Green Building Community

Air Filtration at the #1920sMakeoverATL Showhouse - It Can Only Get Better from Here (Video)

Rate It Green Team 0 Ratings 105 Discussions 6 Group posts

Posted by: Rate It Green Team

We might say Green Builder Matt Hoots is having too much fun filming informative videos to let us in on the behind the scenes action at the start of the #1920sATLMakeover deep energy retrofit project, but breathing unhealthy air is of course not good for him or anyone else.    

As Matt correctly, points out, "Indoor air quality was not top of mind when they’ve been renovating this house over the years.”  

Indeed, Matt found a 2” gap on the top of the air filter, so as he points out, the filter is doing absolutely nothing.  And, he also found evidence of a family of rats making themselves at home in the basement of someone’s home.  As Matt shares, if a filter is not installed properly, there’s going to be blow by (air going around the filter instead of THROUGH it) which means it’s basically doing nothing.  Critters might be an extreme example, but there are certainly going to be challenges with particulates.  

We talk about what filters might not be blocking, but the evidence at this 1920’s home is pretty visible.  On the one hand, there’s the rodent challenge.  On the other, PM2.5 dust particles are 20 times smaller than a human hair and have been judged by the US EPA to be damaging to human health.  Additional lurking dangers in this home the team will be testing for include mold, lead, asbestos, and radon. Matt points out this is a potentially toxic mixture, one that he describes graphically getting worse when it rains.   

It’s terrific to have a partner like Aprilaire for this project, to provide a whole-house HVAC system that will deliver quality filtration, ventilation, and humidity control, so that the building team as well as future occupants can literally breathe easier. According to Joseph Hillenmeyer at Aprilaire, "A new standard in health and indoor air quality is emerging in the home building industry - one that recognizes the importance of utilizing the best solutions available when addressing home buyer concerns about the impact of their living space on their family’s health… Progressive builders that are addressing IAQ concerns understand that building healthy homes is a holistic initiative requiring attention to the building envelope, Low VOC materials, and the components of the HVAC system.”   

Joseph makes the point that a key, impactful change most builders can and should make is to standardize filtration at MERV 13. MERV stands for the Minimum Efficiency Rating Value of filters, basically how fine the filter is and what types of irritants and air pollutants it can keep out of a home’s ventilation systems and air.  The higher the MERV rating, the more particles a properly installed filter will trap. At a lower, basic level like MERV 6, a filter can trap dust and lint particles as well as pollen, where a MERV 13 keeps out a host of pollutants, including viruses and bacteria, as well as other particles such as dust mites, mold, pet dander, smoke, and smog components.  MERV 13 provides at least 85% airborne capture particles that are PM 2.5 or smaller - 30 times smaller than a human hair, and they are recognized by the EPA as most damaging to long-term human health.  


Whole house builder-provided filtration is the most effective way to combat PM2.5, as the filters are installed as a part of the HVAC system, as opposed to room air purifiers. A whole house system provides a new level of home air quality, and also provides a family with more breathable air from the first day they move into their home.  


We spend up to 90% of our time indoors, according to the EPA, and more in the recent year due to the COVID-19 pandemic.  We look forward to learning more about the HVAC plans for the #1920sMakeoverATL home so we can better learn about the evolving technologies which will help us better protect the health of all building occupants. Better ventilation is the right thing to do for those working on the project as well as the homeowners who will be so excited to move in to the completed home.   



Please be kind and respectful!

Please make sure to be respectful of the organizations and companies, and other Rate It Green members that make up our community. We welcome praise and advice and even criticism but all posted content and ratings should be constructive in nature. For guidance on what constitutes suitable content on the Rate It Green site, please refer to the User Agreement and Site Rules.

The opinions, comments, ratings and all content posted by member on the Rate It Green website are the comments and opinions of the individual members who posts them only and do not necessarily reflect the views or policies or policies of Rate It Green. Rate It Green Team Members will monitor posted content for unsuitable content, but we also ask for the participation of community members in helping to keep the site a comfortable and open public forum of ideas. Please email all questions and concerns to