Residential Energy Audit - Chapter 8

1. The combination of
- radiant temperature
- humidity
- air movement
determine comfort level .

True

Flase

The combination of radiant temperature, humidity, and air movement determines the comfort level. These factors play a significant role in how comfortable a person feels in a particular environment. Radiant temperature refers to the temperature of surrounding surfaces, humidity affects the moisture content in the air, and air movement can impact how heat is distributed. Therefore, considering all three factors is crucial in determining the overall comfort level.

Explanation

The combination of radiant temperature, humidity, and air movement determines the comfort level. These factors play a significant role in how comfortable a person feels in a particular environment. Radiant temperature refers to the temperature of surrounding surfaces, humidity affects the moisture content in the air, and air movement can impact how heat is distributed. Therefore, considering all three factors is crucial in determining the overall comfort level.

2. Absorbed summer sunlight raises wall & ceiling temperatures, making these surfaces radiant heaters.

True

False

The statement suggests that during the summer, sunlight is absorbed by walls and ceilings, causing these surfaces to heat up. As a result, they emit heat in the form of radiation, functioning as radiant heaters. This explanation supports the statement being true.

Explanation

The statement suggests that during the summer, sunlight is absorbed by walls and ceilings, causing these surfaces to heat up. As a result, they emit heat in the form of radiation, functioning as radiant heaters. This explanation supports the statement being true.

3. Air conditioners must remove moisture from the air to improve indoor comfort.

True

False

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Explanation

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4. Solar energy falling on the roof coming trough the windows account for most of a house's solar heat gain.

True

False

Solar energy falling on the roof can enter a house through the windows, leading to solar heat gain. This is because sunlight can pass through windows, and when it does, it can warm up the interior of a house. Therefore, it is true that solar energy falling on the roof and coming through the windows is responsible for most of a house's solar heat gain.

Explanation

Solar energy falling on the roof can enter a house through the windows, leading to solar heat gain. This is because sunlight can pass through windows, and when it does, it can warm up the interior of a house. Therefore, it is true that solar energy falling on the roof and coming through the windows is responsible for most of a house's solar heat gain.

5. Studies by Lawrence Berkley Laboratory estimates that planting trees is ten times more cost effective than building new power plants for summer cooling.

True

False

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Explanation

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6. Evaporative coolers work well in regions where the relative humidity remains at less than ___%

10

50

100

p207

Explanation

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7. SEER apply to

Central air conditioners

Room air conditioners

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Explanation

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8. Dueling managers - residents who move the thermostat to suit their different demands - also cause the air conditioning system to operate inefficiently.

True

False

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Explanation

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9. Split system air conditioner are charge in the field. Often they will have too much or too little refrigerant.

True

False

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Explanation

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10. Relative humidity is the percent at which air at any temperature is ___________ with water vapor.

Relative humidity is the percent at which air at any temperature is saturated with water vapor.

Explanation

Relative humidity is the percent at which air at any temperature is saturated with water vapor.

Submit

12. Energy conservation measures that block the sun before it strikes the roof or windows are the most effective.

True

False

Energy conservation measures that block the sun before it strikes the roof or windows are the most effective in reducing heat gain and preventing the need for excessive cooling. By blocking the sun's rays, these measures can significantly reduce the amount of heat that enters a building, thus reducing the reliance on air conditioning systems and ultimately saving energy. This can be achieved through the use of shading devices such as awnings, blinds, or reflective films on windows, as well as through the strategic placement of trees or vegetation to provide natural shade.

Explanation

Energy conservation measures that block the sun before it strikes the roof or windows are the most effective in reducing heat gain and preventing the need for excessive cooling. By blocking the sun's rays, these measures can significantly reduce the amount of heat that enters a building, thus reducing the reliance on air conditioning systems and ultimately saving energy. This can be achieved through the use of shading devices such as awnings, blinds, or reflective films on windows, as well as through the strategic placement of trees or vegetation to provide natural shade.

13. Southern exposure needs __________ trees to block the sun from the south during the summer.

Shorter

Taller

No

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Explanation

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14. Window sunscreen fabric absorbs ___% to ___% of solar heat before it enters the home.

15 to 20

65 to 70

95 to 100

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Explanation

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15. Window sunscreen must be installed on the __________ of the window to be effective.

Interior

Exterior

Window sunscreen must be installed on the exterior of the window to be effective because it acts as a barrier between the sun's rays and the window. By placing the sunscreen on the outside, it can block the sunlight before it enters the window, reducing heat and glare. Installing it on the interior would allow the sunlight to pass through the window and reach the interior space, diminishing its effectiveness in providing shade and protection.

Explanation

Window sunscreen must be installed on the exterior of the window to be effective because it acts as a barrier between the sun's rays and the window. By placing the sunscreen on the outside, it can block the sunlight before it enters the window, reducing heat and glare. Installing it on the interior would allow the sunlight to pass through the window and reach the interior space, diminishing its effectiveness in providing shade and protection.

16. Window sunscreen must be installed on the exterior of the window to be effective and therefor are not practical for outwardly opening windows such as awning or casement windows, unless attached to movable sash.

True

False

The explanation for the given correct answer is that window sunscreens need to be installed on the exterior of the window in order to be effective. This means that they are not practical for outwardly opening windows like awning or casement windows, unless they are attached to a movable sash. Therefore, the statement "Window sunscreen must be installed on the exterior of the window to be effective and therefore are not practical for outwardly opening windows such as awning or casement windows, unless attached to movable sash" is true.

