# How to calculate : Mass flow of water vapor in the air (kg/h)

• Kristof Papp
In summary, the conversation discusses parameters such as air volume flow, relative humidity, air mixing ratio, and air temperature. The individual is looking for an equation to calculate the mass flow of the air's water content, but is unsure of how to use the given parameters and the density of water and dry air at a specific temperature. They also mention considering the density of an ideal gas mixture using mole fractions and the molar density of the mixture.
Kristof Papp
Hello

## Homework Statement

Lets say i have the given parameters:

air volume flow : V = 36 m3/h
Relative humidity: RH=33%
air mixing ratio : X = 5.5 (1g H2O) / 1kg (DRY AIR) (calculated from RH)
air temperature : T= 20 C

So i know how much mass of water is the air compared to the air's "dry air" mass content.

## Homework Equations

I only know the massflow's equation : m=ϱ*V , when the fluid consists of only 1 component.
But i don't know what to do, when the fluid constists of multiple components (H2o and Dry air).

So I know the air volume flow, but can't do anything with the density part, and don't know how to use "X"
, or the density of water and dry air at T=20

## The Attempt at a Solution

What is the equation which gives me the mass flow of the air's water content?
.

Thanks for help!

Do you know how to calculate the density of an ideal gas mixture, given the mole fractions (or mass fractions) of its components and the molar density of the mixture? What is the molar density of your gas mixture?

## 1. How is the mass flow of water vapor in the air calculated?

The mass flow of water vapor in the air is calculated using the following formula:
Mass Flow = Density of Water Vapor x Volume Flow Rate

## 2. What is the unit of measurement for mass flow of water vapor in the air?

The unit of measurement for mass flow of water vapor in the air is kilograms per hour (kg/h).

## 3. How is the density of water vapor in the air determined?

The density of water vapor in the air can be determined by using the ideal gas law:
Density = (Pressure x Molecular Weight) / (Gas Constant x Temperature)

## 4. What factors affect the mass flow of water vapor in the air?

The mass flow of water vapor in the air can be affected by factors such as temperature, pressure, and humidity. As temperature and pressure increase, the density of water vapor also increases, resulting in a higher mass flow. Humidity, on the other hand, affects the volume flow rate of water vapor in the air, which in turn affects the mass flow.

## 5. Can the mass flow of water vapor in the air be calculated for a specific location or time?

Yes, the mass flow of water vapor in the air can be calculated for a specific location and time. This requires accurate measurements of temperature, pressure, and humidity at that location and time, as well as an understanding of the volume flow rate of air in that location. These factors can vary greatly and can affect the accuracy of the calculated mass flow.

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