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Evaporative Cooling

George E. Thomas, PE

Course Outline

The purpose of this course is to inform and educate engineers, building owners, and facilities personnel about the proper application, control, and comfort expectations of evaporative cooling in residents and commercial buildings. This course is intended to be an overview of efficient evaporative cooling systems and will allow engineers to specify and design evaporative cooling systems with confidence. This course is also intended as an overview of evaporative cooling principles and equipment for the non-technical reader. This course suggests design features that may be used to improve the economy of operation, comfort, reliability appearance, serviceability, and service life of evaporative cooling systems.

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 identify and understand:

Intended Audience

Architects, Engineers, Designers, Building Owners, Contactors, and Facility Personnel

Benefit to Attendees

The information gained from this course will allow project engineers, building owners, and facilities personnel to size, choose, and understand the proper application, control, and comfort expectations of evaporative cooling in residents and commercial buildings.

Course Introduction

Evaporation is the conversion of a liquid substance into the gaseous state. When water evaporates from the surface of something, that surface becomes much cooler because it requires heat to change the liquid into a vapor. A nice breeze on a hot day cools us because the current of air makes perspiration evaporate quickly. The heat needed for this evaporation is taken from our own bodies, and we perceive a cooling effect. This evaporation results in a reduced temperature and an increased vapor content in the air. The bigger the area of contact between the air and water the more evaporation occurs, resulting in more cooling and the addition of moisture. In order for water to evaporate, heat is required. For evaporative cooling, this heat is taken from the air, cooling it as it evaporates.

Course Content

In this lesson, you are required to download and study the following course content in PDF format:

Evaporative Cooling

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.

Course Summary

This course discusses two basic types of evaporative air coolers (EAC's), direct and indirect. Direct EAC’s are commonly used for residential and commercial cooling. Developments in the evaporative cooling industry have reliably increased the efficiency or effectiveness of the cooling media. All direct EAC’s use 100% outside air. Electricity is used by a supply fan motor and a small sump pump.

Indirect evaporative air coolers (IEAC’s) deliver evaporation across a heat exchanger, this keeps the cool moist air separated from the room air. These IEAC’s can be used in conjunction with direct EAC's and/or with refrigerated air coolers. IEAC's also use electricity for the supply fan motor, a sump pump, and a smaller secondary fan motor used for the heat exchanger’s airflow. The combination evaporative and refrigerated system has a higher first cost, but offers a good mix of energy conservation and comfort.



Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

Take a Quiz

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center 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 architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.