CEM 350 Exam 1

An energy conservation option has a first cost of $25,000. It requires $2,000 per year maintenance and saves $5,000 per year in utilities. Assume this is installed in a building with 200 occupants, average personnel cost $60,000 per year. If the device interferes with temperature control, resulting in 2% decrease in productivity, what would the simple payback be? A. No payback ever B. $60,00 payback C. $3,000 payback D. $240,000 payback

A

An energy conservation option has a first cost of $25,000. It requires $2,000 per year maintenance and saves $5,000 per year in utilities. The simple payback period is 8 years. This system will last 15 years with no salvage value. What is the 15-year life cycle cost assuming energy cost escalation of 4% annually, maintenance cost escalation 2% annually, and a 15% discount rate? A. $9,684 B. $8.754 C. $17,491 D. $14,703

A

An energy conservation option has a first cost of $25,000. It requires $2,000 per year maintenance and saves $5,000 per year in utilities. The simple payback period is 8 years. This system will last 15 years with no salvage value. What is the 15-year life cycle cost assuming energy cost escalation of 4% annually, maintenance cost escalation 2% annually, and a 5% discount rate? A. $17,491 B. $14,703 C. $9,684 D. $8,754

A

If the lighting load for a 50,000 sq ft building is estimated at 2 Watts/ sq ft, what will be the resulting heat generated by lighting over a ten-hour day? A. 341,000 Btuh B. 100,000 Btuh C. 341,000 Btu D. 100,000 Btu

A

Of all HVAC delivery systems discussed in this chapter, which of the most energy efficient and why? A. Fan terminal systems because they use variable air volume for primary air and totally avoid reheat B. Radiant panel heating and cooling because they can be used in conjunction with VAV systems.

A

Sustainable design inherently produces buildings that exceed minimum requirements of codes and standards. A. True B. False

A

Systems not employing variable air volume are the most energy efficient HVAC delivery systems. A. True B. False

A

The basic difference between interior and perimeter space is that: Perimeter space is exposed to heat loss through the building envelope and may need heat during cold weather. Interior space has no exposure to envelope heat loss and will not need heat during cold weather. A. True B. False

A

The primary energy advantage of using radiant cooling is that it avoids using fans, which consume considerable energy in HVAC systems. A. True B. False

A

What are the major differences between electric or pneumatic control and direct digital control? Electric and pneumatic controls use different media, but are both analog-based, relying on varying voltage or pneumatic pressure to determine control actions. Direct digital control uses numerical calculations to determine control action A. True B. False

A

_______ fan coils have hot and chilled water available at the same time. During cold weather, some zones may still need cooling due to solar loads or internal heat gains while other zones need heating. A________fan coil system is capable of heating or cooling, not both, at the same time. This is why the extra construction cost for is worth it (Note: Include the - mark with no spaces in your answers and do not capitalize) A. four-pipe; two-pipe B. two-pipe; four-pipe C. four-pipe; six-pipe D. six-pipe; four-pipe

A

What principles are used to vary the amount of HVAC service to a space with varying loads? Select all that apply. Systems vary HVAC service by: A. Varying the temperature of the air supplied, holding flow constant B. Varying the flow of warm or cold air supplied, holding temperature constant. C. Varying both the temperature and the flow of air supplied

A, B, C

Name the HVAC delivery systems that are the most flexible for adding or rearranging zones A. Dual Duct B. Terminal reheat C. Fan terminal unit systems D. Variable Refrigerant Flow (VRF) E. Variable air volume

A, B, C, E

A hotel developer is deciding whether to use fan coils or PTAC units. How would you counsel him on matters of cost and quality? Select all that apply. A. The fan coil system will last longer than PTAC before major replacement B. Fan coils are louder than PTAC but cheaper C. Fan coils will be more expensive due to the need for a central plant to produce chilled water and hot water D. PTAC systems are cheaper than fan coils, easier to maintain, and are quieter

A, C

An energy conservation option has a first cost of $25,000. It requires $2,000 per year maintenance and saves $5,000 per year in utilities. Assume this is installed in a building with 200 occupants, average personnel cost $60,000 per year. If the device interferes with temperature control, resulting in 2% increase in productivity, what would the simple payback be? A. $3,000 payback B. $243,000 payback C. $60,000 payback D. No payback ever

B

An energy conservation option has a first cost of $25,000. It requires $2,000 per year maintenance and saves $5,000 per year in utilities. What is the simple payback period for the option? A. 10 years B. 8 years C. 9 years D. 7 years

B

If the initial, incremental cost of air conditioning equipment is $2,500 per ton, how much less would a building with 16 tons of solar load spend compared to a building with 44 tons of solar load. A. $100,000 B. $70.000 C. $26,000 D. $500,000

B

State the factors that affect environmental comfort and their general ranges of values, where applicable. A. Temperature and humidity - low limit values for comfort are 43°F, 30% RH; high limit values for comfort are 90°F, 55% RH. Air motion should be between 50 feet per minute and 100 feet per minute B. Temperature and humidity - low limit values for comfort are 68°F, 30% RH; high limit values for comfort are 79°F, 55%RH. Air motion should be between 10 feet per minute and 50 feet per minute. Radiant effects from cold and warm surfaces can also affect comfort C. Temperature and humidity - low limit values for comfort are 43°F, 30% RH; high limit values for comfort are 90°F, 55% RH. Air motion should be between 50 feet per minute and 110 feet per minute. Radiant effects from cold and warm surfaces can also affect comfort D. Temperature and humidity - low limit values for comfort are 68°F, 0% RH; high limit values for comfort are 79%, 55% RH. Air motion should be between 10 feet per minute and 50 feet per minute. Radiant effects from cold and warm surfaces cannot affect comfort