Explanation

The explanation for the given correct answer is that window sunscreens need to be installed on the exterior of the window in order to be effective. This means that they are not practical for outwardly opening windows like awning or casement windows, unless they are attached to a movable sash. Therefore, the statement "Window sunscreen must be installed on the exterior of the window to be effective and therefore are not practical for outwardly opening windows such as awning or casement windows, unless attached to movable sash" is true.

17. Exterior shutters and shades are commonly more expensive that other method used to block the sun entering the window.

True

False

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Explanation

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18. What does SHGC stand for?

Solar heat gain calculation

Solar heat gain coefficient

Solar high gain cost

SHGC stands for Solar Heat Gain Coefficient. It is a measure of how much solar heat is transmitted through a window or a glazing system. The SHGC value ranges from 0 to 1, with a lower value indicating less solar heat gain and better insulation. This coefficient is used to determine the energy efficiency of windows and helps in designing buildings that optimize natural lighting and reduce the need for artificial cooling or heating.

Explanation

SHGC stands for Solar Heat Gain Coefficient. It is a measure of how much solar heat is transmitted through a window or a glazing system. The SHGC value ranges from 0 to 1, with a lower value indicating less solar heat gain and better insulation. This coefficient is used to determine the energy efficiency of windows and helps in designing buildings that optimize natural lighting and reduce the need for artificial cooling or heating.

19. Powerful whole house fans can create strong house pressures that can cause backdrafting or flame roll out in water heaters. To prevent this one should

Provide adequate window openings

Keep all windows and doors tightly sealed.

To prevent backdrafting or flame roll out in water heaters caused by powerful whole house fans, it is important to provide adequate window openings. This allows for proper ventilation and airflow, preventing the buildup of pressure inside the house. By allowing air to flow freely through the windows, the pressure inside the house can equalize, reducing the risk of backdrafting or flame roll out. Keeping windows and doors tightly sealed, on the other hand, can exacerbate the pressure imbalance and increase the likelihood of these issues occurring.

Explanation

To prevent backdrafting or flame roll out in water heaters caused by powerful whole house fans, it is important to provide adequate window openings. This allows for proper ventilation and airflow, preventing the buildup of pressure inside the house. By allowing air to flow freely through the windows, the pressure inside the house can equalize, reducing the risk of backdrafting or flame roll out. Keeping windows and doors tightly sealed, on the other hand, can exacerbate the pressure imbalance and increase the likelihood of these issues occurring.

20. Room air conditioner performance deteriorates as it accumulates dirt.

True. The air conditioner will eventually breakdown or fail to cool the room.

False. Room air conditioners have a build self cleaning system that eliminate the need for frequent maintenance.

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Explanation

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21. Oversized air conditioning systems waste energy because they cycle more frequently than correctly sized units.

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Explanation

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22. Fiber glass duct liners installed inside metal ducts never deteriorate.

True. Modern fiberglass material resist deterioration very effectively, and therefor eliminate the possibility of obstruction.

False. Deterioration happens because of moisture and vibration and may partially block duct airway.

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Explanation

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23. Efficient appliances produce less waste heat.

True

False

Efficient appliances are designed to minimize energy waste by converting more of the input energy into useful output, such as light or mechanical work, rather than dissipating it as heat. This means that they produce less waste heat compared to less efficient appliances. Therefore, the statement "Efficient appliances produce less waste heat" is true.

Explanation

Efficient appliances are designed to minimize energy waste by converting more of the input energy into useful output, such as light or mechanical work, rather than dissipating it as heat. This means that they produce less waste heat compared to less efficient appliances. Therefore, the statement "Efficient appliances produce less waste heat" is true.

24. Trees and plants that provide shade is the best long term investment for reducing cooling costs

True

False

Trees and plants provide shade, which can significantly reduce cooling costs in the long term. When these natural elements are strategically placed around a building, they can block the sun's rays and prevent heat from entering the structure. This reduces the need for air conditioning and lowers energy consumption. Additionally, trees and plants also release moisture into the air through a process called transpiration, which can further cool the surrounding environment. Therefore, investing in trees and plants that provide shade is a cost-effective and sustainable way to reduce cooling costs.

Explanation

Trees and plants provide shade, which can significantly reduce cooling costs in the long term. When these natural elements are strategically placed around a building, they can block the sun's rays and prevent heat from entering the structure. This reduces the need for air conditioning and lowers energy consumption. Additionally, trees and plants also release moisture into the air through a process called transpiration, which can further cool the surrounding environment. Therefore, investing in trees and plants that provide shade is a cost-effective and sustainable way to reduce cooling costs.

25. Older types of metalized film do have the disadvantage of blocking out daylight in addition to solar heat.

True

False

Older types of metalized film do block out daylight in addition to solar heat. This means that when these films are applied to windows, they not only reduce the amount of solar heat entering the building but also limit the natural light coming through the windows. This can be a disadvantage in situations where maintaining natural light is important, such as in residential or office spaces where occupants prefer a well-lit environment. Therefore, the statement "Older types of metalized film do have the disadvantage of blocking out daylight in addition to solar heat" is true.

Explanation

Older types of metalized film do block out daylight in addition to solar heat. This means that when these films are applied to windows, they not only reduce the amount of solar heat entering the building but also limit the natural light coming through the windows. This can be a disadvantage in situations where maintaining natural light is important, such as in residential or office spaces where occupants prefer a well-lit environment. Therefore, the statement "Older types of metalized film do have the disadvantage of blocking out daylight in addition to solar heat" is true.

