Using the Roomulator w/ Chris Hughes

In this episode of the HVAC School Podcast, host Bryan Orr speaks with Chris Hughes of The Energy Conservatory (TEC) about using the Roomulator card and DG-8 manometer for room pressurization testing.

Chris provides background on how he came up with the idea for the Roomulator. He wanted an easy way for technicians to properly size passive returns to relieve pressure imbalances between bedrooms and the main body of a home. The Roomulator card enables technicians to quickly measure door undercuts and size transfer ducts, grilles, etc., to reduce room pressures to 3 Pascals or less per ENERGY STAR guidelines. When paired with the DG-8 micromanometer, the system provides precision room pressurization measurement.

They discuss reasons why excessive room pressures can cause comfort, efficiency, and indoor air quality issues. Removing positive pressure helps reduce airflow through leaks in exterior walls, lighting fixtures, etc. Chris also talks about how the Roomulator is an affordable “gateway tool” for technicians to get started with building science and air pressure dynamics. DG-8 allows technicians to perform several other tests beyond room pressurization as they advance their skills.

Key topics covered:

  • TrueFlow grid and DG-8 manometer
  • Origins and purpose of the Roomulator card
  • The step-by-step process for using Roomulator and DG-8
  • Impacts of room pressurization on comfort, efficiency, IAQ
  • Role as an introductory tool for building science testing
  • The collaboration of NCI and TEC

You can learn more about the Roomulator and purchase a few at

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