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 3.56P
One particular zone served by a multizone air handler has a design cooling load of 1750 Btu/hr (0.5 kW with a SHF of 0.8. The coil has air entering at 84 F (29 C) db and 70 F (21 C) wb with air leaving at 50 F (10 C) db and 90% relative humidity (RH). Zone conditions are 75 F (24 C) db and 50% RH. (a) What amount of air must be supplied to the space? (b) At what condition is the air supplied to the space? (c) How much air flows over the coil and how much air bypasses the coil for this one zone? Assume sea-level pressure.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
/ A hall is to be maintained at (20 °C DBT, 60 % RH) when the outdoor conditions are
(40 °C DBT, 26 °C WBT). With the following conditions:
Sensible heat load in the room
Latent heat load in the room
66000 kJ/hr
20000 kJ/hr
30 m/min
5 °C
Infiltrated air
Apparatus dew point temperature.
If the 60 % of the total air is recirculated from the hall and is mixed with the conditioned
air after the cooling coil. Find the following:
1-The conditions of air leaving the conditioner.
2- Mass of fresh air entering the cooler.
3- Bypass factor of the cooling coil.
4- The refrigeration capacity of the cooling coil in the tons of refrigeration
o 0a DDT
please solve in 4o mins i will give you positive feedback
Calculate the EER rating of a 20 ton (240000 Btu) air conditioning unit with an
average electrical load of 30 kW.
An air conditioning plant supplies air to a room at a rate of 2.5 kg/s, the supply
air being made up of equal parts by weight of outdoor and recirculated air. The
mixed air passes through a cooler coil fitted with a by-pass duct, face and by pass
dampers being used for humidity control. The air then passes through an after
heater and supply fan. In a test on the plant, the following conditions (Table Qu
4) were recorded;
3
Table Qu. 4: Parameters recorded
Relative humidity
Dry bulb
temperature
°C
Wet bulb
temperature
°C
%
Outdoor air
270
20.5
Room air
210
50
Supply air
Air leaving cooler
160
11.8
80
90
coil
Make neat sketches showing the plant arrangement and the psychrometric cycle and
identify the corresponding points on both diagrams.
Calculate the following;
mass of air through the cooler coil
load on cooler coil
load on heater
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
What parts are included in the vehicle chassis?
Automotive Technology: Principles, Diagnosis, And Service (6th Edition) (halderman Automotive Series)
The main waterline into a tall building has a pressure of 600kpa at 5m elevation below ground level. The buildi...
Fundamentals Of Thermodynamics
In each case, construct the parallelogram law to show FR = F1 + F2. Then establish the triangle rule, where FR ...
Statics and Mechanics of Materials (5th Edition)
Determine the minimum applied force P required to move wedge A to the right. The spring is compressed a distanc...
INTERNATIONAL EDITION---Engineering Mechanics: Statics, 14th edition (SI unit)
The onset of turbulence in a gas flowing within a circular tube occurs at ReD,c2300 , while a transition from i...
Fundamentals of Heat and Mass Transfer
ICA 8-20
A eutectic alloy of two metals contains the specific percentage of each metal that gives the lowest po...
