Question

How would I convert relative humidity to specific humidity? The variables I have are vapor pressure,...

How would I convert relative humidity to specific humidity? The variables I have are vapor pressure, air temperature, and relative humidity.

Homework Answers

Answer #1

We know that

Relative humidity can be defined as the ratio of vapour pressure of water (at a temperature and pressure) to the vapour pressure of gas over water φ = pw / pws 100%

specific humidity can be defined as the ratio of the mass of water vapor in air to the total mass of the air ans water vapour xs = 0.622 pws / (pa - pws)   

Where

φ = relative humidity

xs = specific humidity of air vapor mixture (kg/kg)

ρws = density of water vapor

ρ = density of the moist or humid air

we have air temperature , vapour pressure and relative humidity

φ = pw / pws

xs = 0.62 pws / (pa - pws)   

so on rearranging we may say that

xs = 0.62 φ ρws / (ρ - ρws)

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The relative humidity of air equals the ratio of the partial pressure of water in the...
The relative humidity of air equals the ratio of the partial pressure of water in the air to the equilibrium vapor pressure of water at the same temperature times 100%. If the relative humidity of the air is 58% and its temperature is 68 oF , how many moles of water are present in a room measuring 12 ft x 10 ft x 8 ft? The vapor pressure of water at 68 oF is 17.54 torr. The answer is 20,...
What is the dew point (the temperature at which 100% relative humidity would occur) on a...
What is the dew point (the temperature at which 100% relative humidity would occur) on a day when relative humidity is 23.0% at a temperature of 25°C? (Assume that the saturation vapor density increases linearly from 0°C to 5°C.)
On a hot summer day in Washington, D.C., the temperature is 104°F, and the relative humidity...
On a hot summer day in Washington, D.C., the temperature is 104°F, and the relative humidity is 78%. How much water vapor does each cubic meter of air contain? ______kg
a) calculate the percent relative humidity when temperature is at 30 degree Celsius and air contain...
a) calculate the percent relative humidity when temperature is at 30 degree Celsius and air contain 10 gram of water vapor per cubic meters. b) calculate the percent relative humidity when the temperature is at 30 degree Celsius and dew point is at 5 degree Celsius.
Atmosphric air at 40 F and 50% relative humidity enters the heating section of an airconditioning...
Atmosphric air at 40 F and 50% relative humidity enters the heating section of an airconditioning device at a volumetric flow rate of 100ft^3/min. Water vapor is added to the heated air to increase the relative humidity to 55%. The temperature after the heating section is 72F and the temperature at the exit is 74F. Using the appropriate fomulas: a) determine the rate of the heat transfer in Btu/min. b) determine the mass flow of water vapor in lbm/min.
Consider atmospheric conditions as follows: temperature of 30 C, normal atmospheric pressure and a humidity of...
Consider atmospheric conditions as follows: temperature of 30 C, normal atmospheric pressure and a humidity of 80%. A) What is the moisture content of the air? B) What is the partial pressure of water vapor in the atmosphere?
Thermodynamics Problem 12.85 Imagine a 2000 ft^(3) of an air-water vapor mixture at 14.7 psi, 90...
Thermodynamics Problem 12.85 Imagine a 2000 ft^(3) of an air-water vapor mixture at 14.7 psi, 90 Fahrenheit, 70 % relative humidity. Calculate the: A. Humidity Ratio B. Dew Point in Fahrenheit C.Mass of Air D. Mass of Vapor E. Saturated Pressure for the water vapor in the mixture. F. Vapor Pressure G. Partial Pressure for Dry Air H. Mass of dry air I. Pressure for the water vapor leaving the duct in psi J. Entalphy of saturated Vapor in BTU/lbm
In a condenser, humid air at atmospheric pressure, 35 degree celsius and 90% relative humidity enters...
In a condenser, humid air at atmospheric pressure, 35 degree celsius and 90% relative humidity enters the process at a rate of 2.12 m3/s. Liquid water exits as a condensate. If the air exits at 20 degree celsius, determine the molal humidity of outlet air, absolute humidities of inlet and outlet air and flow rate of condensate in L/s.
Air at 45O​C (dry bulb) and 10% relative humidity is to be humidified adiabatically to 70%...
Air at 45O​C (dry bulb) and 10% relative humidity is to be humidified adiabatically to 70% relative humidity. (a) Use the psychrometric chart to estimate the adiabatic saturation temperature of the air. (b) Estimate the final temperature of the air and the rate at which water must be added to humidify 15 kg/min of the entering air. (c) What have you assumed in carrying out this calculation?
Moist air at 30 °C and 50% relative humidity enters a dehumidifier operating at steady state...
Moist air at 30 °C and 50% relative humidity enters a dehumidifier operating at steady state with a mass flow rate of 319.35 kg/min. The moist air passes over a cooling coil and water vapor condenses. Condensate (condensed water) exits at 10 °C. Saturated moist air exits in a separate stream at the same temperature. The pressure remains constant at 1 bar. Determine (a) the rate at which water is condensed, in kg/min, and (b) the heat transfer rate during...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT