Refrigeration and Air Conditioning Technology (MindTap Course List)
8th Edition
ISBN: 9781305578296
Author: John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher: Cengage Learning
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Textbook Question
Chapter 50, Problem 11RQ
The most efficient way to establish the best possible economizer position is to measure
A. the dry-bulb temperature of the return and outside airstreams.
B. the dry-bulb temperature of the return air and the enthalpy of the outside air.
C. the enthalpy of the return air and the dry-bulb temperature of the outside air.
D. the enthalpy of both the return air and the outside air.
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Recirculated air from the indoor space is 7,500 cfm (75 degrees F dry bulb, 50% RH). Ventilation air from outdoors is 2,500 cfm (95 degrees F dry bulb, 76 degrees F wet bulb). Leaving air off the cooling coil is 10,000 cfm (55 degrees F dry bulb, 90% RH). What is the wet bulb temperature of the indoor air that is being recirculated?
Group of answer choices
61.5 degrees
63.5 degrees
62.5 degrees
61 degrees
Pick the right combination of True Statements.
1. As the by-pass factor (BPF) of the cooling coil increases, temperature difference
between air at the outlet of the coil and coil ADP decreases.
2. As the by-pass factor (BPF) of the cooling coil increases, temperature difference
between air at the outlet of the coil and coil ADP increases.
3. During cooling and humidification process, the enthalpy of air may increase, decrease
or remain constant depending upon the temperature of the wet surface.
4. During sensible cooling of air, dry bulb temperature decreases but wet bulb
temperature remains constant
5. The sensible heat factor for a sensible heating process is 1.0
A domestic refrigerator sits in a kitchen, switched on, with the refrigerator door wide open.
The kitchen itself is well insulated and it can be assumed no heat can escape or enter the kitchen from the outside.
Which of the following is the most accurate statement.
а.
The temperature in the kitchen will stay the same.
O b. The temperature in the kitchen could go up or down depending on the mechanical efficiency of the compressor.
O c.
The temperature in the kitchen will go down very slightly.
d. The temperature in the kitchen could go up or down, depending on the Coefficient of Performance (COP) of the refrigerator.
е.
The temperature in the kitchen will go up very slightly.
Chapter 50 Solutions
Refrigeration and Air Conditioning Technology (MindTap Course List)
Ch. 50 - Which of the following is true regarding the...Ch. 50 - Which process would best represent the opposite of...Ch. 50 - Mixed air is best described as the combination of...Ch. 50 - Which of the following should be taken into...Ch. 50 - A bonded roof is one that has A. reinforced steel...Ch. 50 - Properly installed roof curbs will reduce the...Ch. 50 - When rigging a unit to the roof, what minimum...Ch. 50 - What is the acceptable method for communicating...Ch. 50 - Prob. 9RQCh. 50 - Prob. 10RQ
Ch. 50 - The most efficient way to establish the best...Ch. 50 - Free-cooling can be accomplished if the
A....Ch. 50 - Prob. 13RQCh. 50 - Prob. 14RQCh. 50 - Explain why the outside air damper is typically...Ch. 50 - Briefly explain the purpose of ASHRAE Standard 62.Ch. 50 - Explain the concept of demand control ventilation.Ch. 50 - Explain how carbon dioxide levels can be used to...Ch. 50 - Describe the blowers used on VAV systems.Ch. 50 - A cooling-only VAV box has all of the following...Ch. 50 - Which of the following is true regarding a reheat...Ch. 50 - Variable refrigerant flow systems sense the...Ch. 50 - The acronym PID stands for ______, _____, and...Ch. 50 - Explain the main benefit of a heat-recovery VRF...Ch. 50 - The pump on a dry cooler can direct water to...Ch. 50 - During low ambient conditions, the space cooling...
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