**@Air** is a member of Techware’s family of software packages
bringing accurate thermodynamic properties of fluids to many popular
Windows programs.** @Air**
provides thermodynamic properties (sometimes called psychrometric
properties) and transport properties of moist air.

The air property functions can be used directly from within applications including Microsoft Excel, 1-2-3 and MathCad. Add-ins attach the functions so that you can use them as if they were built in to the applications.

This version supports 32-bit and 64-bit applications. New 64-bit
components include the air function library (DLL), the Excel Add-in and
**DeskTop Air**. The package also includes 32-bit versions of these
components plus the add-ins for 1-2-3 and MathCad.

Programmers can call the functions in the dynamic link library directly from many Windows programming languages such as Microsoft Visual BASIC, Microsoft Visual C++ for Windows and Microsoft Access.

**@Air**
is going to change the way you solve many problems involving moist air!
Your calculations will be greatly simplified and their accuracy
will be improved by using the** @Air** functions. The functions in **@Air** will help you calculate the
performance of HVAC equipment, evaporative coolers, air compressors and
air turbines. You can conveniently design equipment right on your favorite
spreadsheet and your results will be more accurate because you won’t
have to interpolate data from tables, read from psychrometric charts or
construct graphical solutions. You won’t have to make perfect gas assumptions either.

- Added 64-bit version of Air property DLL.
- Added 64-bit version of
*DeskTop Air*. - Converted all help files to compiled HTML format.
- Removed @Air Help link from all versions of Excel and 1-2-3 menus.

- Removed Help file link from Help Menu for Excel 2007 and later.
- Corrected a bug in the Expansion Tool on DeskTop Air

**@Air**** 3.2** is available as a
free
upgrade to licensed users of **@Air 3.0** or **@Air 3.1.**

**@Air 3.1** is a minor upgrade for **@Air 3.0**. It
includes a new unit set, METF similar to MET but using kg/cm^{2} for pressure instead of
bar. In addition, it includes some minor bug fixes and
improvements to the accuracy of the transport property functions for
viscosity and thermal conductivity.

**@Air**** 3.1** is available as a
free
upgrade to licensed users of **@Air 3.0**.

- Extends the temperature range upwards from 200 °C, (392 °F) to 2000 °K, (3140 °F).
- Adds transport property functions:
- AirPTWC, which calculates specific heat given pressure, temperature and humidity ratio.
- AirPTWM, which calculates dynamic viscosity given pressure, temperature and humidity ratio.
- AirPTWK, which calculates thermal conductivity given pressure, temperature and humidity ratio.

- Includes
**DeskTop Air,**an advanced air property calculator with many improved features over the previous air property calculator. - Adds four new unit sets, EngG using psig for pressure instead of psia, SIF, which uses the formal SI units, MPa for pressure instead of bar and °K for temperature, instead of °C, SIK using kPa instead of bar for pressure and MET using the calorie instead of the joule for energy.
- Allows specific properties to be expressed on either a dry or wet basis.
- Allows the humidity ratio parameter to be input alternately, as mole fraction or mass fraction.
- Added new thermodynamic functions:
- AirPTHs, which calculates saturated enthalpy given pressure and temperature.
- AirPHTs, which calculates saturation temperature for a given pressure and enthalpy.
- AirWX, which calculates either the mole or mass fraction given the humidity ratio.
- AirXW, which calculates the humidity ratio given either the mole or mass fraction.

- Improved installation program that allows distribution over the web.
- Includes new thermodynamic functions
- AirPTHs, which calculates saturated enthalpy given pressure and temperature.
- AirPHTs, which calculates saturation temperature for a given pressure and enthalpy.
- AirWX, which calculates either the mole or mass fraction given the humidity ratio.
- AirXW, which calculates the humidity ratio given either the mole or mass fraction.

- Functions can be used as if they were built in to most popular spreadsheet programs.
- Accurate properties consistent with ASHRAE tables.
- Equations based on virial equation of state using second and third order mixing coefficients. No perfect gas assumptions.
- Accuracy fully documented.
- Supports many combinations of input data.
- Calculates specific volume, enthalpy, entropy, specific heat, viscosity or thermal conductivity.
- Use English, English Gage, SI Common, SI Formal, SI kPa and Metric unit sets.
- Functions can be called from many Windows programming languages.
- Allows pressures up to 50 bar (725 psia) and temperatures from 180 °K (-135.7 °F) to 2000 °K (3140.3 °F).
- Uses or calculates humidity ratio, relative humidity, degree of saturation, wet bulb or dew point temperatures.
- Express moisture as humidity ratio, mole fraction or mass fraction.
- Express results on wet or dry basis.
- Check pricing for attractive quantity discounts.

