space
Column Beyond
Grade - Lowest Point (+/- 00.00m)
WEST ELEVATION
Bridge Truss 1b 1:100
Level 2 - Observation (+12.45m)
Level 1.5 - Landing (+11.25m)
1100
Level 1 - Bridge (+09.00m)
Column (Beyond)
Column (Beyond)
Grade - Lowest Point (+/- 00.00m)
Cantilevered Stair Stringer
Grade - Lowest Point (+/- 00.00m)
WEST ELEVATION
Stair Truss 1:100
5316
Truss Brace
Level 2 - Observation (+12.45m)
1900
Level 2 - Observation (+12.45m)
Level 1.5 - Landing (+11.25m)
Level 1.5 - Landing (+11.25m)
1900
Enclosed Space (Beyond)
Level 1 - Bridge (+09.00m)
Level 1 - Bridge (+09.00m)
Enclosed Space
Column (Beyond)
Column (Beyond)
Column (Beyond)
Grade - Lowest Point (+/- 00.00m)
SOUTH ELEVATION Face Truss / Outlook
1:100
NORTH ELEVATION
Braced Frame 1:100
At the summit of Blue Mountain, a timber sphinx stretches out, tucked in a pine stand, hovering in a white sea.