26. Replacement windows are a cost effective measure for reducing cooling costs.

True

False

Replacement windows are not a cost-effective measure for reducing cooling costs. While new windows may provide some insulation and energy efficiency benefits, the cost of replacing windows is often high and may not provide enough savings in cooling costs to justify the expense. Other measures such as insulation, sealing air leaks, and using energy-efficient appliances and HVAC systems are typically more effective and cost-efficient in reducing cooling costs. Therefore, the statement is false.

Explanation

Replacement windows are not a cost-effective measure for reducing cooling costs. While new windows may provide some insulation and energy efficiency benefits, the cost of replacing windows is often high and may not provide enough savings in cooling costs to justify the expense. Other measures such as insulation, sealing air leaks, and using energy-efficient appliances and HVAC systems are typically more effective and cost-efficient in reducing cooling costs. Therefore, the statement is false.

27. Visible transmittance measures how much light passes through the window glass.

True

False

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Explanation

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28. The best controls for evaporative coolers are reprogrammable thermostats specifically designed for evaporative coolers.

True

False

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Explanation

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29. The energy ratings of air conditioners are based on how many BTUs per hour the unit can remove of each watt of power it draws.

True

False

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Explanation

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30. Relative humidity below 40% discourage biological pests linked to respiratory problems.

True

False

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Explanation

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31. Thermostats often do not provide good comfort control in humid climates.

Manufactures have developed controls that respond to both temperature and humidity.

A shortcoming of all air conditioning units are that it is impossible to control humidity and temperature separately.

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Explanation

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32. __________ temperature accounts for the heat carried by the air's humidity.

Dry Bulb

Wet Bulb

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Explanation

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33. The most cost effective strategies for improving cooling efficiency are different from the strategies to improve heating efficiency. For example Shade trees will reduce the need for air conditioning but will not reduce the need for heating consumption.

True

False

Shade trees can effectively reduce the need for air conditioning by providing shade and blocking direct sunlight, which can help in keeping the surrounding area cooler. However, shade trees do not have a direct impact on heating consumption as they do not provide any insulation or heat retention properties. Therefore, it is true that shade trees can reduce the need for air conditioning but not the need for heating consumption.

Explanation

Shade trees can effectively reduce the need for air conditioning by providing shade and blocking direct sunlight, which can help in keeping the surrounding area cooler. However, shade trees do not have a direct impact on heating consumption as they do not provide any insulation or heat retention properties. Therefore, it is true that shade trees can reduce the need for air conditioning but not the need for heating consumption.

34. Window glass with low solar heat gain coefficient (SHGC) will reduce cooling load, but heating efficient is improved by windows with a low U-factor.

True

False

Windows with a low solar heat gain coefficient (SHGC) allow less solar heat to enter a building, reducing the cooling load. On the other hand, windows with a low U-factor have better insulation properties, reducing heat loss and improving heating efficiency. Therefore, the statement is true as both low SHGC and low U-factor contribute to reducing the energy required for cooling and heating respectively.

Explanation

Windows with a low solar heat gain coefficient (SHGC) allow less solar heat to enter a building, reducing the cooling load. On the other hand, windows with a low U-factor have better insulation properties, reducing heat loss and improving heating efficiency. Therefore, the statement is true as both low SHGC and low U-factor contribute to reducing the energy required for cooling and heating respectively.

35. ___________ & ____________ determine the rate that a human body can loose heat.

Shading & windows

Air temperature & radiant temperature

Air conditioning systems and window size

The rate at which a human body can lose heat is determined by both the air temperature and the radiant temperature. Air temperature refers to the temperature of the surrounding air, while radiant temperature refers to the temperature of objects or surfaces in the environment that emit or absorb heat. Both factors play a role in heat transfer from the body to the surroundings.

Explanation

The rate at which a human body can lose heat is determined by both the air temperature and the radiant temperature. Air temperature refers to the temperature of the surrounding air, while radiant temperature refers to the temperature of objects or surfaces in the environment that emit or absorb heat. Both factors play a role in heat transfer from the body to the surroundings.

36. ____________ is the temperature at which condensation begins.

Relative humidity

Minimum temperature

Dew point

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Explanation

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37. Trees and shrubs create a micro climate, increasing the shaded area's temperature.

True

False

Trees and shrubs actually create a cooler microclimate by providing shade and reducing the amount of direct sunlight that reaches the ground. The shade helps to lower the temperature in the shaded area, making it cooler than the surrounding open areas. Therefore, the statement that trees and shrubs increase the shaded area's temperature is incorrect.

Explanation

Trees and shrubs actually create a cooler microclimate by providing shade and reducing the amount of direct sunlight that reaches the ground. The shade helps to lower the temperature in the shaded area, making it cooler than the surrounding open areas. Therefore, the statement that trees and shrubs increase the shaded area's temperature is incorrect.

38. Tinted film is as effective as metalized film.

True

False

The statement suggests that tinted film is equally effective as metalized film, but the correct answer is false. This implies that tinted film is not as effective as metalized film.

Explanation

The statement suggests that tinted film is equally effective as metalized film, but the correct answer is false. This implies that tinted film is not as effective as metalized film.

39. Internal heat gain can be limited by:
- limiting the use of hot water
- using exhaust fans to remove moisture
- reducing coking during the heat of the day

True

False

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Explanation

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40. Maintenance and service of air conditioning system to maximize efficiency includes:

Clean or replace filters

Clean supply & return registers

Clean blower fan blades

Clean evaporator coils

Clean condenser coils

The correct answer includes a list of maintenance and service tasks that should be performed on an air conditioning system to maximize its efficiency. These tasks include cleaning or replacing filters, cleaning supply and return registers, cleaning blower fan blades, cleaning evaporator coils, and cleaning condenser coils. By regularly performing these tasks, the air conditioning system can operate more efficiently, providing better cooling and potentially reducing energy consumption.

