A call to action: Over the course of this coming year, let us conduct a field study by allowing US radon contractors to install 150 or more residential radon systems that vent at ground level.

We (the radon contractors in the field) could initially use only the most conservative of clearance guidelines when choosing (signing up) these homes for the field study.

These homes could not be part of a real estate transaction, for the contractor will need to maintain contact with the homeowners for initial and follow-up testing.

As with the Pennsylvania Re-entrainment Study, the radon systems could be set up to allow for extending the vent pipe above the roof line at the end of a year if the home owners desire or the follow-up testing indicates that it should be done.

We would need to design a study agreement that would hold contractors harmless during and after the study that would be acceptable to our insurance companies. I bet that the Pennsylvania study would have a model.

We would have to seek permission from state radon programs that have licensure.

If I have to return to a home at the end of the study period to run pipe up the side of the house, I will take that cost on.

At the end of a year we would have a good would have a better sense of how well the system perform across the country.

Colin: Thank you for your perspective. However, allowing US radon contractors the option to vent at ground level would not prevent them from using current guidelines for venting above roof lines. I can think of many cases where ground level venting would not be appropriate, especially in city centers with tight alley spaces between buildings. Also, as you mention. if you are concerned about noise, venting at ground level might not be appropriate.

I can also think of many cases where I was forced to run exterior pipe 30 feet of outside wall for no good reason. There were no exterior doors, windows, wall penetrations nearby. The fan was well away from other homes. I don't believe in these situations that adding extra length of pipe above the fan helps a smaller fan run more efficiently.

I appreciate your regard for properly sealing where you can and choosing a properly-sized fan for the home, but I see the issues of ground venting and fan diagnostics as being separate issues.

Ryan: I appreciate your respect for the Scientific Method (a la Karl Popper): we must continue to challenge our assumptions about radon re-entrainment and all other facets of our field. But I also believe that we should not hesitate to make informed choices and take action when the existing research and current practice (as in Canada) directs us to a logical course of action.

Are we going to act, or are we going to do more studies?

I say we should do both.

Ryan: Thank you for the research. It appears to validate Bill Brodhead's research and that of Canadian researchers.

All of this research compels us to update our standards so that our mitigation practices are science-based and ultimately benefit the consumer.

Is there anyone out there in favor of keeping the current standards and adding the newly proposed standards for venting residential radon systems above the roof line? I would appreciate hearing a cogent scienced-based argument why we should continue this practice exclusively.

Otherwise, I think we should begin defining the specific circumstances and site conditions where a radon contractor would be allowed to vent a residential radon system at or near ground level if they should choose to do so. For example, if there is an area on the side of a house where no doors, windows or nearby residences are present within 30 feet.

Or maybe we might just adopt the Canadian guidelines.

Thank you for the information, Shawn. I am not sure that we are comparing apples to apples when we compare exhausting combustible gas appliances with radon systems venting. However, it is interesting how similar the Canadian guidelines for venting radon systems at ground level are to guidelines for venting high efficiency water heaters and furnaces at ground level.

How do we shift the US Paradym away from running vent pipe up the side of a house to a more cost-effective, better practice of direct venting at ground level? About 1/3 of our standards are based on the assumption we have to run our vent pipes above the roof line.

If it is not necessary or advantageous to add 20-30 feet of pipe at the end of our air-flow systems, why do we continue to do so? Is this practice not somewhat insane?

Are we so entrenched in our standard-writing process and the momentum of our industry's past practices that we cannot see and acknowledge the obvious?

The new proposed standards suggest that we need better document our mitigation processes. The above posts quite effectively explain why. I would support the logic and science behind these proposals if only we were consistent in our logic and science regarding direct venting at ground level. I am sorry, but we cannot act logically on the one hand and illogically on the other.

I challenge my fellow mitigation contractors and our standards writing committees to address this cornerstone issue once and for all. Please correct me if I am wrong, but if direct venting at ground level is best practice, it would be absurd to continue with our current practices.

