The Clean Air Chronicles

Chris's House

Pollard family, Monitoring,

The Pollards' House

Andrew speaking in his home

Andrew's House

reading Radon monitor,

Brian and Irene's House

Chris laughing in the basement

Chris' House

Ryan working in the basement

Ryan'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


  • 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



  • 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 Air handler images
Chris working in basement

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.

Pre Post Watt Draw Data
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 cleaner.

They added a second air cleaner to their bedroom to reduce the particle levels even further and to complement the impact of the central filtration.

Austin Healthmate filter

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.

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 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 Intervention

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

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.