Heating Ventilating and Air Conditioning: Analysis and Design
6th Edition
ISBN: 9780471470151
Author: Faye C. McQuiston, Jeffrey D. Spitler, Jerald D. Parker
Publisher: Wiley, John & Sons, Incorporated
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 5, Problem 5.35P
A large beverage cooler resembles a small building and is to be maintained at about 35 F (2 C) and a low relative humidity. The walls and ceiling are well insulated and are finished on the inside with plywood. Assume that the outdoor temperature is generally higher than 35 F (2 C). In what direction will moisture tend to migrate? Where should the vapor retardant be located? Explain what might happen if the retardant is improperly located.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
During a hot summer day when the air temperature is 35°C and the relative humidity is 70 percent, you buy a supposedly “cold” canned drink from a store. The store owner claims that the temperature of the drink is below 10°C. Yet the drink does not feel so cold, and you are skeptical since you notice no condensation forming outside the can. Can the store owner be telling the truth?
A cooling duct receives air at 1 atm, 32°C, and 70% relative humidity with a velocity of 120m/min. This
air passes over cooling coils filled with flowing water. This steadily flowing water experiences a for
temperature rise during its time in the cooling duct coils. Meanwhile, the airflow leaves the cooling
section saturated at 20°C. Determine (a) the rate of heat transfer, (b) the mass flow rate of the cooling
water, (c) the flow rate of any condensate formed, and (d) the exit velocity of the air stream. Assume
the cooling water has constant specific heat. Feel free to use the psychrometric chart on the next page
for the air properties.
How much heat and moisture must be added to 8 cubic meter per minute of air at 17 C dry bulb and 35% relative humidity to raise it to 40 C and 45% relative humidity?
Show the psychometric chart diagram on your paper.
Chapter 5 Solutions
Heating Ventilating and Air Conditioning: Analysis and Design
Ch. 5 - Determine the thermal conductivity of 4 in. (100...Ch. 5 - Compute the unit conductance C for 512 in. (140...Ch. 5 - Compute the unit thermal resistance and the...Ch. 5 - What is the unit thermal resistance for an inside...Ch. 5 - Compute the thermal resistance per unit length for...Ch. 5 - Assuming that the blocks are not filled, compute...Ch. 5 - The partition of Problem 5-4 has still air on one...Ch. 5 - The pipe of Problem has water flowing inside with...Ch. 5 - Compute the overall thermal resistance of a wall...Ch. 5 - Compute the overall heat-transfer coefficient for...
Ch. 5 - Estimate what fraction of the heat transfer for a...Ch. 5 - Make a table similar to Table 5-4a showing...Ch. 5 - Estimate the unit thermal resistance for a...Ch. 5 - Refer to Problem 5-13, and estimate the unit...Ch. 5 - A ceiling space is formed by a large flat roof and...Ch. 5 - A wall is 20 ft (6.1 m) wide and 8 ft (2.4 m) high...Ch. 5 - Estimate the heat-transfer rate per square foot...Ch. 5 - A wall exactly like the one described in Table...Ch. 5 - Prob. 5.19PCh. 5 - Compute the overall heat-transfer coefficient for...Ch. 5 - Compute the overall heat transfer for a single...Ch. 5 - Determine the overall heattransfer coefficient for...Ch. 5 - A basement is 2020ft(66m) and 7 ft (2.13 m) below...Ch. 5 - Estimate the overall heat-transfer coefficient for...Ch. 5 - Rework Problem 5-23 assuming that the walls are...Ch. 5 - A heated building is built on a concrete slab with...Ch. 5 - A basement wall extends 6 ft (1.8 m) below grade...Ch. 5 - A 2440ft(7.312.2m) building has a full basement...Ch. 5 - The floor of the basement described in Problem...Ch. 5 - Assume that the ground temperature tg is 40 F (10...Ch. 5 - Use the temperatures given in Problem 5-30 and...Ch. 5 - A small office building is constructed with a...Ch. 5 - A 100 ft length of buried, uninsulated steel pipe...Ch. 5 - Estimate the heat loss from 100 m of buried...Ch. 5 - A large beverage cooler resembles a small building...Ch. 5 - Consider the wall section shown in Fig. 5-10. (a)...Ch. 5 - A building has floor plan dimensions of 3060ft....Ch. 5 - Compute the temperature of the metal roof deck of...Ch. 5 - Consider the wall section shown in Fig. -4a,...Ch. 5 - Consider the knee space shown in Fig. 5-11. The...Ch. 5 - Estimate the temperature in an unheated basement...
Additional Engineering Textbook Solutions
Find more solutions based on key concepts
The portable floor crane in the automotive shop is lifting a 420-lb engine. For the position shown compute the ...
Engineering Mechanics: Statics
Comprehension check 12-10
The preceding graph shows the ideal gas Jaw relationship (PV =nRT) between pressure (...
