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
Concept explainers
Videos
Textbook Question
Chapter 4, Problem 4.11P
Discuss how an emergency government mandate to set all thermostats at 65 F (18 C) for wintertime heating would affect the following classes of people: (a) a person dressed in a business suit and vest, (b) a typist who basically sits all day, (c) a worker on an automobile assembly line, (d) a clerk in a grocery store, and (e) a patient in a doctor’s examination room clothed in a gown.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Most houses have vents that open and close manually without any central control.Cities across the United States advise the use of such vents in an effort to saveenergy. In most cases, household occupants do not use the entire house at the sametime; the tendency is to use certain rooms for long periods of time. For example,the family room and dining room may be used heavily, while the living room andkitchen are used at certain hours of the day. To cool or heat a room, the vent systemmust work to cool or heat the entire house. Energy saving can be enhanced if thevents of unused rooms are closed; this will push the hot/cold air to where it isneeded most and reduce the load of the conditioning system. Develop an objectivetree to clarify the need statement and prioritize the objectives laid out in the problem statement. You may add features that may not be listed clearly in the problemstatement but will give an additional advantage to the proposed design.
11. Five large hotels in Miami, USA, use their own air-conditioning units, which
have a c.o.p. 3.1. It is proposed that the cooling systems of the five hotels be
substituted with a larger, modern unit that would have a c.o.p. 3.7. The total
installed capacity of the five hotels is 2,600 tons of air-conditioning and the
current systems are in use for 3,200 hours every year. Determine: a) the annual
energy savings from this substitution and b) the annual avoidance of CO₂
emissions if, currently, 72% of the electric energy in the Miami area is
obtained from coal power plants and 28% from nuclear power plants.
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 4 Solutions
Heating Ventilating and Air Conditioning: Analysis and Design
Ch. 4 - Using Fig. 4-1, draw a conclusion about the...Ch. 4 - Using Fig. 4-1, draw a conclusion about the...Ch. 4 - Select comfortable summer design conditions (dry...Ch. 4 - It is desired to use a space as a large classroom...Ch. 4 - An indoor tennis facility finds that it has...Ch. 4 - Work Problem 4-5 for an average air speed at court...Ch. 4 - In an occupied space the mean air velocity is...Ch. 4 - An occupied space is being held at 76 F (24 C) and...Ch. 4 - What do you think is the best thermostat setting...Ch. 4 - With the air conditioning running and the...
Ch. 4 - Discuss how an emergency government mandate to set...Ch. 4 - In the heating seasons the heat loss from a...Ch. 4 - Air motion can be good or bad, depending on the...Ch. 4 - To save energy in large, chilled water systems,...Ch. 4 - Overhead fans (Casablanca fans) are often reversed...Ch. 4 - A school classroom is designed for 30 people. (a)...Ch. 4 - Carbon dioxide is being generated in an occupied...Ch. 4 - Each person in a room is assumed to be producing...Ch. 4 - An air-handling system must handle 2000 cfm with a...Ch. 4 - Prob. 4.20PCh. 4 - How many filter modules will be required using the...Ch. 4 - Work Problem 4-21 assuming that the filter is a...Ch. 4 - The M-200, 0.60.60.2 filters of Table 4-3 are to...Ch. 4 - Investigate the feasibility of using 100 percent...Ch. 4 - Work Problem 4-24 but replace the 100 percent...Ch. 4 - Using M-15 filter media and the requirement of 60...Ch. 4 - A filter system is available that will filter out...Ch. 4 - A maximum of 10 smokers are anticipated in a smong...Ch. 4 - Solve Ex. 4-4 assuming that the filter is in...Ch. 4 - Solve Problem 4-28 assuming that the filter is in...Ch. 4 - Fora 3000-ft3 combination and exercise operation,...Ch. 4 - A classroom with a capacity of 225 people is...
Additional Engineering Textbook Solutions
Find more solutions based on key concepts
Describe the structural changes that take place when a plain-carbon eutectoid steel is slowly cooled from the a...
Foundations of Materials Science and Engineering
17–1C A high-speed aircraft is cruising in still air. How does the temperature of air at the nose of the aircra...
Thermodynamics: An Engineering Approach
Locate the centroid of the area. Prob. 9-17
Engineering Mechanics: Statics
Select a mechanical component from Part 3 of this book (roller bearings, springs, etc.), go to the Internet, an...
Shigley's Mechanical Engineering Design (McGraw-Hill Series in Mechanical Engineering)
23.23 A highly oxidized and uneven round bar is being turned on a lathe. Would you recommend a small or a large...
Manufacturing Engineering & Technology
A pipe flowing light oil has a manometer attached, as shown in Fig, P1.52. What is the absolute pressure in pip...
Fundamentals Of Thermodynamics
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
- An increase in the natural greenhouse effect that leads to heating of the earth is called _____.arrow_forwardWhat is the heat output, in Btu/h, of a terminal unit with a T of 10F and a water flow rate of 5 gpm?arrow_forwardIf we wanted to supply a world of 10 billion people with an average demand of electricity at 1 kW per person, what surface area of photovoltaic arrays would be required? Compare this to the size of a known city, state or country.arrow_forward
- energy can be conserved when your home heating/cooling system works less during the heating and cooling seasons. in fact/ a one degree celsius difference in your thermostat setting can reduce energy consumption by up to 5%arrow_forwardQUESTION TWO (a) Consider the process of heating water on top of an electric range.i. What are the forms of energy involved during this process?ii. What are the energy transformations that take place?(b) A classroom that normally contains 40 people is to be air-conditioned with window air-conditioning units of 5-kW cooling capacity. A person at rest may be assumed to dissipate heat at a rate of about 360 kJ/h. There are 10 light bulbs in the room, each with a rating of 100 W. The rate of heat transfer to the classroom through the walls and the windows is estimated to be 15,000 kJ/h. If the room air is to be maintained at a constant temperature of 21°C, determine the number of window air-conditioning unitsrequired.(c) Consider two closed systems A and B. System A contains 3000 kJ of thermal energy at 20°C, whereas system B contains 200 kJ of thermal energy at 50°C. Now the systems are brought into contact with each other. Determine the direction of any heat transfer between the two…arrow_forwardAn air-cooled window DX unit is used for space cooling. The unit has a capacity of 4.5 tons and has a SEER of 15. If the unit operates for 2204 hours during the summer, how many kWh of electricity will be used? Hint: In the U.S., the SEER is the ratio of cooling in British thermal units (BTUs) to the electrical energy consumed in watt-hours. You may need to convert the unit in this process.arrow_forward
- Which of the following will be useful for modelling the process in an air conditioning unit O No-flow Energy Equation O Steady Flow Energy Equation O Fourier's Law O Newton's law of coolingarrow_forward13 .Mexico's metro requires the implementation of an air conditioning system for each of its cars. On the hottest days the air inside the car can reach 45°C. A temperature of 25°C is expected to be achieved to keep passengers satisfied. A car measures 17 m x 2.5 x 2. In order to make the decision on the air conditioning system to install, the engineering director has asked to calculate: A. Amount of energy to be removed from the car when the air is at 45°C and the car is empty. B. Amount of energy to withdraw when the car is full (approx. 130 people with a volume of 0.06 m3/person). Each person releases 30 kJ while in the car. C. Power of a system that removes the estimated energy A and B in less than 1 minute.arrow_forwardHow can a solar dish be used to produced electricity? O a. Connect to a stirling engine and a generator O b. Put solar cells О с. Connect to the grid O d. Connect to a batteryarrow_forward
- List all the desirable properties of a refrigerant for an air conditioning system and explain the importance of each property to the functioning of the air conditioning system.arrow_forwardAssume that the average solar insolation in Jamaica is 6500Wh/m² per day and its land area is 10,992 km². Consider that 3% of the land area could be covered by photovoltaic (PV) solar farms and 80% of the area of the solar farm is covered with PV modules with a conversion efficiency of 20%. In this case how much energy expressed in kWh/day could be produced using PV farms? Part B With the aid of diagrams, explain the similarities and differences between a fuel fired steam plant and a combined cycle gas plant. Label all major sections of your diagrams. With the aid of a simple sketch, explain how the following angles affect the location of the sun relative to the earth's sky. • Solar declination Solar azimuth Altitude 1arrow_forwardWrite systematically how is solar thermal energy captured using solar power towers? Explain with a suitable diagram.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...
Mechanical Engineering
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:Cengage Learning
Hydronics Step by Step; Author: Taco Comfort Solutions;https://www.youtube.com/watch?v=-XGNl9kppR8;License: Standard Youtube License