# An Encapsulated Crawlspace: Basic Engineering Calculations and Measurements

Course Number: BD-4025
Credit: 4 PDH
Subject Matter Expert: Wayne D. Erickson ScD, P.E.
Price: \$119.80 Purchase using Reward Tokens. Details
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Overview

#### In An Encapsulated Crawlspace: Basic Engineering Calculations and Measurements, you'll learn ...

• Working equations from first principals for application to a crawlspace environment
• Measurements with calculations to examine performance of an encapsulated crawlspace
• Time-history measurements of temperature and relative humidity at several crawlspace locations
• Dew point and other parameter calculations from measured temperature and relative humidity

#### Overview

Preview a portion of this course before purchasing it.

Credit: 4 PDH

Length: 28 pages

Students of this course will learn how to calculate and measure the parameters that affect moisture in an enclosed space, such as a crawlspace. The application is not limited to a crawlspace, although measurements taken by the author and calculations presented in the course are based on a particular residential encapsulated crawlspace.

The course begins with a very brief discussion of encapsulation of a crawlspace. Equations based on first principals are introduced along with the definition of terms. Numerous examples are given with graphical representations to support the development and application of the equations. The basic concepts on which this course is based should be familiar to all engineers or easy to grasp, particularly for mechanical and chemical engineers.

The starting point for developing a set of working equations includes an expression for the vapor pressure of water as a function of temperature, the definition of relative humidity, the ideal gas equation for air containing water vapor, the definition of partial pressure and a definition of dew point. The procedure for combining these expressions into a set of working equations is then presented. The working equations are used to calculate dew-point temperature, mass fraction of water vapor in air, specific volume of moist air, enthalpy of air/water vapor mixtures including water condensation, and other properties. Two sets of temperature and relative humidity measurements made over time and at several locations in an enclosed crawlspace are presented. These measurements are presented graphically and include the corresponding calculated dew-point temperatures. An EXCEL program listing is included that uses the working equations and provides a convenient way to combine the measured and calculated results.

A drawing of a functional encapsulated crawlspace is presented with the locations of the temperature and humidity sensors, and the location of the dehumidifier and its associated duct work. A photograph of the encapsulated crawlspace is also included. Measurements of temperature and relative humidity at several locations in the crawlspace are presented and used to determine dew point and other parameters of interest. Measurements of the wood moisture content at a number of locations around the sill plate and along one of the girders are given. These measurements are compared to an empirical correlation that relates wood equilibrium moisture content to relative humidity and temperature. The amount of electricity used by the crawlspace dehumidifier over time is also measured and briefly discussed.

#### Specific Knowledge or Skill Obtained

This course teaches the following specific knowledge and skills:

• Working equations from first principals for application to a crawlspace environment
• Measurements with calculations to examine performance of an encapsulated crawlspace
• Time-history measurements of temperature and relative humidity at several crawlspace locations
• Dew point and other parameter calculations from measured temperature and relative humidity
• Measured wood moisture content
• Wood moisture content measurements compared to equilibrium moisture content
• Dehumidifier electrical power consumption over time in an encapsulated crawlspace
• Calculation procedure for heat rejection rate from a dedicated crawlspace dehumidifier

#### Certificate of Completion

You will be able to immediately print a certificate of completion after passing a multiple-choice quiz consisting of 20 questions. PDH credits are not awarded until the course is completed and quiz is passed.

Board Acceptance
 This course is applicable to professional engineers in: Alabama (P.E.) Alaska (P.E.) Arkansas (P.E.) Delaware (P.E.) Florida (P.E. Area of Practice) Georgia (P.E.) Idaho (P.E.) Illinois (P.E.) Illinois (S.E.) Indiana (P.E.) Iowa (P.E.) Kansas (P.E.) Kentucky (P.E.) Louisiana (P.E.) Maine (P.E.) Maryland (P.E.) Michigan (P.E.) Minnesota (P.E.) Mississippi (P.E.) Missouri (P.E.) Montana (P.E.) Nebraska (P.E.) Nevada (P.E.) New Hampshire (P.E.) New Jersey (P.E.) New Mexico (P.E.) New York (P.E.) North Carolina (P.E.) North Dakota (P.E.) Ohio (P.E. Self-Paced) Oklahoma (P.E.) Oregon (P.E.) Pennsylvania (P.E.) South Carolina (P.E.) South Dakota (P.E.) Tennessee (P.E.) Texas (P.E.) Utah (P.E.) Vermont (P.E.) Virginia (P.E.) West Virginia (P.E.) Wisconsin (P.E.) Wyoming (P.E.)
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More Details

Preview a portion of this course before purchasing it.

Credit: 4 PDH

Length: 28 pages