Super online calculators for flow and hydronics. Includes system curve wizard, variable speed pumping wizard and a whole lot of other calculators.

http://wea-inc.com/calculators.htm

http://www.youtube.com/watch?v=ECDa-U0WGZ0

Free download from here:

http://www.newfreedownloads.com/Business/Applications/Psychrometer-chart-Duct-calculator.html

A Practical Guide to Performance Measurements in Mechanical Heating, Ventilating and Air Conditioning Systems. Download here.

Mega downloads of psychrometric charts and psychrometric software!

Download dynamic psychrometric charts of Heatcraft, York, Carrier, Lennox, Marlo, and ClimateCraft.
Click here.

An extended range psychrometric chart from 20 deg f to 150 deg F in pdf format. (Right click, and "save as" to save the chart. Click here:

A useful belt sizer. Click on link:
http://www.airbalancingco.com/belt_sizer.htm

Two very interesting, and well-written spreadsheet applications in xls format. The first one is a load calculation spreadsheet, based on the Residential Loads Calculation Procedure published in ASHRAE Document GRP158 published in approximately 1980. Data Entry is indicated in Cyan (color). Please read the disclaimer. This application may prove similar to the E-20 format currently in use, and may inspire you to prepare your own calculator based on a similar format.

http://hvacindia.com/spreadsheets/resid_lds1.xls

The other spreadsheet application is a Piping Pressure Drop Calculator, also written in xls. The source is not known, so maybe the constants should be checked before using it.

http://hvacindia.com/spreadsheets/pip2_wpd_calc.xls

Spreadsheets are highly under-estimated applications and these two examples show how much more can be achieved by exploiting the capabilities of spreadsheets.

Even if you don't ever register HVACSUITE -  the free tools remain free, with no time limit, fully functional and un-crippled in any way. The free tools include : QuickStates Psychrometric Calculator, Duct calculations, Units calculator from hell, The other units calculator, A handy comprehensive database-driven contacts management tool, Programmable calculator, Construction calculator, Loan calculator, including monthly payment schedule, Stair calculator, including tread run, rise, and much more. Area, Volume, and a few other handy items. Read more details: http://hvacsuite.com/free.htm Download hvacsuite.com from: http://hvacsuite.com/HVACSuiteSetup.exe  (33mB)

Engineering Power Tools is powerful software for professional engineers. This program can greatly increase your efficiency by eliminating wasted time, looking up formulas and then performing the same calculations over and over again by hand. The software solves a wide range of commonly encountered engineering problems quickly and efficiently. Over 140 program modules and data tables are organized into one easy-to-use package. The following categories are included: Math-HVAC-Mechanical-Electrical -Materials-Structural. Context sensitive Windows Help is provided. The registered version allows saving and restoring of data files as well as printing of all forms. Engineering Power Tools can be easily networked from a single location (multiple installations are not typically required). Free download from: http://www.pwr-tools.com/

Psychrometric Functions: for microsoft Excel 5.0 or higher, a library of Visual Basic functions written especially for Excel to calculate properties of moist air. ZIP file contains library of functions and Sample XLS files showing state point calculations, mixing problems and a simple psychrometric chart. psychro.zip, 32kb.

Building Heating Load: for microsoft Excel 5.0 or higher, This is a spreadsheet to calculate approximate heating loads for a single zone. heatonly.zip, 4.7kb

Windows Duct Sizing Program: A windows application for sizing new heating and air conditioning ducts. Uses slider bars for input. Useful mainly for sizing new ducts, but can be used to calculate pressure drop through simple systems. Written with Visual Basic 3.0 and therefore requires VBRUN300.DLL in your WINDOWS\SYSTEM directory (available from microsoft). ductsize.zip, 5kb

DOS Duct Sizing Calculator: A stand alone DOS program for sizing new heating and air conditioning ducts. Imagine an RPN calculator customized for sizing ducts. Customizable, mouse aware, runs on minimum hardware. Full documentation included. I wrote this one in 1989 using QuickBASIC. duct_dos.zip, 49kb

Windows Pipe Sizing Program: A windows application for sizing new HVAC and plumbing (pressurized) pipes. Uses slider bars for input. Useful mainly for sizing new pipes, but can be used to calculate pressure drop through simple systems. Written with Visual Basic 3.0 and therefore requires VBRUN300.DLL in your WINDOWS\SYSTEM directory (available from microsoft). pipesize.zip, 9kb

http://www.hvacware.net/engrproj.html

Versaverter is a windows based, flexible unit conversion utility that uses a user modifiable web updateable, knowledge base for unit conversions. Versaverter can handle any unit conversion that follows a first order mathematic formula, and even includes a small utility to allow conversion between numeric bases. Simply select a source and destination unit from the extensive categorized list that is included with Versaverter or create your own. Then type in the number to convert - the answer is displayed as you type - it's that simple! 490kB

http://www.pawprint360.com/versaverter.zip

or

http://www.ecoustic.ca/versaverter.zip

EnergyPlus is a building energy simulation program for modeling building heating, cooling, lighting, ventilating, and other energy flows. While it is based on the most popular features and capabilities of BLAST and DOE-2, it includes many innovative simulation capabilities such as time steps of less than an hour, modular systems and plant integrated with heat balance-based zone simulation, multizone air flow, thermal comfort, and photovoltaic systems.

http://www.eere.energy.gov/buildings/energyplus/

DuctSizer - An Electronic duct calculator for sizing duct and calculating pressure drops. - 379K Updated 01/19/2004! Download and save this program to your hard drive. Double click to Unzip. The program will be located at c:Program Files/McQuay/DesignTools/DuctSizer/ductsizer.exe. We recommended sending this to your desktop as a shortcut.

PipeSizer - An Electronic pipe calculator for sizing piping and calculating pressure drops. - 374K Updated 12/29/2003! Download and save this program to your hard drive. Double click to Unzip. The program will be located at c:Program Files/McQuay/DesignTools/PipeSizer/pipesizer.exe. We recommended sending this to your desktop as a shortcut.

Psychrometric Analyzer - Provides state point and system psychrometric analysis for air handling units including cooling and heating coil loads, humidifier loads and mixed air conditions. - 286K

http://www.mcquay.com/eprise/main/mcquay/designsolutions/designtools

Free HVAC textbook in pdf format.

A stand alone DOS program for sizing new heating and air conditioning ducts.

CONTAM 2.4 is now available for download.