Hello everyone, I have a question about calculating Relative humidity. If I have a surrounding with 30 degrees Celsius and RH of 30%. I am cooling the surrounding with an air conditioner that works at 15 degrees Celcius. At the end of the process, the room reaches 25 degrees Celcius. In this situation, there is no condensation in the process. How can I calculate what is the RH at the end of the process? Thank you very much
top of page
To see this working, head to your live site.
Comments (1)
Commenting on this post isn't available anymore. Contact the site owner for more info.
Thermodynamics Misconceptions Exposed
As engineers, our world revolves around the fundamental laws that govern energy and its transformations. Thermodynamics, the backbone of...
Thermodynamics Forum
2 min read
Unlocking the Secrets of Thermodynamics: A Beginner's Guide
Welcome, aspiring scientists and engineers! Today, we're delving into the fascinating world of thermodynamics, where heat, energy, and...
Thermodynamics Forum
2 min read
Best online resources to study Thermodynamics, Fluid Mechanics, and Heat Transfer
I have been researching about best reference books, best lecture series, and best universities to study thermal sciences since I was in...
Thermodynamics Forum
2 min read
Approximate Values of Heat Transfer Coefficient
The higher the value of heat transfer the faster will be the heat transfer according to Newton's law of cooling.
Thermodynamics Forum
1 min read
Volumetric Flow Rate - 5W1H
It is a measure of the quantity of the fluid that is being displaced from one place to other.
This is an important parameter when designing
Thermodynamics Forum
1 min read
Throttling Process
The pressure drop in the thermal system can be obtained by expanding the fluid in the expansion valve which produces thermodynamic work.
Thermodynamics Forum
4 min read
Path Function vs Point Function
We come across a lot of properties and functions in Thermodynamics. These are divided mainly into path functions and point functions. All...
Thermodynamics Forum
3 min read
The Carnot Principles
The efficiency of an irreversible heat engine is always less than the efficiency of a reversible engine operating between the same two
Thermodynamics Forum
2 min read
Temperature-Entropy(T-s) Diagram
The T-s diagram is one of the most used plots in Thermodynamics. It is used to analyze vapor power cycles, gas power cycles, and
Thermodynamics Forum
3 min read
bottom of page
Hi, welcome to the Thermodynamics Forum :)
For this problem,
are you assuming that the air coming at 15 C from air conditioning does not add more moisture into the system?
If YES then,
this problem can be easily solved as follows:
By using the given RH1 = 30% you can calculate the specific humidity w1.
w1=0.622 Pv/(P-Pv)
where,
P = atmospheric pressure = 101.325 kPa
Pv is calculated using RH1 = Pv/Psat (@T=30 C)
Pv = RH1 * Psat (@T=30 C)
since w1 = w2
Using the same formulae from above for cooled air, just that the Psat (@T=25 C) will change.
So,
RH2 = Pv/Psat(@T=25 C)
Pv = vapor pressure remains the same in both cases.
[This problem can also be solved using a psychrometric chart.]
-------------------------------------------------------------------------------------------------------------------
If NO then,
You will have to provide more information like what is the relative humidity of the air at 15 degrees C. What are the mass flow rates of incoming streams and outgoing streams, etc