Thinking Like an Engineer: An Active Learning Approach (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
- A summer air-conditioning shown below is required to maintain a certain room at specified conditions. The layout of the system is indicated on the next page and the specifications are listed below.System specifications:Required room temperature: 23⁰C, 50% Relative humidityAtmospheric pressure: 101 kPaOutside air conditions: 30⁰C, 80% Relative humidity Sensible heat gain: 5 kWLatent heat gain: 4 kWTemperature rise across fan: 1.5⁰CTemperature of air leaving cooler: 12⁰CTemperature of air entering room: 18⁰CApparatus dew point of cooler: 7⁰Carrow_forwardGaisano Mall uses an atmospheric cooling tower to provide cooling for the jacket water of a four-stroke 309 KW diesel generator. The cooling tower efficiency is 53% at a temperature of approach of 11 deg. C. if ambient air has a relative humidity of 60% and dry bulb temperature of 31 deg. C, determine the cooling water supplied to the diesel engine in liters/hour.arrow_forwardAir enters a coil in the air-handling unit (AHU) at dry-bulb temperature (Id) of 40 oC, and wet- bulb temperature (Tw) of 26 oC. The air leaves the coil at dry-bulb temperature (Td) of 12 oC, and relative humidity of 80%. This process is: Note: You need to use the psychrometric chart. O Cooling and humidification, and the air looses 50 kJ/kg of energy. O Heating and humidification and the air gains 110 kl/kg of energy. O Evaporative cooling and the air neither looses nor gains energy. O Cooling and dehumidification and the air looses 50 kl/kg of energy.arrow_forward
- An air-conditioning system to be installed in a factory with sensible and latent cooling loads of 175 KW and 65 KW, respectively. Assume that the relative humidity of supply air is 90%. The inside state is at 21 °C DB and 70% RH. What is the approximate required dry-bulb temperature in °C of the supply state of air? Select one: O a. 17 b. 16 O c. 18 O d. 14.5 Oe. 14 Larrow_forwardQ.2 An evaporative cooler is used to cool a space which has a sensible heat load of 15 kW and a latent heat load of 4.8 kW. The dry air mass flow rate of the supply air is 1.4 kg/s. The air leaves the cooler with a db-temperature of 18°C and a relative humidity of 100%. The outdoor air db-temperature is 35°C. The pressure is constant at 101.3 kPa. Determine (1) the db-temperature and relative humidity of the (ii) the outdoor relative humidity, and (iii) the mass flow rate of water. space,arrow_forwardUsing a psychometric diagram, describe the heating and humidification process from the following data. Initially the air was at dry bulb temperature (DBT) 35 ° C and RH 35%. air preheated to DBT 85 ° C. The heated air is then flowed through a humidifier to increase the RH to 25%. for this process, count, a. change in absolute humidity of air from initial to final conditions = ..... (kg water / kg air) b. change in air enthalpy from initial to final conditions = ..... (kj / kg air)arrow_forward
- าา 3.15.) In air conditioning unit, 71,000 cfm at 80'F dry bulb 60% th and standard atmospheric pressure, enter the unit. The air leaves the wait at 57°F dry bulb and 90% relative humidity. Calculate the following a.) Cooling capacity of the air conditioning unit, in Btu/h 6.) rate of water removal from the unit. (.) sensible heat load on the conditioner, in Btu/h di) latent heat load on the conditioning in Blu/h e.) The dew point of the air leaving the conditioner.arrow_forwardA summer air-conditioning shown below is required to maintain a certain room at specified conditions. The layout of the system is indicated on the next page and the specifications are listed below.System specifications:Required room temperature: 23⁰C, 50% Relative humidityAtmospheric pressure: 101 kPaOutside air conditions: 30⁰C, 80% Relative humiditySensible heat gain: 5 kWLatent heat gain: 4 kWTemperature rise across fan: 1.5⁰CTemperature of air leaving cooler: 12⁰CTemperature of air entering room: 18⁰CApparatus dew point of cooler: 7⁰C Draw the processes on a psychrometric chart and determine the following: 1.The ratio of mass flow rate of re-circulated air to the mass flow rate of air supplied to the room. 2.The heat removed by the cooling coil.3.The heat supplied in the re-heating coil. 4.The cooling coil bypass factor.arrow_forwardAir conditioning systemarrow_forward
- A space to be conditioned has a sensible heat load of 80 kw and a latent heat load of 20 kw and is to be maintained at 20°C and 50% relative humidity. Outside air is at 35°C and 60% RH. The conditioned air will enter the space at 15°C. If 40% of the supply air is fresh and the rest is recirculated, the refrigeration capacity of the system is nearest to what value? 430 kw 455 kw 428 kw Ⓒ333 kwarrow_forwardWhat happens when relative humidity (RH) = 100%? a)if the air is continued to be cooled, at what temperature will the saturation point be reached? b)What happens if the air is continued to be cooled below the DBT you just found? (psychrometric chart image)arrow_forwardPick 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 1.0arrow_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