Psychrometrics of Air
The computer program PSYCHRO is an ACADS-BSG program which was developed by G.J.Van Aken in Canberra ACT. It computes the thermodynamic properties of moist air, at any atmospheric pressure, from its dry bulb temperature and one of four other parameters. The program applies to air conditioning and refrigeration, or any process involving heat and mass transfer in moist air. The program has been tested against ASHRAE data over the temperature range of -40 C to 200 C at standard atmospheric pressure (101.325 kPa) and at 84.556 kPa. However, the sub-programs used in this program are valid for the temperature range of -125 C to the critical temperature of water at 374.15 C, and a pressure range from 1 to 5000 kPa.
INPUT DATA REQUIRED
All input data is interactively entered through the keyboard as prompted on the screen.
First the atmospheric pressure must be established. This may be entered directly in kPa or, alternatively, by elevation in metres above sea level in the range from -1000m to 12000m (113.930 kPa to 19.286 kPa). The default is for 101.325 kPa which is the standard atmospheric pressure at sea level. A listing of elevations for some typical locations can be displayed upon request. Pressures occurring outside the valid elevation range must be entered directly in kPa, in which case the valid range is from 1kPa to 5000kPa.
The next request is for the entry of the dry bulb temperature. The valid range for this parameter is from -125 C to the critical temperature of water at 374.15 C. After this entry one of four options must be selected and entered as the second parameter to complete the input requirements for the program. These options are:
Wet Bulb Temperature Relative Humidity
Dew Point Temperature Humidity Ratio
All the parameters that can be obtained from a psychrometric chart are displayed and in addition to this the density and specific heat of the moist air mixture, and the water vapour pressures are also displayed.
PSYCHRO is one of the ACADS BSG Shareware programs. Shareware relies upon the honesty of the software users to pay for the software they use. It avoids the cost of marketing and promotion by inviting users to give copies to their friends. A nominal registration fee is charged for the program, this fee contributing to the original development and future enhancements. By registering, users are kept informed of future updates and improvements to the program.
The program is available for use on a micro computer running MSDOS. Copies of the program are supplied on 3.5" IBM formatted diskettes.
For further information including pricing, contact the ACADS-BSG Office in Glen Iris or at firstname.lastname@example.org
Home page- http://www.ozemail.com.au/~acadsbsg/