The **@Air** package includes various add-ins which link
the functions to many popular 32-bit and 64-bit Windows applications.
32-bit add-ins
are included for Microsoft Excel Versions for Office 95, Office 97, Office
2000, Office XP, Office 2003, Office 2007 and Office 2010 (32-bit version); Lotus 1-2-3 97 and 1-2-3 Millennium and MathSoft Mathcad
Plus Versions 6, 7 and 8. A 64-bit add-in is included for Office
2010 (64-bit version.)

No programming is required to use the **@Air**
functions with any of these applications. Just follow a few simple steps
to load the add-in, and from then on, the functions will be available
every time you start the application. You use the functions just like any
of the built-in functions. The functions can be used in any spreadsheet
formula and any argument to the functions can be a number, a formula or a
cell reference.

All of the steam property functions are contained in a Windows Dynamic
Link Library (DLL). The **@Air** package includes 32-bit
and 64-bit versions of the DLL, which supports applications designed for Windows 95,
98, NT, 2000, XP, Vista and Windows 7. Function prototypes and LIB files are
included in the package to support Microsoft C/C++ compilers. Declaration
files are included to facilitate programming with Microsoft Visual Basic
or Microsoft Access.

Go Back to Key Features

The following table lists all of the **@Air**
functions currently available.

Function(Input Arguments) |
Output Value |

AirPTWV(P,T,W,unit) | Specific Volume |

AirPVWT(P,V,W,unit) | Dry Bulb Temperature |

AirTVWP(T,V,W,unit) | Pressure |

AirPTW(P,T,unit) | Saturated Humidity Ratio |

AirPWD(P,W,unit) | Dew Point Temperature |

AirPTRW(P,T,RH,unit) | Moisture |

AirPTWR(P,T,W,unit) | Relative Humidity |

AirPTWB(P,T,W,unit) | Wet Bulb Temperature |

AirPTBW(P,T,B,unit) | Moisture |

AirPBWT(P,B,W,unit) | Dry Bulb Temperature |

AirPBRT(P,B,R,unit) | Dry Bulb Temperature |

AirPTWU(P,T,W,unit) | Degree of Saturation |

AirPTUW(P,T,U,unit) | Moisture |

AirPTWH(P,T,W,unit) | Specific Enthalpy |

AirPTHs(P,T,unit) | Saturated Enthalpy |

AirPWHT(P,W,H,unit) | Dry Bulb Temperature |

AirPHWT(P,H,W,unit) | Dry Bulb Temperature |

AirPHTs(P,H,unit) | Saturated Dry Bulb Temperature |

AirPTWS(P,T,W,unit) | Specific Entropy |

AirPWST(P,W,S,unit) | Dry Bulb Temperature |

AirPSWT(P,S,W,units) | Dry Bulb Temperature |

AirPTWC(P,T,W,units) | Specific Heat |

AirPTWM(P,T,W,units) | Dynamic Viscosity |

AirPTWK(P,T,W,units) | Thermal Conductivity |

AirVapPT(Pvap,unit) | Saturation Temperature of Water |

AirVapTP(T,unit) | Saturation Pressure of Water |

AirCondPTH(P,T,unit) | Enthalpy of Compressed Liquid Water |

AirCondPTS(P,T,unit) | Entropy of Compressed Liquid Water |

AirWX(W) | Mole or mass fraction |

AirXW(X) | Humidity Ratio |

AirVer() | Version and serial number |

- Note:
- P = Pressure
- Pvap = water vapor pressure
- T = Dry Bulb Temperature
- V = Specific Volume
- W = Moisture defaults to humidity ratio but can be mole or mass
fraction by adding
**C**or**M**to unit set. - RH = Relative Humidity
- B = Wet Bulb Temperature
- H = Enthalpy
- S = Entropy
- C = Specific Heat
- M = Dynamic Viscosity
- K = Thermal Conductivity
- U = Degree of Saturation
- X = Mole or mass fraction
- unit = Unit Set

The UnitSet argument is used to select the unit set, formulations and other calculation options.

When calling the functions from 1-2-3, the function name is preceded by the "@" character, eg. @AirPTWH(P,T,W,unit) for 1-2-3

If you wish to try **@Air**, you may
download
a fully functioning copy for a 30 day evaluation period. You may
also use this download as a replacement for a lost or damaged copy of **@Air
4.0**. If you decide to purchase **@Air** you may use the
download and we will provide you with a serial number for permanent
use. Go to our Order page when you are ready to purchase **@Air**.