Thinking Like an Engineer: An Active Learning Approach (3rd Edition)
What are some of the process variables that must be specified when setting up an arc-welding process?
DeGarmo's Materials and Processes in Manufacturing
13.8 Calculate the shear and bending moment at 3 ft and at 8 ft from the left for the beams shown. Show free-bo...
Applied Statics and Strength of Materials (6th Edition)
Modified coefficient of performance and power input for clean condition.
Introduction to Heat Transfer
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- In an air sample with a dry-bulb temperature of 28°C and a wet-bulb temperature of 22°C what is the (relative humidity)?arrow_forwardHumid air at 25 oC and 80% relative humidity is cooled and dehumidified at atmospheric pressure, and then reheated and brought to 20 oC and 40% relative humidity. Analysis will be done by drawing on the psychometric diagram.a) What is the amount of water removed from the humid air (kg water / kg dry air)? b) What is the heat withdrawn from moist air (kJ / kgdry air)? c) What is the heat (kJ / kg dry air) given from the heater to the humid air?arrow_forward8. Moist air undergoes a heating and humidification process at a pressure of 101.325 kPa from an initial state of 15°C db and 90% relative humidity to a final state at 22°C and 70% relative humidity. If the mass flow rate of the air at the initial state is 24.5 kg da/s, what is the increase in the water content of the air? Express your answer in kg/s. In your written solution, draw the process in the psychrometric chart, show the initial and final state and the values obtained from the chart.arrow_forward
- Consider two rooms that are identical except that one is maintained at 25°C and 40 percent relative humidity while the other is maintained at 20°C and 55 percent relative humidity. Noting that the amount of moisture is proportional to the vapor pressure, determine which room contains more moisture.arrow_forwardThe air in a house are at a total pressure of 100 kPa and 28°C DB. The surface temperature of a window of the house is 12°C. What is the maximum relative humidity (in %) allowable in the house if no condensation is to occur on the surface of the window?arrow_forwardOn a certain day, the temperature is 25.0ºC and the relative humidity is 90.0%. How many grams of water must condense out of each cubic meter of air if the temperature falls to 15.0ºC ? Such a drop in temperature can, thus,produce heavy dew or fog.arrow_forward
- A dehumidifier brings in saturated wet air (100 percent relative humidity) at 30°C and 1 atm, through an inlet of 8-cm diameter and average velocity 3 m/s. After some of the water vapor condenses and is drained off at the bottom, the somewhat drier air leaves at approximately 30°C, 1 atm, and 50 percent relative humidity. For steady operation, estimate the amount of water drained off in kg/h. (This problem is idealized from a real dehumidifier.) (in kg/hr) Note: Use three decimal places and no need to input the unit.arrow_forward12 bales of cotton, each weighing 486 lb, were held for conditioning in a humid warehouse kept at a relative humidity of 95%. Calculate the total mass of water, in lb, held within these bales at the end of the conditioning period.arrow_forwardHumid air at 25 °C and 80% relative humidity is cooled and dehumidified at atmospheric pressure, and then reheated and brought to 20 °C and 40% relative humidity. Analysis will be done by drawing on the psychometric diagram. a) What is the amount of water (kg/kgimnhavn) removed from the humid air? b) What is the heat extracted from moist air (kJ/kgkuair)? c) What is the heat (kJ/kgumair) given from the heater to the humid air?arrow_forward
- An air-conditioning system operates at a total pressure of one atmosphere and consists of a heating section and an evaporative cooler. Air enters the heating section at 10 °C and 70 percent relative humidity at a rate of 30 m3/min, and it leaves the evaporative cooler at 20 °C and 60 percent relative humidity. Use this information to answer the following question. Choose the nearest value given in (a) – (e).The rate of water added to air in the evaporative cooler (kg/min) is (a) 0.12 (b) 0.67 (c) 13 (d) 37 (e) 67arrow_forwardAir enters the heating section of an air-conditioning at 1atm, 10C, and 70 percent relative humidity at a rate of 35m^3/min, and it leaves the humidifying section at 20C with a relative humidity of 90 percent. If the humidifier supplies wet steam at 100C, determine: The temperature and relative humidity of the air leaving the heating section The rate of heat transfer in the heating sectionarrow_forwardUsing the skew-t diagram, calculate the relative humidity for two air parcels at two different pressure levels: At 1000 hPa that has a temperature of 25C and a mixing ratio of 16 g/kg. At 700 hPa that has a dew point temperature of -10C and a saturation mixing ratio of 12 g/kg. show your work on the skew-t diagram by drawing the lines to find the values OR explain the steps to find the value. Then, use those numbers to calculate relative humidity.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY
Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education
Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY
The Refrigeration Cycle Explained - The Four Major Components; Author: HVAC Know It All;https://www.youtube.com/watch?v=zfciSvOZDUY;License: Standard YouTube License, CC-BY