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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
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Textbook Question
Chapter 4, Problem 4.14P
To save energy in large, chilled water systems, the water temperature delivered to the cooling coils can be increased. A larger quantity of warmer supply air can remove the same energy from a space as a smaller quantity of cooler air. What could happen to the humidity of the space? Are there times during a daily cycle when the humidity load of certain spaces might be greatly reduced? Discuss.
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An air-conditioning system operates at a total pressure of 1 atm and consists of a
heating section and a humidifier that supplies wet steam (saturated water vapor) at
100°C. Air enters the heating section at 10°C and 70 percent relative humidity at a rate
of 32 m /min, and it leaves the humidifying section at 20°C and 60 percent relative
humidity. Use data from the tables.
Sat. vapor
100°C
Heating
coils
Humidifier
10°C
Air
20°C
70%
60%
ymYmin
P=1 atm
Determine the temperature and relative humidity of air when leaves the heating section.
The temperature is
°C.
The relative humidity is
%.
The cooling load calculations on a theatre show that at design conditions the sensible heat load is 200 kw and the latent heat load is 70 kw. The indoor design conditions are 26°C dry bulb and50% relative humidity. Air is to be supplied to the theatre at 16°C while the outside airis at 30°C dry bulb and 60% relative humidity. Take ventilating air as 25% of the supply air. Calculate the tons of refrigeration required by the conditioner.
Read the question carefully. Don't miss any calculations.
The recycled duct air in a centralized air conditioning system takes in air at a rate of 60 m3/min with a dry bulb temperature of 20 oC and 30% relative humidity. The recycled air is mixed adiabatically with fresh outdoor air at a rate of 80 m3/min with a dry bulb temperature of 30 oC and 50% relative humidity. Calculate the volumetric flow rate, dry bulb temperature and relative humidity of the mixed air stream. Use the psychrometric chart to get property data and plot the process on the psychrometric chart.
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...
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