Psychrometric chart software used by 20,000+ users world-wide.

Hands Down Software (HDS) is now part of Carmel Software. We will continue HDS's mission to offer the best psychrometric chart software on the market. We are proud to now serve the 20,000+ customers that HDS has acquired over 25 years in business.

Mobile and web apps for HVAC and engineering businesses.

Carmel Software licenses HVAC and engineering applications for Apple iOS and Android-based mobile devices that simplify field-based calculations - no matter where you are. We also offer customized versions of our apps for many organizations to provide even further targeted solutions to installing, selecting, and managing HVAC equipment.


The #1 Psychrometric Chart Software Tool in the World
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HVAC Noise Prediction and Acoustical Analysis
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Commercial and Residential HVAC Load Calculations
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Cleanroom and Fab Energy Simulation Analysis Program
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About Hands Down Software

Bob Hanna founded Hands Down Software in 1987 and developed the current Windows version of HDPsyChart in the mid-1990s. Since then, over 20,000+ engineers, manufacturers, data center managers, and building owners have relied on this software for their psychrometric calculations.
In the Spring of 2024, Carmel Software acquired Hands Down along with the psychrometric chart, HVAC acoustical analysis, HVAC load calculations, clean room design and other software tools. Click here for a list of all the Hands Down Software tools.