J2-J3 Building Science Flashcards
What is the Stack effect?
When hot air rises and escapes through the upper floor-level opening of a building, cold air is drawn into the basement or lower floors. (Large Convection Current)
What is the Flue effect?
When a hot water tank or a furnace (NAFFVA) is venting out air, negative air pressure is created inside the building.
What is the Wind effect?
also known as “wind-washing” wind causes high pressure on the windward side pushing wind through and cracks. also drawing warm air out of the building cause by negative air pressure on the leeward side of the building.
What is NPP?
Neutral pressure plane is an imaginary line where the pressure difference between inside and outside is zero
What are the three types of Vent systems?
Exhaust systems, Supply systems, balanced systems
What is the Dew Point?
The point at witch water vapour condenses into liquid water
Which method of posture movement causes the most moisture to enter a wall cavity?
Airflow
Which can hold the most moisture at the same humidity, cold air or warm air?
Warm Air
What are The Four D’s of controlling moisture?
Deflection, Drainage, Drying, Durable Materials
What are End Dams?
capped ends off flashing to prevent the wind from blowing water behind the cladding
What is minimum projection for drip flashing?
1 inch beyond face of exterior finish
What does a Pressure-equalized rain screen do?
neutralizes the effect of the wind on the face of the cladding by creating an equal pressure on both sides of the cladding
What are durable materials?
Materials that can go through wetting a drying cycles and be exposed to ultraviolet radiation (UV) without breaking down or deteriorating
What is the type of heat transfer that a thermal break prevents?
Conduction
RSI1 is equal to what R value?
R5.7
RSI3.5 is equal to what R value?
R20
What is classified as a thermal bridge?
a stud in a wall
What is Wind washing?
wind/air movement through insulation decreasing the insulating value
What has a greater effect on thermal efficiency?
Air Tightness
What occurs to water with capillary action?
Water is lifted against the force of gravity through narrow pores
Moisture intrusion by air movement moves over ___ times more moisture than diffusion.
100 times