Chapter hvac engineering Fundamentals: Part 1 Introduction

19.2
Thermodynamic Properties
of Moist Air
Moist air is a mixture of atmospheric air and water vapor. Dry air
contains no water vapor. Saturated air contains all the water it can
hold at a specified temperature and pressure. The properties of moist
Source: HVAC Systems Design Handbook
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.

---

470
Chapter Nineteen
air can be evaluated by the perfect gas laws with only a small degree
of error, which is not significant in most HVAC processes. The prop-
erties of interest in this discussion are the dry-bulb (db), wet-bulb
(wb), and dew point temperatures; humidity ratio; degree of satura-
tion; relative humidity (RH); and enthalpy and density.