CSLB C20 TRADE TOUGHER
COMPREHENSIVE EXAM QUESTIONS AND
SOLUTIONS STUDY GUIDE
●● Low boy furnace:
Answer: Similar to Upflow except the furnace is shorter so it can fit in
basement with low ceilings.
●● Down flow furnace:
Answer: Furnace goes into the attic and pushes air down through vents.
Ductwork may be in a concrete slab floor or a crawl space under the
house.
●● Horizontal Furnace
Answer: Furnace is positioned on its side instead of vertically. These
furnaces can be installed in crawl spaces, attics or basements.
●● Multipurpose furnace
Answer: A furnace that can be configured for upflow, downflow, or
horizontal installation.
●● BTU (British Thermal Unit)
, Answer: The unit of heat needed to raise one pound of water one degree
Fahrenheit. The BTU is used to rate the capacity of heating and air-
conditioning units.
Air conditioning is measured in Tons of refrigeration (RT) A Ton of
refrigeration is approximately 12,000 BTU/h
●● thermal transmittance ( U value)
Answer: Measure how quickly heat-loss occurs through different
materials.
Example: Doors, insulation, windows ect.
●● R-Value:
Answer: Measures resistance to heat flow so the higher the R-value the
better it insulated a building.
●● Calculating U-value:
Answer: Involves adding the resistance of all insulating materials and
then dividing one by that number.
●● What is thermal lag?
Answer: Is the delay of heat transmitted through a wall.
COMPREHENSIVE EXAM QUESTIONS AND
SOLUTIONS STUDY GUIDE
●● Low boy furnace:
Answer: Similar to Upflow except the furnace is shorter so it can fit in
basement with low ceilings.
●● Down flow furnace:
Answer: Furnace goes into the attic and pushes air down through vents.
Ductwork may be in a concrete slab floor or a crawl space under the
house.
●● Horizontal Furnace
Answer: Furnace is positioned on its side instead of vertically. These
furnaces can be installed in crawl spaces, attics or basements.
●● Multipurpose furnace
Answer: A furnace that can be configured for upflow, downflow, or
horizontal installation.
●● BTU (British Thermal Unit)
, Answer: The unit of heat needed to raise one pound of water one degree
Fahrenheit. The BTU is used to rate the capacity of heating and air-
conditioning units.
Air conditioning is measured in Tons of refrigeration (RT) A Ton of
refrigeration is approximately 12,000 BTU/h
●● thermal transmittance ( U value)
Answer: Measure how quickly heat-loss occurs through different
materials.
Example: Doors, insulation, windows ect.
●● R-Value:
Answer: Measures resistance to heat flow so the higher the R-value the
better it insulated a building.
●● Calculating U-value:
Answer: Involves adding the resistance of all insulating materials and
then dividing one by that number.
●● What is thermal lag?
Answer: Is the delay of heat transmitted through a wall.
