Print this page HVAC Made Easy - Overview of Psychrometrics
A. Bhatia, B.E.
Course Outline
No matter what
you do in the air-conditioning industry, you will at some stage, have to use
a psychrometric chart. To perform and optimize the air-conditioning load analysis
or selection of equipment, you need to use the basics of air psychrometrics.
There are many software tools available today, which can greatly aid in the
analysis of psychrometric data, but still a fundamental understanding of psychrometrics
is essential before the software can be profitably used.
This 4-hour course provides basic overview of psychrometrics along with examples.
The course shall be useful for students, engineers, architects, designers, energy
& environment auditors, industry professionals and facility designers.
This course includes
a multiple-choice quiz at the end, which is designed to enhance the understanding
of the course materials.
Learning Objective
At the conclusion of this course, the student will:
- Be able to understand the basic terminology and definitions related to air properties;
- Be able to read psychrometric chart; and
- Be able to apply
the psychrometric charts on air-conditioning or drying applications.
Psychrometrics
is the study of the physical and thermodynamic properties of air-water vapor
mixtures. Psychrometric chart is a useful tool for visualizing moist air relations
and concepts for instance, it will answer why heated air can hold more moisture,
and conversely, how allowing moist air to cool will result in condensation.
Good understanding of Psychrometrics is essential because:
- 7 Air properties namely dry-bulb temperature, wet-bulb temperatures, relative humidity, humidity ratio, specific volume, dewpoint temperature, and enthalpy can be quickly characterized at varying conditions
- The principles of cooling and heating are based on psychrometrics.
- Psychrometrics can be used to predict changes in the environment when the amount of heat and/or water in the air changes.
- Psychrometrics
can be used to design and predict the cost of moisture removal or drying biological
materials
The versatility of the psychrometric chart lies in the fact that by knowing just two properties of moist air, the other properties can be determined.
Course Content
The the course content is in a PDF file HVAC Made Easy - Overview of Psychrometrics . You need to open or download this document to study this course.
Course SummaryA psychrometric
chart graphically describes the relationship of seven air properties under variety
of conditions and illustrates how these properties change as the heat and moisture
content of the air changes.
The psychrometric chart graphically represents the interrelation of air temperature
and moisture content. This aspect of psychrometrics is very important when it
comes to analyzing indoor conditions as temperatures and humidity levels within
our environments are very dynamic.
In air-conditioning applications the knowledge of psychrometrics is essential
to design the system for optimal thermal comfort. Thermal comfort is that condition
of mind that expresses satisfaction with the thermal environment. The air conditioning
engineer uses the psychometric chart to analyze how the state of moist air alters
as an air conditioning process takes place.
The engineers in industry fields it useful to design the process systems, ventilation
of livestock building, moisture control applications and variety of drying applications
such as drying of grains, leaves, ceramic, art objects etc. etc.
A solid understanding of psychrometrics can prevent costly mistakes in the design
and operation of commercial, residential, industrial cooling, dehumidification,
drying and humidification systems.
A lot of energy is used in air-conditioning, and with an understanding of psychrometrics
you can estimate energy flows, evaluate performance and plan energy conservation.
Related Reading
Understanding Psychrometrics,
ISBN 1-931862-14-1, published by the American Society of Heating, Refrigeration
and Air Conditioning Engineers (ASHRAE), provides a practical desk reference
book for air conditioning designers, process engineers and meteorologists and
a learning module for students and those new in the field.
Once
you finish studying the
above course content,
you need to
take a quiz
to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDHonline.com or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
