5. Psychrometric related software

DOS based software
1.
PSYCHART: by Drs. D.S. Fon and Wei Fang¡ANational Taiwan University, 1986
2.
PSCHART: author unknown. Download psy1.zip (psychart and pschart)
3.
PLUS: by Dr. L.D. Albright¡ACornell University, 1990

WINDOWS based software
4.
m files: require MATLAB to run. (by: W. Fang, 2002)
5.
JPsye.zip: Zipped file of JPsye.exe ver.0.93 (by: Jian Z.H. and W. Fang, 2001)
Descriptions of above 2 software (in Chinese): More details
6.
PsyChart_C.zip: Zipped file of PsyChart_C.exe, the Chinese version of JPsye.exe ver.0.93 (by: Jian Z.H. and W. Fang, 2001)
7.
JPsye0926.zip: Zipped file of JPsye0926.exe ver 1.0Beta (by: Jian, Z.H. and W. Fang, 2001)
8.
Psyc0226.zip: Zipped file of psyc0226.exe (newest version of the Psychart Software, by: Jian, Z.H. and W. Fang, 2002)
9.
PSY.xls: (by: W. Fang, 2001)

If your PC have installed msowc (microsoft office web component), you are able to run the following programs through the Internet. The contents are the same with psy.xls.
run¡@psy1&2¡@psy3¡@psy4&5¡@psy6&7¡@psy8&9¡@psy10¡@

Source of the equations used in above software:

ASAE psychrometric data and Chap 6 of ASHRAE fundamentals Handbook, 1993.

The following files are for Window version Psychart Software

Tutorial

The following User manual is for DOS version Psychart Software

5.1¡BObjective

Psychrometric properties of the air within a greenhouse indicate energy requirement and crop response. These properties usually need to be calculated repetitively. The PSYCHART software replaces the traditional chart method. A total of 10 psychrometric properties are included in this software. Once two of the indenpendent properties are specificed, all other properties will be shown, either in English or Metric unit. This software is a modified version of the software written by the author and Dr. D.S. Fon of the Department of Agricultural Machinery Engineering, National Taiwan University.

5.2¡BProgram Execution

5.2.1. Start

Enter PSYCHART under the DOS prompt.

5.2.2. Enter data

Select 'Unit' option to toggle between English and SI units. Select 'Run' option to enter data input mode. Within the data input mode, user can enter 'q' followed by <Enter> to exit from this mode at any time. There are 45 possible combinations if any two different properties are presented as a pair. Not any pair of properties are independent. The software provides a Table to describe all the independent pairs (see 'Table' option in main menu). The software can handle most of these different initial conditions (34 pairs).

5.2.3. Output

Select 'Print' from the main menu, the software will print out values in both English and Metric unit. Select 'Save' to store calculated data into 'Psychart.rpt' file and select 'List' to view the contents of the generated file. When in 'SI' unit mode, user can select 'Chart' to view the graphical format of the psychrometric chart.

5.2.4. Valid data range

In terms of user friendliness, the software provides a data range verification before the actual calculation. The software will perform the verification in two steps: 1st: determined whether the user defined two properties are dependent or not. If not, a short message explaining what type of error occurred will appear at the bottom of the monitor. 2nd: determined the range of the available values based on the assigned dry-bulb temperature. The software will use the assigned dry-bulb temperature as the first property and assume the relative humidity is 0 % and 100% to calculate the minimum and maximum values of the user assigned second property. If the value entered by the user does not fit within the valid range, a proper message and valid range values will appear at the bottom of the monitor. For example, if the dry-bulb temperature is 80 ¢K, then the valid range of other properties (values of PS and LH are not affected by RH) are listed as follows:
wet-bulb temperature (WB)
50.102
to
80
¢K
dew point temperature (DP)
0
to
80
¢K
humidity ratio (HR)
0
to
0.02222
lb vapor/lb dry air
specific volume (SV)
13.606
to
14.092
ft3/lb dry air
enthalpy (EN)
19.24
to
43.605
Btu/lb dry air
saturated vapor pressure (PS)
0.507
Psi
latent heat (LH)
1048.545
Btu/lb dry air
vapor pressure (PV)
0
to
0.507
Psi

5.2.5. Unit conversion

from English
multiple by
to Metric
ft3/lb dry air
0.06242796
m3/kg dry air
Btu/lb dry air
2.3244
kJ/kg dry air
psi
6894.76
Pascal

¡° Enthalpy of English unit and Metric unit have different basis, thus, can not be converted directly.