Explanation

The correct answer includes a list of maintenance and service tasks that should be performed on an air conditioning system to maximize its efficiency. These tasks include cleaning or replacing filters, cleaning supply and return registers, cleaning blower fan blades, cleaning evaporator coils, and cleaning condenser coils. By regularly performing these tasks, the air conditioning system can operate more efficiently, providing better cooling and potentially reducing energy consumption.

Submit

41. Circulating air inside your home will:

Make you feel cooler

Increases evaporation of sweat

Carries heat away from your skin

Have no significant effect on your comfort level

Circulating air inside your home will make you feel cooler because it helps to increase the evaporation of sweat from your skin. When sweat evaporates, it takes away heat from your body, resulting in a cooling effect. Additionally, the circulating air carries away the heat that is radiated from your skin, further contributing to the feeling of coolness. Therefore, circulating air has a significant effect on your comfort level by reducing the perceived temperature and enhancing the cooling process.

Explanation

Circulating air inside your home will make you feel cooler because it helps to increase the evaporation of sweat from your skin. When sweat evaporates, it takes away heat from your body, resulting in a cooling effect. Additionally, the circulating air carries away the heat that is radiated from your skin, further contributing to the feeling of coolness. Therefore, circulating air has a significant effect on your comfort level by reducing the perceived temperature and enhancing the cooling process.

Submit

42. Internal heat gains refer to

Heat gain from the sun's rays coming through a window

Heat gain from the heated ceilings and walls

Heat gains from lightning, refrigeration, water heating, other appliances and the body of heat from the people inside the house.

Internal heat gains refer to the heat generated within a building by various sources such as lightning, refrigeration systems, water heating, appliances, and the body heat produced by the occupants. These sources contribute to the overall heat load within the building, impacting its temperature and energy consumption. By understanding and managing internal heat gains, building owners and designers can optimize energy efficiency and thermal comfort.

Explanation

Internal heat gains refer to the heat generated within a building by various sources such as lightning, refrigeration systems, water heating, appliances, and the body heat produced by the occupants. These sources contribute to the overall heat load within the building, impacting its temperature and energy consumption. By understanding and managing internal heat gains, building owners and designers can optimize energy efficiency and thermal comfort.

43. Air leakage contribute to about 20% of summer heat gain.

True

False

Air leakage refers to the unintentional flow of air in and out of a building through cracks, gaps, and openings in the building envelope. During the summer, hot air from outside can enter the building through these leaks, leading to increased heat gain. This additional heat can contribute to about 20% of the total heat gain in a building during the summer months. Therefore, the statement "Air leakage contributes to about 20% of summer heat gain" is true.

Explanation

Air leakage refers to the unintentional flow of air in and out of a building through cracks, gaps, and openings in the building envelope. During the summer, hot air from outside can enter the building through these leaks, leading to increased heat gain. This additional heat can contribute to about 20% of the total heat gain in a building during the summer months. Therefore, the statement "Air leakage contributes to about 20% of summer heat gain" is true.

44. Replacing an air conditioner rated at SEER 6 with one that is rated SEER 12 will

Cut your cooling cost in half

Double your cooling costs

p210

Explanation

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45. 1 Ton of cooling = ____________ BTUs/H

10 000

11 000

12 000

14 200

p211

Explanation

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46. Superheat and subcooling must generally be done during the heating season.

True

False

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Explanation

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47. Ventilation works well when the relative humidity is up to _____%.

100%

90%

80%

70%

10%

Ventilation works well when the relative humidity is up to 70%. This is because excessive humidity can lead to the growth of mold and mildew, which can cause health issues and damage to the building. By keeping the relative humidity below 70%, ventilation helps to prevent the buildup of moisture and maintain a healthier and more comfortable indoor environment.

Explanation

Ventilation works well when the relative humidity is up to 70%. This is because excessive humidity can lead to the growth of mold and mildew, which can cause health issues and damage to the building. By keeping the relative humidity below 70%, ventilation helps to prevent the buildup of moisture and maintain a healthier and more comfortable indoor environment.

48. Awnings on the south side need a drop measurement of ___% to ___% of the window height to block solar radiation from high in the sky.

15 to 20

45 to 60

85 to 100

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Explanation

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49. Low humidity helps reduce cooling energy consumption, but not heating consumption.

True

False

Low humidity helps reduce cooling energy consumption because when the air is dry, it can hold more heat, allowing the cooling system to work more efficiently. On the other hand, low humidity does not have a significant impact on heating consumption because heating systems primarily rely on raising the temperature of the air rather than the moisture content. Therefore, the statement is true.

Explanation

Low humidity helps reduce cooling energy consumption because when the air is dry, it can hold more heat, allowing the cooling system to work more efficiently. On the other hand, low humidity does not have a significant impact on heating consumption because heating systems primarily rely on raising the temperature of the air rather than the moisture content. Therefore, the statement is true.

50. In most climates solar heat gain contributes about ___% of the total heat accumulation indoors.

30%

50%

90%

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Explanation

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51. EER apply to

Room air conditioners

Central air conditioners

EER, which stands for Energy Efficiency Ratio, is a measure of the cooling efficiency of air conditioners. It is calculated by dividing the cooling capacity of the unit by its power consumption. EER is typically used to evaluate the energy efficiency of smaller cooling systems, such as room air conditioners. Central air conditioners, on the other hand, are usually evaluated using a different metric called SEER (Seasonal Energy Efficiency Ratio). Therefore, the correct answer is room air conditioners.

