Hello Home Energy Pros,
I'm looking for resources, articles, studies about how radon mitigation systems impact energy efficiency (electricity consumption from active systems, potential increases in air changes, changes to a HERS score, etc.).
If you know of a study or article based on good evidence and/or sound modeling, please paste a link in a reply.
Utah Clean Energy
I can comment based upon experience with construction and as a building official concerning semi-tight and passive house design.
First as a building official the Town had adopted a requirement for a minimum passive radon removal system before I was hired based upon minimal charges to install and heavy readings up to 225 pic in random testing. The basic system was basically a perforated pipe with a cloth sleeve installed as a loop around the interior house foundation in pea gravel, a moisture/radon material with heat welded seams and positive foundation connection and a three inch pipe inside one for the interior walls that could have an exhaust fan installed if necessary. This worked for every house to reduce the radon to acceptable standards to meet the EPA regulations.
On to my actual building experience. I had watched radon barriers of 6 mil sheet plastic with or without tape seams that were installed over the rock materials fail before construction was completed or allow moisture entry in the open lap seams. I found a 20 mil reinforced PVC membrane in used billboard sign faces that could be heat or chemically welded to provide both the moisture and radon barrier properties that I desired. There are other commercial systems available for this application. In my own new house that incorporated many air tight application barriers, I used the passive system in a none radon area and have had a zero reading while neighbors have a 20 to 40 reading. One additional thing that I used was a black ABS pipe through the roof that heats up and starts a convective current to pull any radon naturally.
The system works at a lesser cost than a retro fit application and builders who provide this initially have no problems during the house sale. Thus right or wrong a smart builder would create a solution at the least possible cost to make sure the home sells.
Thank you for raising this issue on the blog.
The defining study on weatherization and radon, as best I can tell, was performed by the Oak Ridge National Laboratory: httpweatherization.ornl.govRetrospectivepdfsORNL_TM-2014_338.pdf
Some of the participants in this study reported on their findings in the Spring Issue 2017 of Home Energy magazine: http://homeenergy.org/show/article/nav/hvac/id/2162
The conclusion, with plenty of caveats about uncertainty and the lack of in-depth long-term research regarding radon and weatherization, was that "On average, radon levels increased among treated homes following weatherization". Despite many caveats, the authors reported that statistically "there is less than 1 chance in 1,000 of observing a difference as large as we did between the two groups if weatherization has no effect on radon levels." The increase was not dramatically significant in absolute terms: an average of 0.4 picocuries per liter of air. However, in high-radon counties the control-adjusted increase was 40% (at 1.1pCi/l). They also observed beneficial effects on radon and other IAQ issues in a small study group where ASHRAE 62.2 compliant ventilation fans were introduced.
It is interesting to me that the microbiological effects of radon are disputed by some. A leading researcher at Columbia University (Professor Guy Garty) recently presented at a meeting of radon stakeholders in Johnson City, NY. His presentation was unequivocal about the health dangers related to radon - a subject he is personally interested in as his family's home is a high-radon area. The research is pretty definitive and lengthy on the health impacts of exposure to radon.
By the way, the Oak Ridge report acknowledges that there are many benefits to weatherization. The benefits of weatherization is a topic that E4TheFuture is also taking on through a pilot effort in Massachusetts as reported in Healthy Indoors magazine Vol 5. No. 7 October 2017. Healthy Indoors Magazine has reported extensively on the issue of radon. One publication that caught my attention was a World Health Organization report (see the August 2016 issue). And, one of the most compelling statements from this report that stuck with me is: “There is no known threshold below which radon exposure carries no risk. The lower the radon concentration in a home, the lower the risk.” (The EPA standard is 4 piC/l.)
Oh My! what is the Home Performance Contractor to do? At least, this is the question that has been nagging at us and it is helpful to know that we are not alone.
After a lot of debate at our company, we have settled on two principles to guide us. First the Precautionary Principle ("When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.") and secondly, Risk Management (“the forecasting and evaluation of financial risks together with the identification of procedures to avoid or minimize their impact”).
We have a responsibility first and foremost, to alert our customers of the potential of harm. Our work routinely involves warning our customers of potential dangers. Why should radon receive a special exclusion? Radon is hazardous to our health. If this issue is being studied by qualified institutions of research and science (like say the EPA or the WHO) and they are expressing their deep concerns, don’t we have a duty to share this information with our customers? The health risks of exposure to radon are not debatable, in our opinion. As we see it, the issues for us in Home Performance are: Are we making it better or worse for the people who are living in the homes we work on? And, equally important: Who gets to decide this issue and assume the associated risks – us or the customer?
We have adopted a policy that allows the customer to have their home tested before and after weatherization (at no cost). We provide them with an EPA approved booklet and we strongly recommend that they do this testing. Whether they want to proceed with mitigation or not is their choice, but our contract requires them to waive any right to hold us liable for their choice now or in the future. (BTW: we do not install radon mitigation systems; we are provided the test kits by a contractor that does.)
We don't know yet if we have opened a Pandora's box, but we are somewhat confident that our customers will appreciate that, where their health and safety is concerned, we will err on the side of precaution. We also think that our approach is prudent in terms of risk management. Are we likely to lose some business as a result? Yes, I think that is a reasonable assumption. Could any business loss be recouped by being regarded as mindful of the customer? Perhaps.
Ultimately and presently, this decision is more an act of individual conscience. As such, if other contractors believe that the radon issue is a hoax, their consciences will probably dictate a very different course of action. We also think the choice is the customer's with respect to how much exposure should be considered safe.
The issue is vastly more complicated for program administrators at international, national and local levels and I believe they are struggling with how to come to terms with this too.
Note: We intend to collaborate with other radon stakeholders to collect data that will add to the growing understanding of this issue.
Kevin, I was recently made aware of a death in North Dakota that was directly contributed to radon exposure. Please follow this link for details:
Kevin, Here's another link to the reported radon toxicity death in North Dakota. Follow this link: