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
Videos
Textbook Question
Chapter 3, Problem 3.12P
Conditions in a room are measured to be 80 F db and 65 F wb, respectively. Compute the humidity ratio and relative humidity for the air at (a) sea levelland (b) 5000 ft.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Explain why on the interval 0<x<1000 mm and 1000<x<2000mm, Mt is equal to positive 160 Nm, but at x= 0mm and x=1000mm Mt is equal to -160 Nm (negative value!). What is the reason for the sign change of Mt?
20
3.
2-233
2520
Тр
Gears
1079
A pair of helical gears consist of a 20 teeth pinion meshing with a 100 teeth gear. The pinion rotates at
Ta
720 r.p.m. The normal pressure angle is 20° while the helix angle is 25°. The face width is 40 mm and
the normal module is 4 mm. The pinion as well as gear are made of steel having ultimate strength of
600 MPa and heat treated to a surface hardness of 300 B.H.N. The service factor and factor of safety
are 1.5 and 2 respectively. Assume that the velocity factor accounts for the dynamic load and calculate
the power transmitting capacity of the gears.
[Ans. 8.6 kW
4. A single stage helical gear reducer is to receive power from a 1440 r.p.m., 25 kW induction motor. The
gear tooth profile is involute full depth with 20° normal pressure angle. The helix angle is 23°,
number of teeth on pinion is 20 and the gear ratio is 3. Both the gears are made of steel with allowable
beam stress of 90 MPa and hardness 250 B.H.N.
(a) Design the gears for 20% overload carrying capacity from standpoint of bending strength and
wear,
(b) If the incremental dynamic load of 8 kN is estimated in tangential plane, what will be the safe
power transmitted by the pair at the same speed?
Chapter 3 Solutions
Heating Ventilating and Air Conditioning: Analysis and Design
Ch. 3 - A space is at a temperature of 75 F (24 C), and...Ch. 3 - Determine the humidity ratio, enthalpy, and...Ch. 3 - Suppose the air of Problem 3-2 is at a pressure...Ch. 3 - What is the enthalpy of moist air at 70 F (20 C)...Ch. 3 - The inside surface temperature of a window in a...Ch. 3 - What is the mass flow rate of dry air flowing at a...Ch. 3 - Determine the dew point of moist air at 80 F (27...Ch. 3 - A room is to be maintained at 72 F (22 C) db. It...Ch. 3 - Air is cooled from 80 F db and 67 F wb until it is...Ch. 3 - Conditions in a room are measured to be 80 F db...
Ch. 3 - The environmental conditions in a room are to be...Ch. 3 - Air enters a cooling coil at the rate of 5000 cfm...Ch. 3 - Air flowing in a duct has dry and wet bulb...Ch. 3 - Air is humidified with the dry bulb temperature...Ch. 3 - Air at 38 C db and 20 C wb is humidified...Ch. 3 - Two thousand cfm (1.0 m3/s) of air at an initial...Ch. 3 - Air at 40 F (5 C) db and 35 F (2 C) wb is mixed...Ch. 3 - Rework Problem 3-25, using Chart 1a, with the...Ch. 3 - The design cooling load for a zone in a building...Ch. 3 - Assume that the air in Problem 3-22 is supplied to...Ch. 3 - The sensible heat loss from a space is 500,000...Ch. 3 - Air enters a refrigeration coil at 90 Fdb and 75...Ch. 3 - A building has a total heating load of 200,000...Ch. 3 - Reconsider Problem 3-36 for an elevation of 5000...Ch. 3 - The system of Problem 3-34 has a supply air fan...Ch. 3 - An evaporative cooling system is to be used to...Ch. 3 - A cooling system is being designed for use at high...Ch. 3 - Consider a space heating system designed as shown...Ch. 3 - A variable-air-volume VAV cooling system is a type...Ch. 3 - Rework Problem 3-43 for an elevation of 5000 feet...Ch. 3 - The design condition for a space is 77 F (25 C) db...Ch. 3 - Rework Problem 3-45 for an elevation of 5000 feet...Ch. 3 - It is necessary to cool and dehumidify air from 80...Ch. 3 - Conditions in one zone of a dual-duct conditioning...Ch. 3 - Rework Problem 3-48 for an elevation of 5000 ft...Ch. 3 - A water coil in Problem 3-48 cools return air to...Ch. 3 - A multizone air handler provides air to several...Ch. 3 - Under normal operating conditions a zone has a...Ch. 3 - An interior zone of a large building is designed...Ch. 3 - Outdoor air is mixed with room return air to...Ch. 3 - Consider an enclosed swimming pool. The pool area...Ch. 3 - One particular zone served by a multizone air...Ch. 3 - A research building requires 100 percent outdoor...Ch. 3 - A space requires cooling in the amount of 120,000...
