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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Chapter 3, Problem 3.48P
Conditions in one zone of a dual-duct conditioning system are to be maintained at 75 F (24 C) and 50 percent relative humidity (RH). The cold deck air is at 52 F (11 C) and 90 percent RH, while the hot deck air is outdoor air at 90 F (32 C) and 20 percent RH. The sensible heat factor for the zone is 0.65. Assume sea-level pressure. In what proportion must the warm and cold air be mixed to satisfy the space condition? If the total zone load is 50 tons (176 kW), what is the total volume flow rate of air supplied to the zone? Sketch the states and processes on a psychrometric chart. Use (a) English units and (b) SI units.
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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...
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- notes : 1- Solve in British International Units, not in American units 2- Use operations and psychrometry in the solution as wellarrow_forwardAn 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 degrees celsius. Air enters the heating section at 10 degrees celsius and 70 percent relative humidity at a rate of 35 m^3/min, and it leaves the humidifying section at 20 degree celcius and 60 percent relative humidity. Heating coils Loooooooo 10°C 70% 35 m³/min AIR P = 1 atm Sat. vapor 100°C Humidifier € 20°C 60% a. Humidity ratio at inlet b. Relative humidity at the exit c. Humidity ratio at exit d. Rate at which water is added to humidifying sectionarrow_forwardplease solve in 5o mins i will give you positive feedback. i need handwritten solution on pagesarrow_forward
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