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 have been finding more to support the idea that Radon is a tempest in a teapot.
I found the following article and discussion interesting.
The take away that I got from these is that mitigation is usually not necessary and is encouraged by an industry trying to justify itself.
This first is a discussion by industry professionals:
This article is a scientific perspective:
I have no links, just some anecdotal evidence. I ran several Blower Door Tests on my own home. So I know what the leakage was. After I tested for Radon, 10 pcl I thought about not mitigating. I also thought about mitigating just before the time of sale. I decided to spend some money now, instead of leaving it to my wife later to figure out. We have been here 30 years and have another 20 to go. My post test was 0 pcl.
I ran some blower door tests after I installed the system; with the fan going and without it going. The change in the Blower Door fan flow, with single point or multi-point testing, was not noticeable. It did not change the HERS Rating. The fan mentioned in one of the links below called 21 watts on the fan draw. Over a year that is less than 9 KWH. At 15¢, I can afford $1.35 annual. That will not change the HERS Index either.
If you read the RESNET/ICC/ ANSI Standard 380, it calls for the house to be set to winter conditions before running the blower door. Doors and windows shut. The Radon Fan will run in winter conditions. That should not impact the HERS Score either.
My observation is that Radon testing and mitigation is a fact of life at Real Estate Sales. The agents will recommend the test. They will push their buyer to have the seller remediate or walk away. I am aware of one house on the market for 2 years, because the owner will not allow the test to be run, much less remediate. Several large RE firms will not take her listing. This is a Zone II Radon area. Only 1 in 4 homes.
You may or may buy the science, when you decide to sell, you will test and then mitigate as needed. Or not sell and let your heirs handle the problem.
Thanks for the information. Very good empirical data. While I agree that running the fan won't cost much or change the HERS score. I just question is it necessary in the first place. I also just wonder if sellers and buyers are being held captive by Real Estate and Mitigation folks for monetary rather than health reasons.
So, is it, that it doesn't matter if Radon really isn't that dangerous, But, if you want to sell, you do what we say.
The Nay side is well represented with the links already posted.
I presented a neutral side, with the argument about time of sale issues.
The Yea side is well represented, but will not show up here, due to folks accepted the science the EPA and State Radon agencies have developed. The largest acceptors of that science are homeowner that pay for the mitigation systems.
Folks may pause before spending money to save money with energy efficiency improvements. They will pay money to improve comfort. They will pay money to remove a health hazard from their home.
I believe that there is a plethora of studies to support the dangers of Radon. I was a radiation specialist in the Nuclear Naval Submarine Service and I have a degree in physics. I understand the source and mechanism of Radon. It is a long term affect and is cumulative. Each atom of radioactive Radon gas that enters your lungs has a short half-life and will likely decay to other radioactive elements, as well as giving off alpha particles. Alpha particles are the most damaging type of radiation for close proximity. An alpha particle is the nucleus of a Helium atom, but without any electrons. Both its relative mass and its electrical charge will damage one or more lung cells. Keep repeating that and you not only have lung cells that are damaged, but you are setting up conditions for the cells to reproduce in uncontrolled fashion, or lung cancer.
Do take Radon seriously. Don't guess, test!
John, thanks for the information, it was very helpful.
Thank you Andrew, Ray, and John for sharing the information and links!
It seems to me that a newly-constructed home with a proper vapor barrier installed below the slab would greatly help reduce radon infiltration into a home. How has more modern construction practices, such as building code changes and energy efficiency codes, made a difference in radon infiltration into a home?
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.