Explanation

EER, which stands for Energy Efficiency Ratio, is a measure of the cooling efficiency of air conditioners. It is calculated by dividing the cooling capacity of the unit by its power consumption. EER is typically used to evaluate the energy efficiency of smaller cooling systems, such as room air conditioners. Central air conditioners, on the other hand, are usually evaluated using a different metric called SEER (Seasonal Energy Efficiency Ratio). Therefore, the correct answer is room air conditioners.

52. You find an EER 10 on the energy guide lable of an room air conditioner. What would be a reasonable conclusion?

The unit has poor efficiency

The unit has moderate efficiency

The unit has high efficiency

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Explanation

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53. When selecting an air conditioner consider

Moisture removal

Cooling

Energy efficiency

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Explanation

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Submit

54. SHF (Sensible Heat Factor) refers to the moisture removal capacity of an air conditioning system

Moisture removal capacity of an air conditioning system

Heat removal capacity of an air conditioning system

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Explanation

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55. Home owner A lives in Florida. Home owner B lives in Colorado. What would be a proper SHF rating for each of the home owners?

Home owner A: SHF 0.67 Home owner B: SHF 0.8

Home owner A: SHF 0.8 Home owner B: SHF 0.67

Home owner A: SHF 0.8 Home owner B: SHF 0.8

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Explanation

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56. Central air conditioners are designed to cool the entire house. Indicate another the correct statement.

Closing registers in unused room will not usually save energy.

Closing registers in unused room will save energy.

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Explanation

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57. Humid air suppresses the evaporation of sweat which cause discomfort..

True

False

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Explanation

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58. Solar heat gain coefficient is:

The amount of light that is admitted through the window.

p203

Explanation

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59. An oversized new air conditioner or one with mismatched parts

Won't reach its potential high efficiency

Won't remove enough moisture to provide adequate comfort.

p212

Explanation

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Submit

60. In order to improve circulation, comfort and reduce house pressures install the following:

Wall grilles

Door grilles

Jumper ducts

Installing wall grilles, door grilles, and jumper ducts helps to improve circulation, comfort, and reduce house pressures. Wall grilles allow air to flow freely between rooms, promoting better air circulation. Door grilles provide a pathway for air to move between rooms, balancing pressure and preventing discomfort caused by closed doors. Jumper ducts connect rooms that have significant temperature differences, allowing air to transfer and equalize the temperature throughout the house. Overall, the installation of these components helps to create a more comfortable and balanced indoor environment.

Explanation

Installing wall grilles, door grilles, and jumper ducts helps to improve circulation, comfort, and reduce house pressures. Wall grilles allow air to flow freely between rooms, promoting better air circulation. Door grilles provide a pathway for air to move between rooms, balancing pressure and preventing discomfort caused by closed doors. Jumper ducts connect rooms that have significant temperature differences, allowing air to transfer and equalize the temperature throughout the house. Overall, the installation of these components helps to create a more comfortable and balanced indoor environment.

Submit

61. East and west vegetation should block ____________sun during the summer.

Lower-angle

Higher-angle

Only the afternoon

During the summer, the sun is higher in the sky, so if the vegetation blocks the lower-angle sun, it will provide shade and help to keep the area cooler. Blocking the higher-angle sun would not provide as much shade and may not effectively block the direct sunlight. Only blocking the afternoon sun would not be sufficient as the sun's angle changes throughout the day and vegetation should block the sun for a longer period to provide adequate shade.

Explanation

During the summer, the sun is higher in the sky, so if the vegetation blocks the lower-angle sun, it will provide shade and help to keep the area cooler. Blocking the higher-angle sun would not provide as much shade and may not effectively block the direct sunlight. Only blocking the afternoon sun would not be sufficient as the sun's angle changes throughout the day and vegetation should block the sun for a longer period to provide adequate shade.

62. Air conditioning unit A has SHF rating of 0.5

Air conditioning unit B has SHF rating of 1.0

Which will remove the most moisture from the air inside the home.

A: The lower the SHF rating the more moisture is removed by the unit

B: The higher the SHF rating the more moisture is removed by the unit

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Explanation

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63. Window glass with low solar heat gain coefficient (SHGC) will reduce heating load.

True

False

Window glass with low solar heat gain coefficient (SHGC) will not reduce heating load. The solar heat gain coefficient (SHGC) measures how much heat from the sun is transmitted through the window. A low SHGC means that less heat is transmitted, which is desirable in hot climates to reduce cooling loads. However, in colder climates, windows with a higher SHGC are preferred as they allow more solar heat to enter the building and reduce the need for heating. Therefore, window glass with low SHGC will not reduce heating load.

Explanation

Window glass with low solar heat gain coefficient (SHGC) will not reduce heating load. The solar heat gain coefficient (SHGC) measures how much heat from the sun is transmitted through the window. A low SHGC means that less heat is transmitted, which is desirable in hot climates to reduce cooling loads. However, in colder climates, windows with a higher SHGC are preferred as they allow more solar heat to enter the building and reduce the need for heating. Therefore, window glass with low SHGC will not reduce heating load.

64. The _____________ determines the rate that a human body can reject heat by evaporation of sweat.

Air flow

Relative convection

Relative humidity

Dew point

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Explanation

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65. Evaporative coolers are a excellent energy saving option for locations with high humidity & high dew point.