Colin,

I enjoyed reading the Canadian Professional Contractors Guide. You asked what we actually measure in our diagnostics since we do not have an official design guide. First off we tend not to take stack affect into our calculations. I guess in colder regions that would be more of a concern. I am on the Ohio/Kentucky border. Many of my past clients have radon monitors at home, and they do not report dramatic seasonal variations in radon levels in their homes. I have retested one home every two years over the course of 12 years and the radon levels have always been within .02 pCi/L of the original post mitigation level of 0.8.

Our design processes tend to be based on what instructors like Bill Brodhead teach us: With any older home or any home I any questions about, I always careful to use the appropriate fan for the substrate I am mitigating; I try (maybe not hard enough) to use just enough fan to move or manometer a couple notches left of zero under the slab so that I do not waste energy with an over-sized fan: I seal where we can; I attempt to verify the PFE once the system is up and running.

None of my systems have ever failed because I did not write down the sub-slab pressure at the end of the job. They failed because I did not treat a radon source in the home. Once I discovered that source and treated it, we were good to go.

Most of the homes that I have mitigated come in at 1.7pCi/L or lower, quite often below 1 pCi/L. In the last 20 years I don't recall ever settling for a post mitigation level of 3.0 or above. I am also a home inspector. I have tested a good number of homes with radon systems in my area, and I am always surprised how well they do even if they are not installed according to the strictest of state guidelines.

Back to my original question. It appears that there is no good reason for not venting directly at ground level. If this is the case, why do we continue to run vent pipe above roof eaves? Is there a joy in climbing ladders that I have not discovered? That question, to me, is worthy of our time and fundamental to what we are doing, if we want to be science based and open to new ideas.

Thanks Jesse and Colon for the information on the Canadian Professional Guide.

Hi Colin,
You describe an interesting contrast in radon industry cultures that may reflect a contrast in Canadian and US cultures. Canada has a much stronger national identity, so it is easier to mandate a national design process for choosing a properly sized fan for a radon job. The United 50 States of America have fifty different approaches to addressing the issue of radon. There are varying levels of standards enforcement among the states, and levels of enforcement can change with the political winds.

In the States, radon companies tend to be smaller mom and pa businesses. We are not engineering firms. As you mentioned, we tend to compete on price and volume, so we tend to wince at new mandates that may not be enforced. Sometimes we feel that many of the new mandates are not backed up with science or cost/value assessment.

It may be that because our systems are relatively inexpensive, more are installed per capita in the US than in Canada (I'm guessing.) I cannot imagine many of my fellow Americans spending $2-3K on a basic radon system. I cannot imagine how expensive a radon system would be that incorporated a crawl space and adjacent upper slab to the system. Ironically, American radon systems may be less energy efficient but more effective overall because of the volume of systems installed. The primary goal of a radon system is to save lives.

Most American radon contractors know how to perform pre- and post-mitigation diagnostics. We use them when we approach a more challenging home. We tend not to use them on a 20-year-old square box foundation in a neighborhood where we have previously installed radon systems. We do tend to wince about having to do extra paperwork that so many of the recent mandates require. Engineers and engineering firms tend to love to do paperwork. It justifies their actions, costs and credentials. Small businesses tend not to have the time or resources.

I think the members of AARST need to think twice about each and every new standard that we try mandate. The more we regulate our industry, the more expensive it becomes for the small business and the more advantageous it becomes for the larger radon/soil gas mitigation firms who already have the regulatory resources built into their business infrastructure. If we are not careful, we will have a radon industry that is closer to the Canadian model: an industry with less contractors and more profit for per job at the expense of consumers.

Colin, I appreciate your comments, though I use them to make a different point. I still have to ask if anyone has done any research as to whether the Canadian practice of venting radon systems at ground level is any better or worse than the US practice of venting above roof eaves?

Before we take on any new standards, let's verify whether we have to run vent pipes up the sides of homes in the first place. The Canadians do not. Instead of shooting from the hip, let's do valid research to verify which standards are necessary and which standards are just the latest machination of a standards writer.

Does the upper house structure truly match the foundation footprint? 3' x 10' crawl spaces can be hot spots and easy to miss.