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
What creates the most constant pressure on an annual bases?
The stack efect
When will capillary action be prevented?
when the pore size is over 3mm or 1/8th
Where must a vapour barrier be installed?
on the warm side of the insulation
what is the purpose of a vapour barrier?
to reduce water vapour diffusion through the interior finish into the building envelope
what is the difference between a vapour barrier and an air barrier
Vapour diffusion is the process of moisture passing through breathable building materials, like drywall and insulation. Vapour barriers are there to prevent that from happening. Air leakage is due to air pressure differences between indoors and out, which forces air through any holes in your air barrier.
What is the time listed with wall sheathing papers?
rated 30 minutes or 60 minutes. time listed is the time it takes for water to pass through the paper if one side is continually in contact with bulk water during a “boat test”
Where is Sheathing paper and house wrap not intended for?
horizontal or low slope surfaces
Where are flashing materials needed?
joints between exterior finishes, the tops of windows and doors, joints between wall and roof surfaces, at the top of parapet walls
what is used with rain screen systems behind the cladding to create a capillary break?
batten or drainage mats
What absorbs sound?
a soft surface
What are the reflected sound waves referred to as?
Reverberated sound
A material with a high STC number is what?
very good a resisting sound transfer
walls of a doctors office should have a STC rating of?
45 or higher
how much louder is it for every 3 decibels increased?
double the volume of sound
What are 3 ways to increase the STC rating in a wall?
double wall construction, staggered studs, resilient channels
What is smart framing?
rafters, studs, and joists line up vertically eliminating a second top plate. windows and doors line up with on centre layout
What are 2 types of trusses that can prevent Ice dams?
High heel truss, dropped chord truss
Loose filled insulation can be installed in vaulted ceilings if the roof slope is not greater than?
4.5 in 12
The HRV system will recover up to what % of the heat in the exhausted air?
80%
What is Net-zero?
a building with zero net energy consumption and zero carbon emissions annually
What are low e coatings?
allows ultraviolet rays from the sun to pass but reflects the inside infrared (radiant) rays back into the building
What are acoustical sealants designed to do?
must maintain their flexibility through its life. seal joints to prevent sound from leaking through
What prevents pressure differentials?
Air barriers
What is the most effective type of ventilation system?
Balanced system that supplies and and exhausts air
Where are carbon monoxide detectors required?
in dwelling units that have a fuel burning appliance or an attached storage garage
Heat transfer by a gas or a liquid is know as?
Convection
Heat transfer through a solid object is know as?
Conduction
What is the best insulator?
- concrete
- steel
- wood
- insulation
wood
Spray foam is what kind of product?
Polyurethane product
Vent in attic space with a roof slope greater than 1-6 must be at least?
1/300
Acoustical materials used for controlling sound transmission are designed to provide?
reflection, absorption, or transfer of sound
The methods used in energy efficient framing in 2X6 from 2X4 walls?
Dry wall clips, double stud wall framing