True

False

Evaporative coolers are not an excellent energy-saving option for locations with high humidity and high dew point. This is because evaporative coolers work by adding moisture to the air, and in humid conditions, there is already a high level of moisture present. Therefore, using evaporative coolers in such locations would only increase the humidity and make the air feel even more uncomfortable. In these situations, other cooling options like air conditioners would be more suitable.

Explanation

Evaporative coolers are not an excellent energy-saving option for locations with high humidity and high dew point. This is because evaporative coolers work by adding moisture to the air, and in humid conditions, there is already a high level of moisture present. Therefore, using evaporative coolers in such locations would only increase the humidity and make the air feel even more uncomfortable. In these situations, other cooling options like air conditioners would be more suitable.

66. Sealing ducts to stop air leakage pays the fast dividend on air conditioning costs.

True

False

True and duct repair should also include the elimination of pressure differences caused by air leakage and poorly designed systems.

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Explanation

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67. Air conditioning efficiency Improvements made in recent years include:

Variable speed or two-speed motors

Copper tubing grooved inside to increase surface area

Improved electrical motor design

Dual speed compressors

Time delay relays controlling evaporative fans

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Explanation

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Submit

68. Shading & _____________ (the process by which a plant releases water vapor) from trees can reduce the air temperature by as much as 9 deg F compared to unshaded areas.

Evapostatic

Evapotranmisson

Evapotranspiration

Shading and evapotranspiration (the process by which a plant releases water vapor) from trees can reduce the air temperature by as much as 9 deg F compared to unshaded areas.

Explanation

Shading and evapotranspiration (the process by which a plant releases water vapor) from trees can reduce the air temperature by as much as 9 deg F compared to unshaded areas.

69. When the air conditioning system is operating, temperature drop between supply and return air should be _____________________________________ temperature

2 deg F to 3 deg F dry bulb or 20 deg F to 30 deg F wet bulb

15 deg F to 21 deg F dry bulb or 8 deg F to 12 deg F wet bulb

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Explanation

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70. Manufacturers say that technicians should verify the airflow prior to checking the charge , because the charge measurements are not accurate unless airflow of _____ CFM per ton, give or take 80CFM, of cooling capacity.

100

200

300

400

500

p215

Explanation

p215

71. A well planned landscaping program can reduce an unshaded home's summer air conditioning costs by ___% to ___%.

5 to 10

10 to 50

50 to 100

A well planned landscaping program can reduce an unshaded home's summer air conditioning costs by 10% to 50%. This is because strategically placed trees and plants can provide shade to the home, reducing the amount of direct sunlight that enters the house and therefore lowering the need for air conditioning. Additionally, trees can also create a cooling effect through evapotranspiration, where water evaporates from their leaves, further reducing the temperature around the house. By implementing a well-designed landscaping program, homeowners can significantly decrease their summer air conditioning costs.

Explanation

A well planned landscaping program can reduce an unshaded home's summer air conditioning costs by 10% to 50%. This is because strategically placed trees and plants can provide shade to the home, reducing the amount of direct sunlight that enters the house and therefore lowering the need for air conditioning. Additionally, trees can also create a cooling effect through evapotranspiration, where water evaporates from their leaves, further reducing the temperature around the house. By implementing a well-designed landscaping program, homeowners can significantly decrease their summer air conditioning costs.

72. Awnings on the west & east side need a drop measurement of ___% to ___% of the window height to block solar radiation from lower in the sky.

10 to 25

60 to 75

85 to 100

Awnings on the west and east side need a drop measurement of 60% to 75% of the window height to block solar radiation from lower in the sky. This range allows the awnings to effectively shade the window and prevent direct sunlight from entering the space, reducing heat gain and the need for excessive cooling. A drop measurement within this range ensures that the awnings cover a significant portion of the window, providing optimal protection against solar radiation.

Explanation

Awnings on the west and east side need a drop measurement of 60% to 75% of the window height to block solar radiation from lower in the sky. This range allows the awnings to effectively shade the window and prevent direct sunlight from entering the space, reducing heat gain and the need for excessive cooling. A drop measurement within this range ensures that the awnings cover a significant portion of the window, providing optimal protection against solar radiation.

73. Ceiling fans, floor fans and table fans cool the air.

True

False

p207

Explanation

p207

74. Which of the following factors that are true for when you consider shading windows?

Direction of windows

Location of natural shade

All windows, even windows shaded by trees, should be covered by an awning.

Shading devices for larger windows are more cost effective than smaller windows.

Shading devices offer the same cost effective savings for large windows as it does for smaller windows.

The direction of windows is an important factor to consider when shading windows because it determines the amount of sunlight that enters the room throughout the day. The location of natural shade is also important as it can help block direct sunlight and reduce the need for additional shading devices. Shading devices for larger windows are more cost effective than smaller windows because they cover a larger surface area and provide more shade. However, the statement that shading devices offer the same cost effective savings for large windows as it does for smaller windows is not true.

Explanation

The direction of windows is an important factor to consider when shading windows because it determines the amount of sunlight that enters the room throughout the day. The location of natural shade is also important as it can help block direct sunlight and reduce the need for additional shading devices. Shading devices for larger windows are more cost effective than smaller windows because they cover a larger surface area and provide more shade. However, the statement that shading devices offer the same cost effective savings for large windows as it does for smaller windows is not true.

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75. A reflective glass window has a shading coefficient of 0.55. The window glass will transmit ___% of the solar energy compared to that of clear glass.

