The Clean Air Chronicles - Chris's House

Watch Chris's story

The air handler intervention at Chris Guignon’s house was one of the first that ROCIS performed. It was a good opportunity to learn, and it made a significant impact on the particle and comfort levels in the Guignon household. Check out the technical details below.

Note: All costs were calculated in 2017; costs will fluctuate with changing energy prices.

Intervention Summary

Problem as Found

  • Oversized ¾ HP blower
  • Heating mode was shutting down on high limit
  • Watt-draw of 1,470 W (continuous & AC mode)
  • Significant restrictions from 1” filter & duct systems
  • Total external static pressure (TESP): 239 Pa
  • Air movement through the duct system was too low
  • 2nd floor was uncomfortable in the winter and summer
  • Cost of operating blower continuously: $1,000 kWh/month → $120/month

Solution & Results

  • Installed new blower (Digi Motor Constant Torque ECM) to lower energy use, provide more control over the settings, and optimize airflow.
  • Modified return air system to increase airflow, specifically by adding a larger return drop and sealing the return duct in the basement.
  • Added a horizontal filter slot in the filter drop to accommodate a larger and deeper MERV 13 filter.
  • Much better filtration from continuous fan operation
  • Post-intervention watt-draw: 120 W (in continuous mode). In AC mode, the improvements were also significant: a reduction of 840 W
  • Post-intervention TESP: 79 Pa
  • Improved comfort on the 2nd floor from continuous flow
  • Cost of operating new motor in continuous (24/7) mode: $12.50/month



Chris's Air Handler Pre and Post Retrofit with enlarged return drop and new ECM motor, Merv 13 filter air handler, ECM replacement, ROCIS intervention

Without this intervention, it would have been very expensive for Chris to run his air handler continuously. But with a new motor, the watt-draw dropped to a fraction of where it started.

Air Handler Interventions chart

Chris & his daughter

Prior to participating in the Low Cost Monitoring Project, Chris and his wife used an air cleaner in their daughter’s bedroom. Austin air cleanerThey added a second air cleaner to their bedroom to reduce the particle levels even further and to complement the impact of the central filtration.

Portable Air Cleaners

As the Guignon family found out, a high-quality portable air cleaner can dramatically reduce particle counts in the rooms where they are used. Check out our page on PACs to learn more.

Learn More About Portable Air Cleaners

Air Handler Checklist

Is your house ready for an air handler intervention? Need some guidance to help figure it out? Ask your HVAC contractor to use the checklist on this page to assess your system.

Air Handler Checklist

Air Handler Inquiry

We lay out the whole process for assessing your air handler system for a retrofit on this page. It's a great place to get started.

Air Handler Inquiry

Air Handler Intervention

This green HVACR article provides a summary of the ROCIS air handler intervention practices for improving efficiency & IAQ. 

Read the Green HVAC Article

The Breathe Collaborative

The Breathe Collaborative is an organization dedicated to improving the air quality in Southwestern Pennsylvania. They offer a range of tools for monitoring and reporting on local air quality.

Learn More About The Breathe Collaborative