Chapter 1 Heat Gains & Losses Flashcards
1.Thermal conductivity (λ) is the:
A. Thermal heat flow (transmission) through unit areas of a wall, door, window, etc., for every degree temperature difference between the air/fluid inside and the air/fluid outside. (W/m²K or W/m²°C) (Btu/hr/ft²R or Btu/hr/ft²°F)
B. Quantity of heat flow from all mechanisms, in unit time, under the conditions prevailing at that time (Q or W)
C. Thermal heat flow, by conduction only, through a unit area of a single uniform type of material (W/m°C) (Btu/hr/ft²°F).
D. Thermal heat flow through a unit area of a non-uniform, composite material when a unit average temperature difference is established between the surfaces (W/m²°C) (Btu/hr/ft²°F)
E. Reciprocal of thermal conductance, it is the value of a given material’s ability to resist heat transfer or flow (m²°C/W) (ft²°F/Btu/hr
C. Thermal heat flow, by conduction only, through a unit area of a single uniform type of material (W/m°C) (Btu/hr/ft²°F).
- Thermal transmission or rate of heat flow is the:
A. Thermal heat flow (transmission) through unit areas of a wall, door, window, etc., for every degree temperature difference between the air/fluid inside and the air/fluid outside. (W/m²K or W/m²°C) (Btu/hr/ft²R or Btu/hr/ft²°F)
B. Quantity of heat flow from all mechanisms, in unit time, under the conditions prevailing at that time (Q or W)
C. Thermal heat flow, by conduction only, through a unit area of a single uniform type of material (W/m°C) (Btu/hr/ft²°F)
D. Thermal heat flow through a unit area of a non-uniform, composite material when a unit average temperature difference is established between the surfaces (W/m²°C) (Btu/hr/ft²°F)
E. Reciprocal of thermal conductance, it is the value of a given material’s ability to resist heat transfer or flow (m²°C/W) (ft²°F/Btu/hr)
B. Quantity of heat flow from all mechanisms, in unit time, under the conditions prevailing at that time (Q or W)
- Thermal conductance (C) is the:
A. Thermal heat flow (transmission) through unit areas of a wall, door, window, etc., for every degree temperature difference between the air/fluid inside and the air/fluid outside. (W/m²K or W/m²°C) (Btu/hr/ft²R or Btu/hr/ft²°F)
B. Quantity of heat flow from all mechanisms, in unit time, under the conditions prevailing at that time (Q or W)
C. Thermal heat flow, by conduction only, through a unit area of a single uniform type of material (W/m°C) (Btu/hr/ft²°F)
D. Thermal heat flow through a unit area of a non-uniform, composite material when a unit average temperature difference is established between the surfaces (W/m²°C) (Btu/hr/ft²°F)
E. Reciprocal of thermal conductance, it is the value of a given material’s ability to resist heat transfer or flow (m²°C/W) (ft²°F/Btu/hr)
D. Thermal heat flow through a unit area of a non-uniform, composite material when a unit average temperature difference is established between the surfaces (W/m²°C) (Btu/hr/ft²°F)
- Conduction heat gains are based on the assumption that the temperature of the outer surface of the building is the same as the:
A. Coldest winter temperature
B. Warmest summer temperature
C. Average of winter and summer temperatures
D. Indoor design temperature
E. Outdoor design condition
E. Outdoor design condition
- Heat passes through building walls, ceilings, and floors from the warmer inner surfaces to the cooler outer surfaces by:
A. Construction
B. Conservation
C. Occupation
D. Insulation
E. Conduction
E. Conduction
- Building heat losses can be reduced to a large extent by adding a layer, or layers, of:
A. Insulation
B. Paint
C. Wall paper
D. Glass
E. Building wrap
A. Insulation
- One of the methods of estimating the quantity of air entering a building by means of infiltration is the _____ method.
A. Infiltration
B. Radiation
C. Crack
D. Occupation
E. Convection
C. Crack
- Thermal transmittance or U-factor (U) is the:
A. Thermal heat flow (transmission) through unit areas of a wall, door, window, etc., for every degree temperature difference between the air/fluid inside and the air/fluid outside. (W/m²K or W/m²°C) (Btu/hr/ft²R or Btu/hr/ft²°F)
B. Quantity of heat flow from all mechanisms, in unit time, under the conditions prevailing at that time (Q or W)
C. Thermal heat flow, by conduction only, through a unit area of a single uniform type of material (W/m°C) (Btu/hr/ft²°F)
D. Thermal heat flow through a unit area of a non-uniform, composite material when a unit average temperature difference is established between the surfaces (W/m²°C) (Btu/hr/ft²°F)
E. Reciprocal of thermal conductance, it is the value of a given material’s ability to resist heat transfer or flow (m²°C/W) (ft²°F/Btu/hr
A. Thermal heat flow (transmission) through unit areas of a wall, door, window, etc., for every degree temperature difference between the air/fluid inside and the air/fluid outside. (W/m²K or W/m²°C) (Btu/hr/ft²R or Btu/hr/ft²°F)
- Building external heat gains include those by:
A. Construction
B. Friction
C. Occupation
D. Solar radiation
E. Convection
D. Solar radiation
- The forcing of air into a building by means of fans is called:
A. Infiltration
B. Ventilation
C. Radiation
D. Convection
E. Occupation
B. Ventilation
- Heat energy always moves from:
A. A warmer source to a cooler source
B. Lower levels to higher levels
C. A cooler source to a warmer source
D. Higher levels to lower levels
E. Outside to inside
A. A warmer source to a cooler source
- The wind velocity used to calculate summer infiltration heat gains is:
A. 12 km/h (7.5 mph)
B. 10 km/h (6.2 mph)
C. 24 km/h (14.9 mph)
D. 20 km/h (12.4 mph)
E. 15 km/h (9.3 mph)
A. 12 km/h (7.5 mph)
- Building air infiltration should be kept to a minimum a certain amount of fresh air is required to provide _____ within the building.
A. Heating
B. Ventilation
C. Cooling
D. Dust control
E. Humidification
B. Ventilation
- One of the ways that heat is transmitted is by:
A. Construction
B. Occupation
C. Insulation
D. Convection
E. Conservation
D. Convection
- Thermal resistance (R) is the:
A. Thermal heat flow (transmission) through unit areas of a wall, door, window, etc., for every degree temperature difference between the air/fluid inside and the air/fluid outside. (W/m²K or W/m²°C) (Btu/hr/ft²R or Btu/hr/ft²°F)
B. Quantity of heat flow from all mechanisms, in unit time, under the conditions prevailing at that time (Q or W)
C. Thermal heat flow, by conduction only, through a unit area of a single uniform type of material (W/m°C) (Btu/hr/ft²°F)
D. Thermal heat flow through a unit area of a non-uniform, composite material when a unit average temperature difference is established between the surfaces (W/m²°C) (Btu/hr/ft²°F)
E. Reciprocal of thermal conductance, it is the value of a given material’s ability to resist heat transfer or flow (m²°C/W) (ft²°F/Btu/hr)
E. Reciprocal of thermal conductance, it is the value of a given material’s ability to resist heat transfer or flow (m²°C/W) (ft²°F/Btu/hr)