Midterm Flashcards
3 areas to look at when inspecting for insulations
Insulation and VB of unfinished spaces
Ventilation of attics and foundation area
Ventilation systems of kitchen, bathroom, and laundry
What do you NOT report as an inspector - 2 Things
Concealed insulation/VB
Indoor air quality
Define Insulation
products that controls heat loss
Define Vapor Barrier
products that restricts vapor diffusion
What is Degree Days?
What does it indicate?
Average temperature for the day is subtracted from 65F
e.g. if temp is 45F then 65-45 = 20F is the degree days
Indicates the demand over a heating season
2 ways moisture is controlled
Ventilation systems
Air/Vapor Barrier
Define Heat
Thermal energy of a body, measured in BTUs
(British Thermal Unit)
Define Temperature
The amount of thermal energy in a body, measured in degrees of F or C
What causes temperature to change
Sensible Heat
The energy used to change the state of substance without changing the temperature is called
Latent Heat
4 ways how heat travels from hot to cold
Conduction
Convection
Radiation
Evaporation
What is Thermal Conductivity (K)
the movement of heat through a homogenous material
number of BTUs per hour that will move through 1ft x 1ft x 1 inch, when the temperature difference from one side to the other is 1F
What is Conductance (C)
the movement of heat through materials that are NOT homogenous or have large voids
number of BTUs per hour that will move through 1ft x 1ft, when the temp difference from one side to the other is 1F
_______ Thermal Conductors slows the heat flow and are good insulators
Low
2 characteristics of good insulators
Hold air still in small pockets
Low density
What is Thermal Resistance?
Good insulation has LOW or HIGH thermal resistance
The inverse of its conductivity or R-value
High
Recommended R-Value for Canada
Attic:
Walls:
Floor and Unheated Space:
R40 - R60
R17
R27
True of False: wind washing is more important than air leakage
False
List three thermal insulators
Cork
Sawdust
Some plastics
List 8 sources of moisture
Drying fire wood inside
Taking shower, doing dishes
Humidifiers
Pets
People sweating/breathing
Doing laundry
Damp soil in crawlspace
Sump pits
Unprotected soil in the house (e.g. earth floor in crawlspace) can generate ___ gallons of water per day
10
Difference between Absolute and Relative humidity
Absolute - actual mount of moisture in the air
Relative - amount of moisture in the air relative to the amount of moisture the fully saturated air could hold; expressed in percentage
As you INCREASE or DECREASE the air temperature, the ABSOLUTE or RELATIVE humidity stays the same, but ABSOLUTE or RELATIVE humidity drops
Increase
Absolute
Relative
Which air holds more moisture - Cold or Warm
Warm air
4 ways the moisture moves
Bulk moisture - leaks
Capillary action - rising damp
Air transported - water vapor in the air moves with air
Vapor diffusion - water vapor moves from high pressure to low pressure without air movement
Describe Stack Effect
Warm air rises and expands, creates high pressure near the top of the house and tries to escape; Low/negative pressure is created at the bottom and draws in outdoor air
True of False: Warm, moist air leaking out does more damage than cold, dry air coming in
True
What is Dew Point Temperature
when humidity is at 100% and condensation starts to form
True of False: Movement of Air is more important than Vapor Diffusion
True
Evidences of high humidity
Condensation on windows
Stuffy air
Staining or mold in bathrooms, or on cold walls, window frames
Odor
Back draft from combustible appliances
5 Ways to solve humidity problem
Produce less moisture
Keep the condensing surface warmer
Stop air leakage
Flush the air out faster
Exhaust warm ,moist air directly outside
Which is more important: Air Barrier or Vapor Barrier
Air Barrier
Advantage of housewraps vs. old building paper
Housewraps have less seams, so has more tight fit. Stops air flow but allows vapor through
2 Advantages of exhausting moisture (ie. exhaust fans)
Sends moisture outside
Lower air pressure inside, less warm air leaking outside, and brings dry air inside.
2 Disadvantages of exhausting moisture (ie. exhaust fans)
Wastes energy by sending heated air out
Lower air pressure can cause backdrafting
2 Concepts of HRV
Removes heat from the warm, exhaust air
Control the location and amount of fresh air drawn into the house
2 Types of house ventilation
Venting of roof and wall systems
Exhausting stale air and supply fresh air into the living spaces
Where does the air barrier have to be located in a warm climate
Exterior wall (or none at all)
6 Components of HRV?
Fan controls
Ducts
Heat exchange
Condensate drain
Defrost mechanism
Flow measure/collars and Balancing Dampers
9 Characteristics of Good Insulation
High R-Value
Durable
Inexpensive
Completely fills cavities
Air Barrier
Vapor Barrier
Moisture and Rot resistance
Non-combustible
Chemically inert
Where do Thermal Bridges occur?
Where the insulation is not continuous, such as studs, top plates, sill plates, etc
4 Types of Insulation forms
Loose-fill/Blown-in
Batts/Blankets
Rigid Board
Foamed-in-place
Name common materials for Loose-fill insulation
Cellulose
Mineral wool
Vermiculite
Sawdust
Perlite
Fiberglass
Name common materials for Batts insulation
Fiberglass
Mineral wool
Name common materials for Rigid Board insulation
Fiberglass
Expanded polystyrene
Extruded polystyrene
Polyurethane
Polyisocyanurate
Name common materials for Foamed in place insulation
Polyurethane
Polyisocyanate
What is the R-value for Extruded Polystyrene board insulation
5.0
R-value of Fiberglass loose fill is ______, and R-value of Cellulose fiber loose fill is _______
3.4
3.5