Unit 51 Flashcards
What is energy auditing?
A comprehensive review of a building’s current energy use and efficiency.
Who conducts energy audits?
Carpenters who have been certified as energy auditors.
What are the areas in which energy auditing requires training?
All types of mechanical and electrical systems and equipment, and the use of various instruments
What are the energy-efficiency benefits of performing an energy audit?
Reduced utility costs, improved occupant saftey and comfort, green building recognition
Name 10 tools used in energy auditing (fig 51-3)
auditing software, power qualityi monitors, airquality meter, combustible gas meter, ultrasonic leak detector, thermal imager, clamp meter, laser distance meter, infrared thermometer, digital multimeter
Name four examples of fenestrations.
windows, doors, outdoor lights, doorbells, bathroom or exhaust fan vents, and chimney flues.
What is a fenestration?
an intentional opening in a building envelope
What are signs of water infiltration? (Name up to 4)
stained walls or foundations, bubbling or peeling drywall or plaster, visible mould or mildew, a musty smell
What is a building envelope?
A continuous thermal and airboundary separating the conditioned space from any unconditioned space or from teh outside.
What is a thermal imager?
A device that detects heat patterns in the infrared wavelength spectrum without making direct contact with the targeted area.
What is a thermal imager used for?
To detect the temperature differences that can indicate air leaks or moisture intrusion.
What is a pressure gauge used to calculate?
the amount of air leakage into a building, after a leak has been detected by a blower door test
A blower door creates a pressure difference of what in relation to the outside?
50 Pa
What are the 3 components of a blower door test?
A variable-speed calibrated fan, a door panel system, and instruments to measure fain airflow and building pressure.
What is pressure differential?
the difference between the pressures on either side of a barrier
What conditions must be met before conducting the blower door test?
Windows and exterior doors must be closed; combustion devices must be turned off;
Fireplaces must be clean of ashes;
house thermostats must be off;
all air movers must be off;
window air conditioner vents to the outside must be closed;
interior room doors must be open and secured in the open position;
duct registers must be open;
return air filters must be removed if they are dirty.
What is building science?
The study of interaction between a building (including its HVAC, mechanical, and electrical systems), its inhabitants, and the surrounding environment.
What is heat transfer?
The flow of heat from warm to cold areas.
How can heat flow be prevented?
By using certain construction materials for the exterior walls of buildings (wood, brick, concrete and masonry) and thermal insulation.
What does “thermal” mean in “thermal insulation”?
Materials that have high heat flow resistance.
What is conduction?
The movement of heat through solid or liquid.
Which transfers heat more quickly, conductors or insulators?
Conductors
What is convection?
The movement of heat through the circulatory motion of air or liquid.
Is air heated in a furnace and carried to different areas of a house an example of conduction, convection, or insulation?
convection
What do the initials (k), (C), (U), and (R) stand for?
(k): conductivity
(C): Conductance
(U): Transmittance
(R): Resistance
What unit is heat measured in?
Btu - British thermal unit
Do the best materials for insulation have a low or high k- or C- factor?
low
What is the k-factor?
k-factor = conductivity
Measures the amount of heat that travels through homogenous material.
Expressed as a decimal measurement of how many Btu per hour (Btu/hr) pass through 1 sq ft of material that is 1” thick and has a temp difference of 1*F.
What are 3 examples of homogenous materials?
Concrete, wood, and polyurethane foam insulation
What is the R-value?
R-value: Resistance Value
the ability of a material to resist heat flow
Metric equivalent of this is RSI, the R-value expressed in metric units.
What has a higher k-factor, a concrete wall foundation or wood stud?
concrete wall foundation
What is the kind condensation called that can occur inside a wall?
Concealed condensation (as opposed to surface condensation)
Which three effects may result in a pressure difference between the inside and outside of a building?
wind effect, stack effect, and/or combustion-and-ventilation effect (see p. 561 for explanations).
Where are soffit vents located?
Beneath a roof cornice
Where are coninuous ridge vents located?
along the ridge of a roof.