Additional Engineering Textbook Solutions
Find more solutions based on key concepts
27. A “normal” blood pressure has a gauge pressure of 120 millimeters of mercury [mm Hg] (systolic reading) ove...
Thinking Like an Engineer: An Active Learning Approach (4th Edition)
Determine the maximum force P that can be applied without causing movement of the 250-lb crate that has a cente...
INTERNATIONAL EDITION---Engineering Mechanics: Statics, 14th edition (SI unit)
Big data Big data describes datasets with huge volumes that are beyond the ability of typical database manageme...
Management Information Systems: Managing The Digital Firm (16th Edition)
What output will be produced by the following code? public class Demo { public static void main (String[] args)...
Java: An Introduction to Problem Solving and Programming (8th Edition)
Describe the weld pool geometry and size of the heat-affected zone in laser-beam welding.
Degarmo's Materials And Processes In Manufacturing
What will the following program display? def main (): x = 1 y = 3.4 print(x, y) change_us(x, y) print(x, y) def...
Starting Out with Python (4th Edition)
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
- Determine the stress in each section of the bar shown in Fig. when subjected to an axial tensile load shown in Fig. The central section is 30 mm hollow square cross- section; the other portions are of circular section, their diameters being indicated What will be the total deformation of the bar? For the bar material E = 210GPa. 20mi О 30mm 30mmm 2.6 15mm 30kN 1 2 10kN - 20kN 3 -329 91mm 100mm 371mmarrow_forwardCalculate the load that will make point A move to the left by 6mm, E=228GPa. The diameters of the rods are as shown in fig. below. 2P- PA 80mm B 200mm 2P 0.9m 1.3m.arrow_forwardIf the rods are made from a square section with the dimension as shown. Calculate the load that will make point A move to the left by 6mm, E=228GPa. 2P- P A 80mm B 200mm 2P 0.9m 1.3marrow_forward
- 3. 9. 10. The centrifugal tension in belts (a) increases power transmitted (b) decreases power transmitted (c) have no effect on the power transmitted (d) increases power transmitted upto a certain speed and then decreases When the belt is stationary, it is subjected to some tension, known as initial tension. The value of this tension is equal to the (a) tension in the tight side of the belt (b) tension in the slack side of the belt (c) sum of the tensions in the tight side and slack side of the belt (d) average tension of the tight side and slack side of the belt The relation between the pitch of the chain (p) and pitch circle diameter of the sprocket (d) is given by 60° (a) p=d sin (c) p=d sin (120° T where T Number of teeth on the sprocket. 90° (b) p=d sin T 180° (d) p=d sin Tarrow_forwardOBJECTIVE TYPE QUESTIONS 1. The maximum fluctuation of energy is the 2. (a) sum of maximum and minimum energies (b) difference between the maximum and minimum energies (c) ratio of the maximum energy and minimum energy (d) ratio of the mean resisting torque to the work done per cycle In a turning moment diagram, the variations of energy above and below the mean resisting torque line is called (a) fluctuation of energy (b) maximum fluctuation of energy (c) coefficient of fluctuation of energy (d) none of the above Chapter 16: Turning Moment Diagrams and Flywheel 611 The ratio of the maximum fluctuation of speed to the mean speed is called 3. (a) fluctuation of speed (c) coefficient of fluctuation of speed 4. (b) maximum fluctuation of speed (a) none of these The ratio of the maximum fluctuation of energy to the.......... is called coefficient of fluctuation of energy. (a) minimum fluctuation of energy (b) work done per cycle The maximum fluctuation of energy in a flywheel is equal to 5.