HVAC 6010 - Heat Gains and Losses (Chp 1)

Question 1

External heat gains in a building are caused by:

A) Infiltration and heat gain from people and lighting
B) Exhausted air, radiation through windows, lighting
C) Infiltration, conduction, ventilation, and solar radiation
D) Hot water tanks, boilers, and appliances
E) Motors, boilers, and other mechanical equipment

Answer 1

C) Infiltration, conduction, ventilation, and solar radiation

Question 2

Which of the following methods can be used to estimate the ventilation load on a building?

A) Conversion method
B) The "U" factor method
C) Crack method
D) Conduction method
E) Ventilation method

Answer 2

C) Crack method

Question 3

Thermal conductance (C) may be defined as the:

A) Thermal heat flow by conduction only through a single uniform type of material (W/mK)
B) Thermal transmission through a unit area of a particular body where the difference between temperatures on either side of the body is unity (W/m2K)
C) Quantity of heat flow in unit time (Q or W)
D) Reciprocal of thermal conductance (mK/W)
E) Thermal heat flow through a unit of a non-uniform composite material when a unit average temperature difference is established between the surfaces (W/m2K)

Answer 3

E) Thermal heat flow through a unit of a non-uniform composite material when a unit average temperature difference is established between the surfaces (W/m2K)

Question 4

Heat load from the people in a room is mostly affected by:

A) The number of people
B) The activity of the people
C) None of the above
D) Smoking
E) The size of the people

Answer 4

B) The activity of the people

Question 5

One of the factors used to “determine the ventilation” rate in a building is the:

A) Solar load on the building
B) Type of electrical equipment used in the building
C) Cubic metre per hour (CFM) requirements per person
D) Activity in the building
E) Type of insulation used in the building

Answer 5

C) Cubic metre per hour (CFM) requirements per person

Question 6

The resistance to heat flow through walls, floors, and windows is known as:

A) U-factor
B) Ventilation
C) Total thermal resistance
D) Infiltration
E) Reduced solar load

Answer 6

A) U-factor

Question 7

Electric motors give off _____ while running.

A) Solar heat
B) Sensible heat
C) Latent and sensible heat
D) No heat to the atmosphere
E) Latent heat

Answer 7

B) Sensible heat

Question 8

Heat lost from a building is:

A) Not affected by the density of the air
B) Affected by wind velocity
C) Is not affected by wind velocity
D) Dependent on the shape of the openings in a building
E) Independent from the outside air temperature

Answer 8

B) Affected by wind velocity

Question 9

Rankine and Kelvin are absolute temperature scales whose starting point is absolute zero (the lowest temperature possible). They are related to Farenheit and Celsius temperature scales by:

A) C =Rankine - 460 , F = Kelvin - 273
B) C = Rankine - 273, F = Kelvin - 460
C) C = Kelvin - 460, F = Rankine + 273
D) C = Kelvin - 273, F = Rankine - 460
E) C = Kelvin - 460, F = Rankine - 273

Answer 9

D) C = Kelvin - 273, F = Rankine - 460

Question 10

The amount of heat lost by a building due to conduction, convection, and infiltration is directly affected by:

A) Geographic location of the building
B) The type of activity in the building
C) The velocity of the wind
D) The type of heating system used in the building
E) Outside air temperature

Answer 10

C) The velocity of the wind

Question 11

Rankine and Kelvin are absolute temperature scales whose starting point is absolute zero (the lowest temperature possible). Fahrenheit = Rankine – 460 . (zero R = 460 F, or, Freezing point of water = + 32 degrees Fahrenheit = + 492 Rankine) If Celsius = Kelvin -273, zero K = 273 C, then boiling point of water =

A) 560 K and 485 R
B) 100 K and 212 R
C) 373 K and 672 R
D) 273 K and 460 R
E) 173 K and 248 R

Answer 11

C) 373 K and 672 R