0.55

5.5

55

Less than zero

p 203

Explanation

p 203

76. The effectiveness of ventilation cooling depends on:

The temperature and humidity of evening and morning air.

The amount of shade around the building

Closing of windows and shades at the proper time

Turning fans on at the proper time

p205

Explanation

p205

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77. SHF depend on the

Size

Construction of the evaporative coil.

Fan speed

p212

Explanation

p212

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78. Split system air conditioners:

Have both the evaporator and condenser outdoors.

Install in a window and is suited for mild climates where residents use it occasionally.

Have evaporator indoors and the condenser outdoors.

Uses an evaporator in every room with a single condenser outside.

Have no ducts

p209

Explanation

p209

79. One ton per 400 square feet of floor space is a good alternative rule of thumb to using complicated calculations for sizing air conditioning systems.

True. Energy Star standards implemented this rule of thumb in 2003

p211

Explanation

p211

80. There should be about 400 cubic ft per minute (CFM) airflow in the system for each ton of air-conditioning capacity. Indicate another the correct statement related to airflow.

p213

Explanation

p213

81. Metalized window plastic film can block _____% to ____% of solar heat on single pane glass.

10 to 25

30 to 40

50 to 75

p201

Explanation

p201

82. Heat gain through air leakage is especially severe in home with air conditioning duct work in the attic. Duct leakage wastes cooling energy by

Allowing cooled air to escape the supply ducts.

Allowing hot humid air to enter the return ducts

Creating pressure differences between indoors and outdoors that drive air leakage through the building shell.

p204

Explanation

p204

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83. When the air conditioning system is operating, temperature drop between supply and return air should be 15 deg F to 21 deg F dry bulb or 8 deg F to 12 deg F wet bulb temperature. A reading outside these ranges can indicate a problem with

Airflow

Refrigerant charge

p214

Explanation

p214

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84. Technicians may advice the following to improve airflow:

Clean the evaporator

Increase fan speed

Enlarging the supply ducts

Enlarging the return ducts

p214

Explanation

p214

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85. Of the four heat gain factors (solar gains, internal gains, air leakage, heat transmission), heat transmission trough the shell of the house is the most important.

True

False

p199

Explanation

p199

86. An air conditioner's capacity is determined by

Heat gain during the hottest weather

The most humid weather

p211

Explanation

p211

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87. Indicate the methods below that are considered the most accurate test for proper airflow.

Duct blower method

Flow plate method

Flow hood method

p214

Explanation

p214

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88. Select the option below that are in order of least expensive (best return on investment) to most expensive (lesser return on investment).

Awnings; sun screen; Trees

Trees, sun screens, awnings

Sunscreen, trees, awnings

p202

Explanation

p202

89. The most important considerations in choosing an awning design are:

Canvas color

Amount of shade desired.

Importance of maintaining a view out the window.

Cost of the awning.

p202

Explanation

p202

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90. Shading coefficient is

A percentage amount that compares window glass' transmittance with that of window awnings.

A percentage amount that compares window glass' transmittance with that of clear glass.

A decimal number that compares window glass' transmittance with that of clear glass.

p203

Explanation

p203

91. Aspen pads can be soaked in soapy water to remove dirt and then rotated to distribute the wear, dirt and scale, which remains after cleaning. Pads should be replace when they become unabsorbent, thin and loaded with scale and dirt. Identy other important maitenenace tasks for evaporative coolers.

Drain and clean the reservoir

Test the operation of the drip tube or dump pump.

Clean fan blades

Clean louvers and fan blades

Oil fan motor and check belt tension.

p208

Explanation

p208

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92. Select the correct statement(s) below:

Refrigerant collect heat at he evaporator coil and releases it at the condenser coil.

Refrigerant collect heat at he condenser coil and releases it at the evaporator coil.

A compressor forces refrigerant through the circuit of pipes and coils

p208

Explanation

p208

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93. Equation: BTU per hour removed devided by watts of electricity power drawn equals _______________

SEER

EER

SHGC

p210

Explanation

p210

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94. You are evaluating the cycling of an existing air conditioner: You find that the air conditioner running constantly. What conclusion(s) can you come to?

The unit is properly sized

The unit is oversized and is straining to overcome maintenance problems, repair or adjustment problems.

It could be undersized

p212

Explanation

p212

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95. Two commonly listed measurements are ____________ and _____________, which are the number of degrees the refrigerant is heated or cooled from its saturation temperature. Saturation is the point when liquid and vapour exists in both the evaporator and the condenser.

Superheat

Supercooling

Subheat

Subcooling

p215

Explanation

p215

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96. Heat transmission typically represents around ____% of the total load.

10

20

50

Heat transmission typically represents around 10% of the total load. This means that only a small portion of the total load is attributed to heat transmission. The majority of the load is likely composed of other factors such as conduction, convection, and radiation.

Explanation

Heat transmission typically represents around 10% of the total load. This means that only a small portion of the total load is attributed to heat transmission. The majority of the load is likely composed of other factors such as conduction, convection, and radiation.

97. Packaged air conditiners

Are used when there is no space to install ducts

Install in a window and is suited for mild climates where residents use it occasionally.

Have evaporator and the condenser outdoors.

Uses an evaporator in every room with a single condenser outside.

Have no ducts

Packaged air conditioners are used when there is no space to install ducts, and they are installed in a window. They are suited for mild climates where residents use them occasionally. The correct answer states that packaged air conditioners have the evaporator and the condenser outdoors. This means that the cooling process takes place outside the building, allowing for efficient cooling without the need for ducts.

