HVAC 1 Toolkit

HVAC 1 Toolkit logo.

The Toolkit for Primary HVAC System Energy Calculations is a collection of thirty-eight separate subroutines and corresponding documentation that describes algorithms for predicting the performance of HVAC components. The Toolkit documentation includes thorough descriptions of the component models and solution algorithms, detailed information on the structure of the individual FORTRAN 77 routines, as well as illustrative examples of system simulations with the Toolkit routines. The Toolkit serves two purposes: modules for large-scale simulation and stand-alone component performance prediction. The Toolkit components can also be used to calculate the energy performance of a component with a dedicated driver program to provide the necessary information flow to the Toolkit routines.

The models that form the basis for the algorithms are generally based on physical principles rather than empirical relationships and have been selected to provide information on the overall energy use and performance of HVAC systems.

Only a few components are described in this toolkit, but most of the models proposed could easily be adapted to many other situations. Priority is given here to methodological aspects of their use rather than an exhaustive cataloging of all possibilities. The following categories of primary units are described in this toolkit: boilers, chillers, cooling-towers and prime movers. Each "unit" consists of a combination of elementary components: burners, combustion chambers, heat and mass exchangers, compressors, expanders, expansion valves, engines, fans, pumps. Screen Shots


energy calculations, HVAC component algorithms, energy simulation, performance prediction



Expertise Required

Student or engineer of HVAC system design. Moderate level of computer literacy required.


Worldwide distribution and use.


Researchers, students, HVAC engineers, and developers of energy simulation programs


Interactive prompt or batch file user input. The component model must be supplied with two sets of input data: 1) The requirements (control variables and/or set points); 2) The load characteristics (conditions of use and surrounding constraints).


Output varies depending on primary unit. The simulation of the primary unit is intended to answer two questions: 1) How well are the requirements satisfied (or what is the component's "useful" output)? 2) How much does it cost (for example in terms of energy consumption)?

The program can produce output in three different ways: 1) Output written to the screen. 2) Write the entire run session to a 'log-file'. 3) Write output from runs selected during the run session.

Computer Platform

Operates under DOS and Microsoft Windows 3.1, Windows 95, Windows NT 3.5.1 or later, or Windows for Workgroups. Requires a 386 (486, Pentium, or equivalent) processor with 8 MB RAM (16 MB for Win 95 or NT), 5MB hard disk space plus 7 MB additional temporary disk space available during installation, a VGA monitor or better, a video driver capable of 640x480 resolution with 256 colors (VGA or better) and a CD-ROM drive.

Programming Language

Fortran 77


A general driver program, called HVAC1KIT, is supplied with the Toolkit. This driver program allows a user to run all of the Toolkit components and many utility programs that are provided with it in steady-state or quasi steady-state performance calculations from a desktop computer.


SI units are used throughout the toolkit.





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ASHRAE's HVAC 1 Toolkit is available for $230 ($190 for members of ASHRAE). Order on the web at www.ashrae.org/bookstore/bookstore.html. Order by phone by calling ASHRAE Customer Service at 1-800-527-4723 in the U.S. and Canada, or at (404) 636-8400 worldwide. Fax your order to (404) 321-5478. Questions about this or other ASHRAE products should be e-mailed to orders@ashrae.org.