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23 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is building science? |
A mix of physics, material science, meteorology, construction technology, physiology, and engineering analysis and design |
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Sustainability |
• conserve water • conserve energy • conserve materials • control solid waste • encourage sustainable communities
must design durable and energy efficient buildings that use materials responsibly |
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Building Envelope |
barrier that separates the inside from the outside. includes roofs, decks, walls, foundation system, doors, windows |
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functions of the building envelope |
• control rain penetration • control condensation • control air flow • control water vapour flow • control interior environment • control space conditioning requirements (energy) • control light, solar and other radiation • control noise • control fire and smoke • provide security • provide privacy and views • be durable • be aesthetically pleasing and marketable • be constructible • be maintainable • transfer structural loads |
16 functions - 9 "control" functions |
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outdoor environment |
• air temperature range • precipitation • humidity range • hours of sunshine • wind |
5 parts |
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how does climate differ from weather? |
climate is statistical, weather is a specific period of time |
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3 climate zones of BC |
• lower mainland, southwest coast, Vancouver island (wet coast, temperate rainforest) • southern BC interior (hot/dry summer, cold/snowy winter) • northern BC (even colder temperatures) |
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indoor environment and human comfort |
a balance of air temperature, radiant temperature, and humidity |
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how is indoor humidity produced? |
bathing, breathing, cooking, watering plants, indoor spa, wet basements, drying laundry indoor |
7 |
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leaky buildings result in: |
• material damage • potential health hazards • repair and restoration • economic impact |
4 |
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problems of removing and replacing a building envelope: |
• wastes valuable natural resources • increases carbon production |
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why did recent failures occur? |
• adding insulation creates a colder wall, reducing drying ability • vapour barriers prevent drying to inside • less air leakage increases indoor humidity and prevents air from drying wet materials • poor design and construction of critical details while building form became more complex and exposed • use of new materials whose characteristics where not fully understood • stylistic changes resulting in reduced roof overhangs and more decks • building owners/developers not willing to pay for more expensive but durable options • lack of proper maintenance after building is built |
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why do older buildings seem more durable? |
• bigger roof overhangs which offer more rain protection • less airtight and had less insulation resulting in increased drying through wall spaces • window construction allowed for more overhang protection |
3 reasons |
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problems with older buildings: |
• use more energy resources (no longer an affordable luxury) since they leak air out of the envelope (drafty and cold) |
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building science reasons for the performance of building types |
• large overhangs and cornices protect upper wall surfaces • heat loss into the attic keeps it warm which lowers the relative humidity of the ventilation air entering and keeps the framing warm and dry • projecting window sills help shed water • combustion equipment draws outside air into the building which lowers the indoor relative humidity levels and helps dry the envelope • heat loss through and uninsulated wall keeps the sheathing above dew point temperature • vapour barriers don't allow drying to the inside when indoor RH levels are low and when sunlight drives vapour to flow inside • drying to the outside occurs through solid wood sheathing and cladding by diffusion |
7 reasons |
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wood frame damage |
rot caused by fungus (mould, white rot and brown rot) |
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wood frame damage |
rot caused by fungus (mould, white rot and brown rot) • fungal growth increases wood moisture content which encourages even more rot • heartwood is more decay resistant than sapwood (there is more sapwood in younger trees) |
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fungal growth |
flourishes in: • mild temperatures • moisture content in wood > 20% • oxygen present and a good source
feeds on: • cellulose, lignin • wood, paper |
flourishes in ..? feeds on ..? |
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metal damage |
structural steel beams and connectors used in conjunction with wood framing and steel stud framing are damaged due to: • corrosion • fastener failure |
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masonry/concrete damage |
• freeze/thaw • staining – porous materials: water can be sucked into material by capillary action causes spalling and damage if the water freezes and expands – reinforced concrete: if water penetrates concrete, steel reinforcing can rust, swell and cause concrete to spall and break apart. salt in water increases corrosion |
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masonry and mortar |
porous material: • will absorb moisture if allowed to pool • not to be used horizontally or in sloped conditions (only vertical applications) |
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types of damage to masonry and mortar |
• staining • algae growth • infiltration of water into wall • freeze/thaw spalling • problem efflorescence |
5 types of damage |
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building envelope management is required to: |
• create human comfort • maintain human health • public good • save money on energy use • save energy resources • save money on repair and replacement • extend material durability |
7 requirements |
