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 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.
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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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- Air (mass of dry air: 3 kg) with a relative humidity of 50% at 25 °C is supplied isobaric 30 kJ. What is the relative humidity after that?arrow_forwardInside a building, the temperature is 5\deg C, and the relative humidity is 43 percent. How much water vapor ( in kg) is there in each cubic meter of air? answer in kgarrow_forwardA quantity of moist air of mass 4 kg has a humidity ratio of 0.019 and a relative humidity of 65%. The pressure is 95 kPa. -What is the dry-bulb temperature in °C?-What is the volume of the air sample in m^3?-What is the dew-point temperature in °C?-What is the enthalpy in kJ/kg?arrow_forward
- Air is heated and humidified in air conditioning process. Mist humidifier is used. The mass flow rate of inlet air is 20 kg/s, temperature -5 °C and relative humidity 40 %. After heating, the temperature of air is 30 °C. After mist humidifier, the relative humidity of air is 70 %. Calculate or look up from Mollier chart: 1) Enthalpy of inlet air 2) Absolute humidity of inlet air 3) Enthalpy of heated air 4) Relative humidity of heated air 5) Absolute humidity of heated air 6) Heating power kJ/kg (with one decimal accuracy) g/kgdry air (with one decimal accuracy) kJ/kg (with one decimal accuracy) % (with zero decimal accuracy) g/kgdry air (with one decimal accuracy) KW (with zero decimal accuracy) 7) Absolute humidity after humidifier 8) Mass flow rate of the humidifier mist 9) Temperature after humidifier 10) Enthalpy after humidifier g/kgdry air (with one decimal accuracy) kg/s (with three decimal accuracy) °C (with one decimal accuracy) kJ/kg (with one decimal accuracy)arrow_forwardA moist air sample has dry bulb temperature of 30°C and specific humidity of 11.5 g water vapour per kg dry air Assume molecular weight of air as 28.93 . If the saturation vapour pressure of water at 30°C is 4.24 kPa and the total pressure is 90 kPa, then the relative humidity (in %) of air sample is, (a) 50.5 (b) 38.5 (c) 56.5 (d) 68.5arrow_forwardPlease show workings. Thankyou.arrow_forward
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