2. Glazing Design G.K Garden Canadian
Building Digest 55, 1964
• Introduction
• Types of Glazing
• Glazing Material
• Glass Properties
• Frames Used for glazing
3. Types of Glazing
• Single Pane of Glass
• Double glazed
• Gas Filled Window
• Low-e Coating
• Heat Mirror
• Super Window
• Canadian Fiberglas Triple glazed
6. Properties
• Visible transmittance
• Visible Reflectance
• Solar heat gain coefficient
• U / R Values
• Ultraviolet transmittance
• Spectral selectivity
• Fire resistance
• Sound transmission
• Colour
7. Frame
• Wood
– High maintenance
– Moisture problem
• Vinyl
– Low maintenance
– Thick
• Aluminum / Steel
– Strong
– High thermal conductivity
• Fiberglass
– Best but expensive, colour may fade
8. Inert gas fill
• Lower thermal conductivity than air
• Argon, Krypton, Xenon
• Reduce sound transmission
• Sulphur hexafluoride (SF6) , Carbon dioxide
• 0.44 times of velocity of sound in air
9.
10. Coating
• Low-e
• Metal Oxide or
Semiconductor Films
• Blocks heat while
allowing solar energy
to pass through
• Tinting
20. Water Penetration
• Water penetration occurs due to inside-outside
pressure gradients, gravity
• Affected by:
– ‘Time of wetness’: frequency and duration that a window
is wet
– Wind driven rain
– Presence of overhangs
21. Waterproofing
• Determined by glazing method (wet vs dry) and
glazing method
• Wet glazing: gunable sealant installed over a
preformed tape or gasket
• Dry glazing: extruded rubber gaskets as glazing seal
(relies on compression to seal)
22.
23. Moisture Protection
• Need to control forces moving water inward on face
of joints and glazing
• Prevent by having a deterrent to water entry at
wetted face, making air seal at dry side of joint,
which equalizes air pressure in glazing cavity
25. Strategies to Control Moisture
• Limit condensation with low U-value glazing and
supplemental heat to increase glazing surface
temperatures
• Flashings at sill, jambs, and head integrated with
waterproofing at adjacent walls
• Sill and head flashings sloped to exterior for prompt
drainage
26. Design considerations
• Many windows leak at
sash corners and sill to
jamb frame corners
• Miter corners and stiffen
with spline inserts
27. Design considerations
• Vulcanized rubber continuous gaskets and weather-
strips (not very economical)
• Sill flashings with end dams to collect leakage and
drain to exterior (lower quality windows)
28. Moisture Control
• CSA-A440-M “Windows”
– Standard for evaluating and categorizing rain penetration
control performance for windows
– Tests new windows
– Uses historical rainfall and wind records to establish ratings
for municipalities
– Neglects micro climate effects (building form, overhangs,
local terrain) that impact water penetration due to wind
driven rain
Wood- include separate recessed drainage channel in the glazing pocket allows drainage to the weep holes
Steel- narrow profile and therefore shallow glazing pocket, weep covers and foam baffles are critical to air infiltration and water penetration performance
gases are heavier than air and less likely to create convective loops
SF6 has a molar mass of about 146 g/mol
due to the large inertia of a SF6 molecule
some wavelengths of lights, the coating is transparent
where infrared is found, the coating acts like a mirror
reflects energy back
Glass to frame spacing close to 1”
Water shedding surface: surface of assemblies, interfaces, and details that deflect and/or drain vast majority of exterior moisture impacting on facade
Factors: moisture, UV, temperature, pressure, wind, seismic events, etc.
