EP255 Beyond Manual J: The Heat Balance Future of Residential Load Calculations With Tony Amadio (December 2025)

Notable quote from the episode: Make it as simple as possible, but not simpler.

In this episode, Eric Kaiser sits down with mechanical engineer Tony Amadio, the founder of True Loads, to talk about what actually makes residential load calculations succeed or fail in the real world. Tony shares how his work is split between builders, architects, project managers, and HVAC contractors, and why the biggest early battle was simply getting people to trust results that pointed to smaller equipment. He explains how he quickly learned from feedback loops in production housing, including what happens when people "over-vent" tiny spaces like closets and bathrooms, accidentally stealing airflow from bedrooms where it matters.

Tony walks through his approach to receiving plans, emphasizing the importance of nailing down the building envelope inputs (windows, insulation, attic conditions) and getting key assumptions in writing. On renovations, he emphasizes that uncertainty is normal, so you lean on photos, field verification, and practical guidance to keep the model honest. They dig into infiltration and leakage, where Tony argues the models are still imperfect even with blower door data, and the real win is setting expectations: the HVAC design works under specific building conditions, and if the building does not match those conditions, performance issues are not automatically "bad calcs."

The conversation closes with a discussion of equipment selection, humidity, and where the industry is headed. Tony makes a clear point: most standard residential systems do not directly control humidity, and the code focuses on temperature performance, not a promised indoor RH target. They also touch on ACCA Manual S updates, oversizing rules for staged equipment, and Tony's upcoming True Loads software, which uses the ASHRAE Heat Balance method to represent modern construction and time-lag effects better, while aiming to require fewer inputs than traditional Manual J workflows.

TrueLoads website: https://1dtrueloads.com/

Tony on LinkedIn: https://www.linkedin.com/in/anthony-amadio-pe-7360952a/

This episode was recorded in December 2025.