B

What would the solar load in tons for a proposed building design that has 10,000 sq ft of glass with a shading coefficient of 0.7, if all the glass faced north? A. 23 tons B. 16 tons C. 10 tons D. 44 tons

B

A proposed building design has 10,000 sq ft of glass with shading coefficient 0.7, equally distributed north, south, east, and west. What is the total solar load in tons July 21 at 4:00 pm? A. 105, 050 Btuh B. 220, 700 Btuh C. 523, 300 Btuh D. 765, 900 Btuh

C

Approximately how much steam flow would be required for a 300,000 Btuh heating load? A.3,000 pounds per hour B. 500 pounds per hour C. 300 pounds per hour D. 100 pounds per hour

C

Scenario: 6" thick concrete wall The wall is finished on the interior with ½" drywall, adhesively applied to the surface The drywall is applied over 1.5" furring The furring space is filled with insulation at R-4 per inch Use Tables 2-2, 2-3, and 2-4 for this exercise Question: What will be the U-factor for a wall constructed as follows? A. U = 1 B. U = 0.223 C. U = 0.13 D. U = 0.56

C

What is the rate of removal of moisture required to reduce a 1,000-cfm airstream from 95°F DB, 78°F WB to 75°F, 50% relative humidity? A. 0.0003 pounds per minute B. 1 pound of water per minute C. 0.54 pounds of water per minute D. 0.00005 pounds per minute

C

Will a developer use a higher or lower discount rate than a building owner? Why? A. Developers' profit expectation is higher than that of a building owner as pointed out in class lecture they're taking on more risk, so they will apply a lower discount rate in cash flow analysis B. Developers ' profit expectation is lower than that of a building owner as pointed out in class lecture they're taking on more risk, so they will apply a higher discount rate in cash flow analysis C. Developers' profit expectation is higher than that of a building owner as pointed out in class lecture they're taking on more risk, so they will apply a higher discount rate in cash flow analysis D. Developers' profit expectation is lower than that of a building owner as pointed out in class lecture they're taking on more risk, so they will apply a lower amount rate in cash flow analysis

C

How much water is present in 1 pound of air at 75°F, 50% relative humidity? A. One pound of air at 75°F, 50% relative humidity contains 0.0001 pounds (65 grains) of water B. One pound of air at 75°F, 50% relative humidity contains no pounds of water C. One pound of air at 75°F, 50% relative humidity contains 0.00009 pounds (20 grains) of water D. One pound of air at 75°F, 50% relative humidity contains 0.0093 pounds (65 grains) of water

D

How much water is present in 1 pound of air at 95°F DB(dry bulb), 78°F WB (wet bulb)? A. One pound of air at 95°F DB, 78°F WB contains 0.0001 pounds (50 grains) of water B. One pound of air at 95°F DB, 78°F WB contains 1 pound (200 grains) of water C. One pound of air at 95°F DB, 78°F WB contains no pounds of water D. One pound of air at 95°F DB, 78°F WB contains 0.017 pounds (118 grains) of water

D

If the lighting load for a 50,000 sq ft building is estimated at 2 Watt/sq. Ft, the resulting heat generated by lighting over a ten-hour day is 341,000 Btuh. How much CO2 will be liberated to the atmosphere in a year's time due this lighting operation? A. 840,000 lbs. Greater amounts would be generated if the lighting were operated greater than continuously, or if the power generation were by gas or oil B. 350,000 lbs. Greater amounts would be generated if the lighting were operated greater than continuously, or if the power generation were by gas or oil C. 350,000 lbs. Lesser amounts would be generated if the lighting were operated less than continuously, or if the power generation were by gas or oil D. 840,000 lbs. Lesser amounts would be generated if the lighting were operated less than continuously, or if the power generation were by gas or oil

D

If the lighting load for a 50,000 sq. ft. building is estimated at 2 Watt/ sq ft, the resulting heat generated by lighting over a ten-hour day is 341,000 Btuh. If the lighting load were increased, what would be the effect on other building systems? A. The heat from the lightning will add to the air conditioning load. Increasing lighting load will decrease the size of air conditioning equipment. Requirements for power distribution equipment will also be decreased directly by increased lighting and indirectly by increased air conditioning. Heat from lights might decrease requirements for building heating, but most engineers will not factor lighting into the size of heating equipment since lights may not be on B. If the lighting load were increased, we would need less tint on our windows. The power distribution equipment can power the building just fine C. If you increase the lighting load, the power distribution equipment will disperse the light to the darker rooms to even out the air temperature D. The heat from the lighting will add to the air conditioning load. Increasing lighting load will increase the size of the air conditioning equipment. Requirements for power distribution equipment will also be increased directly by increased lighting and indirectly by increased air conditioning. Heat from lights might decrease requirements for building hearing, but most engineers will not factor lighting into the size of heating equipment since lights may not be on

D

You're helping an owner to decide between VAV terminals and FTU terminals for interior conference rooms in his office building. How would you counsel him on matters of cost and quality? Select all that apply A. VAV terminals are more costly than Fan terminal units B. Fan terminal units are more costly than VAV terminals C. VAV terminal units maintain good air circulation regardless of load. This is very important in conference rooms to avoid stuffiness D. Fan terminal units maintain good air circulation regardless of load. This is very important in conference rooms to avoid stuffiness

D