EP239 Psychrometrics, Mobile Apps, and the Future of HVAC with Carmel Software (September 2025)

Stephen Roth—founder of Carmel Software and current owner of Hands Down Software—joins Bill and Eric to trace a multigenerational journey from a 1920s Ohio roofing firm to modern HVAC software that powers everyday field work. Stephen shares how family roots in commercial roofing and energy management shaped his path as a mechanical engineer and coder, eventually leading to Autodesk acquiring his early load-calc assets and, later, to relaunching Carmel with one of the industry’s first mobile HVAC app suites.

Today CarmelSoft offers field-friendly tools from PT charts and duct/pipe sizers to an ACCA-approved Manual J (HVAC ResLoad J) iPad app. Stephen also discusses custom projects for Carrier, Mitsubishi, SMACNA, and ASHRAE (including Building EQ), plus the acquisition and revitalization of the ubiquitous Hands Down psychrometric chart software. Looking ahead, he sees AI accelerating data entry, plotting psychrometric processes by prompt, and facilitating web-based collaboration—always in service of the core mission: helping technicians and engineers accurately size systems and design energy-efficient buildings.

Notable quotes:

“Our mission is to help technicians and engineers easily and accurately design energy-efficient buildings.” — Stephen Roth

“The city of Phoenix wouldn’t exist without our industry.” — Stephen Roth

Stephen’s LinkedIn: https://www.linkedin.com/in/stephenbroth/

Camelsoft website: https://carmelsoft.com/

HandsDown website: https://www.handsdownsoftware.com/

Upcoming webinars: https://carmelsoft.com/Carmel-Software-Mobile-Training-Webinars

Past recorded webinars: https://carmelsoft.com/Carmel-Software-Video-List

Contact form: https://carmelsoft.com/Carmel_Software_ContactUs.aspx

This episode was recorded in September 2025.