Explanation

Packaged air conditioners are used when there is no space to install ducts, and they are installed in a window. They are suited for mild climates where residents use them occasionally. The correct answer states that packaged air conditioners have the evaporator and the condenser outdoors. This means that the cooling process takes place outside the building, allowing for efficient cooling without the need for ducts.

98. A home's cooling energy consumption depends on:

Shading

Window-U factors.

Making it as reflective as possible.

The use of night time ventilation.

Heat tolerance of the it's residents.

The cooling energy consumption of a home depends on several factors. Shading plays a role in reducing the amount of direct sunlight that enters the home, thus reducing the need for cooling. Making the home as reflective as possible helps to reflect sunlight and heat away from the home, also reducing the need for cooling. The use of night time ventilation allows for cooler air to enter the home during the night, reducing the need for mechanical cooling. Finally, the heat tolerance of the home's residents affects the amount of cooling needed, as individuals with higher heat tolerance may require less cooling.

Explanation

The cooling energy consumption of a home depends on several factors. Shading plays a role in reducing the amount of direct sunlight that enters the home, thus reducing the need for cooling. Making the home as reflective as possible helps to reflect sunlight and heat away from the home, also reducing the need for cooling. The use of night time ventilation allows for cooler air to enter the home during the night, reducing the need for mechanical cooling. Finally, the heat tolerance of the home's residents affects the amount of cooling needed, as individuals with higher heat tolerance may require less cooling.

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99. Room air conditioners:

Have both the evaporator and condenser outdoors.

Install in a window and is suited for mild climates where residents use it occasionally.

Have evaporator indoors and the condenser outdoors.

Uses an evaporator in every room with a single condenser outside.

Have no ducts

p209

Explanation

p209

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100. Air conditioning capacity is measured in:

KW

KWh

BTUs/hour

Tons of cooling

p211

Explanation

p211

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101. Obstructions in the supply air ducts include

Dents

Debris

Bent registers

Dirty registers

Missing registers

The correct answer includes various obstructions that can occur in the supply air ducts. Dents in the ducts can restrict or block the airflow, reducing the efficiency of the system. Debris such as dust, dirt, or other particles can accumulate in the ducts and obstruct the airflow. Bent registers can also impede the proper flow of air. Similarly, dirty registers, which are the grilles or vents through which the air is released into the room, can hinder the airflow. Lastly, missing registers can create gaps in the duct system, leading to air leakage and reduced efficiency.

Explanation

The correct answer includes various obstructions that can occur in the supply air ducts. Dents in the ducts can restrict or block the airflow, reducing the efficiency of the system. Debris such as dust, dirt, or other particles can accumulate in the ducts and obstruct the airflow. Bent registers can also impede the proper flow of air. Similarly, dirty registers, which are the grilles or vents through which the air is released into the room, can hinder the airflow. Lastly, missing registers can create gaps in the duct system, leading to air leakage and reduced efficiency.

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102. You find an EER 7.5 on the energy guide lable of an room air conditioner. What would be a reasonable conclusion?

The unit has high efficiency

The unit has moderate efficiency

The unit has poor efficiency

The unit was build before Jan 1, 1990

p210

Explanation

p210

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103. Select the correct statement(s) below:

An air conditioner cools your home with cold indoor coil called the condenser.

An air conditioner cools your home with cold indoor coil called the evaporator.

A hot outdoor coil, called the condenser releases the collected heat outdoors.

A hot outdoor coil, called the evaporator releases the collected heat outdoors.

Fans move air through these hot and cold coil coils

The correct answer is that an air conditioner cools your home with a cold indoor coil called the evaporator. The evaporator coil absorbs heat from the indoor air, causing it to cool down. A hot outdoor coil, called the condenser, releases the collected heat outdoors. Fans are responsible for moving air through both the hot and cold coils, facilitating the cooling process.

Explanation

The correct answer is that an air conditioner cools your home with a cold indoor coil called the evaporator. The evaporator coil absorbs heat from the indoor air, causing it to cool down. A hot outdoor coil, called the condenser, releases the collected heat outdoors. Fans are responsible for moving air through both the hot and cold coils, facilitating the cooling process.

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104. In roofs, radiant barriers reflect heat radiation coming towards them. Which of the following is also true?

Impede heat flow by being poor emitters of heat radiation.

Radiant barriers must face an air space with their shiny surface to be effective.

A vertical air film bordered by a radiant barrier has double the R value of one bordered by common materials.

An air film's R value is not affected by air convection

Radiant barriers impede heat flow by being poor emitters of heat radiation. This means that they are not able to transfer heat through radiation as effectively as other materials. Additionally, radiant barriers must face an air space with their shiny surface to be effective. This is because the shiny surface reflects the heat radiation back towards the source, preventing it from entering the space. Finally, a vertical air film bordered by a radiant barrier has double the R value of one bordered by common materials. The R value measures the resistance to heat flow, so this indicates that the radiant barrier significantly improves the insulation properties of the air film.

Explanation

Radiant barriers impede heat flow by being poor emitters of heat radiation. This means that they are not able to transfer heat through radiation as effectively as other materials. Additionally, radiant barriers must face an air space with their shiny surface to be effective. This is because the shiny surface reflects the heat radiation back towards the source, preventing it from entering the space. Finally, a vertical air film bordered by a radiant barrier has double the R value of one bordered by common materials. The R value measures the resistance to heat flow, so this indicates that the radiant barrier significantly improves the insulation properties of the air film.

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