…arrow_forwardOBJECTIVE TYPE QUESTIONS 1. The velocity ratio of two pulleys connected by an open belt or crossed belt is 2. (a) directly proportional to their diameters (b) inversely proportional to their diameters (c) directly proportional to the square of their diameters (d) inversely proportional to the square of their diameters Two pulleys of diameters d, and d, and at distance x apart are connected by means of an open belt drive. The length of the belt is (a)(d+d₁)+2x+ (d₁+d₂)² 4x (b)(d₁-d₂)+2x+ (d₁-d₂)² 4x (c)(d₁+d₂)+ +2x+ (d₁-d₂)² 4x (d)(d-d₂)+2x+ (d₁ +d₂)² 4x 3. In a cone pulley, if the sum of radii of the pulleys on the driving and driven shafts is constant, then (a) open belt drive is recommended (b) cross belt drive is recommended (c) both open belt drive and cross belt drive are recommended (d) the drive is recommended depending upon the torque transmitted Due to slip of the belt, the velocity ratio of the belt drive 4. (a) decreases 5. (b) increases (c) does not change When two pulleys…arrow_forward
- Q3: (10 MARKS) A piston with a weight of 29.4 N is supported by a spring and dashpot. A dashpot of damping coefficient c = 275 N.s/m acts in parallel with the spring of stiffness k = 2400 N/m. A fluctuating pressure p = 960 sin 30t N/m² acts on the piston, whose top surface area is 0.05 m². Determine the steady-state displacement as a function of time and the maximum force transmitted to the base. P=Po sin cot Warrow_forward9. Design a spur gear drive required to transmit 45 kW at a pinion speed of 800 r.p.m. The velocity ratio is 3.5 : 1. The teeth are 20° full-depth involute with 18 teeth on the pinion. Both the pinion and gear are made of steel with a maximum safe static stress of 180 MPa. Assume a safe stress of 40 MPa for the material of the shaft and key. 10. Design a pair of spur gears with stub teeth to transmit 55 kW from a 175 mm pinion running at 2500 r.p.m. to a gear running at 1500 r.p.m. Both the gears are made of steel having B.H.N. 260. Approximate the pitch by means of Lewis equation and then adjust the dimensions to keep within the limits set by the dynamic load and wear equation.arrow_forward7. A motor shaft rotating at 1440 r.p.m. has to transmit 15 kW to a low speed shaft rotating at 500 r.p.m. The teeth are 20° involute with 25 teeth on the pinion. Both the pinion and gear are made of cast iron with a maximum safe stress of 56 MPa. A safe stress of 35 MPa may be taken for the shaft on which the gear is mounted. Design and sketch the spur gear drive to suit the above conditions. The starting torque may be assumed as 1,25 times the running torque. Ruins 20 LW at 100 nm to another shaft running approxiarrow_forward
- 6. A two stage reduction drive is to be designed to transmit 2 kW; the input speed being 960 r.p.m. and overall reduction ratio being 9. The drive consists of straight tooth spur gears only, the shafts being spaced 200 mm apart, the input and output shafts being co-axial.arrow_forward2 A metal block of mass m = 10 kg is sliding along a frictionless surface with an initial speed Vo, as indicated below. The block then slides above an electromagnetic brake that applies a force FEB to the block, opposing its motion. The magnitude of the electromagnetic force varies quadratically with the distance moved along the brake (x): 10 FEB = kx², with k = 5 N m² V₁ = 8 m/s m = 10 kg FEB Frictionless surface Electromagnetic brake ⇒x Determine how far the block slides along the electromagnetic brake before stopping, in m.arrow_forwardQ1: Determine the length, angle of contact, and width of a 9.75 mm thick leather belt required to transmit 15 kW from a motor running at 900 r.p.m. The diameter of the driving pulley of the motor is 300 mm. The driven pulley runs at 300 r.p.m. and the distance between the centers of two pulleys is 3 meters. The density of the leather is 1000 kg/m³. The maximum allowable stress in the leather is 2.5 MPa. The coefficient of friction between the leather and pulley is 0.3. Assume open belt drive.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 Press
Mechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSON
Thermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEY
Mechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage Learning
Engineering 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