Who is Responsible for Proper Sizing?

In this episode, Nate Adams and Michael Housh give the HVAC 2.0 rebuttal to the idea of standard load calculations. They take a different, possibly more radical approach to proper sizing.

Michael and Nate believe in doing real-world load calculations, not just relying on models for load calculations. They are on the side of replacing equipment like-for-like unless the customer will pay for the proper load calculation; customers should have the option to get a free quote for a like-for-like or slightly smaller replacement or a full consultation, but they will often opt to choose the free quote for a similar or slightly smaller unit. The full consultation includes blower door tests and load calculations, which are keys to proper equipment sizing.

Even once we do all the typical tests for consultation (blower door, duct leakage, load calculation), there is still some room for ambiguity. The tests are not all-telling, but they exist to help the contractor and homeowner decide what the next step should be. No matter what, there will be some degree of guesswork, but there will be far less guesswork if you perform all the tests and look at utility usage.

Some problems can be “HVAC'd away,” but excessive leakage may require work on the actual shell of the home to address cracks and infiltration points. To “HVAC problems away,” proper equipment sizing will play a major role in promoting comfort.

Nate, Michael, and Bryan also discuss:

  • Like-for-like tonnage
  • Building customer relationships through consultation
  • Windows and radiant heat loads
  • Natural pressurization vs. blower door testing
  • Sizing increments and room for error
  • Air changes per hour (ACH)
  • Assessing leakage rates
  • Moisture problems and dehumidification
  • Load calculation theater
  • The consumer-oriented mindset
  • Diagnostic pyramid
  • Natural leakage
  • Communicating testing practices to your sales team

Learn more about Nathan's work, go to or

Learn more about Refrigeration Technologies HERE.

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