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've read this article, too, and found it very informative. I now do not consider radon a major issue, certainly not at typical residential levels.
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!
It's good to see somebody who has some REAL scientific knowledge commenting on the real danger of radon. I was required to take MANY HOURS of training on radon properties & dangers, and I am convinced of the dangers. The cost is negligible, both installation and operation. The levels, if properly mitigated, and not later compromised by basement "waterproofing" or other modifications to the structure, will not be affected by efficiency measures. The realtors would all love to see the radon situation disappear; it's one of many possible "deal killers."
The dangers of Ionized radiation is known but the issue is at what level does the damage become an issue.
I spent 20 years in Biotechnology/Immunology working with radioactive materials and wastes so I have a bit of dog in the fight so I really want the best information. Cell damage is happening all the time from many assaults. We know what large doses can do but when we get into lower levels of exposure it is not clear.
The question is the LNT (linear no threshold) hypothesis that is the crux of determining the dangers of low-level exposures and this is where the waters get murky.
Most of the major studies are based on the initial BIER studies with uranium miners as a baseline. It has been my observation that many of the studies have some underlying factors that make them difficult to extrapolate some of the data. I am not a statistician and wish I had a better understanding of how they remove bias and confounding factors in these studies.
From the International Atomic Energy Asso-
"low doses of radiation, there is still considerable uncertainty about the overall effects. It is presumed that exposure to radiation, even at the levels of natural background, may involve some additional risk of cancer. However, this has yet to be established."
Here is an article from the NIH that actually tries to state there is a hormetic effect, which I personally am a little iffy on also, but just shows how murky the information really is.
The 4 pCi/L action level still seems like an arbitrary number based on some assumptions that are just guesswork on costs and effects.
My biggest issues are the numbers attributed to radon-induced lung cancer. These numbers are pure guesswork since it is based on yet to be firmly proven Hypothesis.
When we get into these low-level dose environments there can be confounding factors that can skew the information one way or another. I guess I am just being a skeptic and I am just waiting for what I think is proper irrefutable proof related to low-level doses.
We should be looking at all the available data though.
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?