• Randy Weestrand
    Some winters we have no calls regarding freeze ups. It usually takes a few days of -20F. Our current cold spell has been unusually long (2 weeks) but not severe (average temps -6F to 6F).

    I’ve taken 33 freeze up calls over the last week or so. After confirming they have an outside system, they get the standard talk: “Water vapor and droplets freeze… it will open up in 1 – 3 weeks…the fan is not moving air, which means it’s not doing any work which means it’s really happy and will run forever like this…don’t worry… the danger of radon is long term exposure... In fact, if you called Health Canada and said ‘My three day radon test is 8, what should I do!?’ you’d be told ‘Re-test for 3 – 12 months and then call us’”. The standard client response is “OK”.

    This raises a couple questions:
    1. Would the clients above have said ‘OK’ if there was an alarm sounding?
    2. Is it in our client’s best interest to sell them an expensive solution (heat tape) to a short term self-correcting problem that is not a health risk?
    3. Our wise and prudent neighbors to the north tell their citizens “Health Canada recommends long-term radon testing to determine if the radon concentration exceeds the Health Canada Guideline level of 200 Bq/m3. A test duration of at least 3 months is recommended, and 12 months is optimum.” In other words: The risk of radon is long term exposure. Put a decision to mitigate on hold for 12 months! Elevated radon does not require an immediate response!!! WHY ARE WE EVEN DISCUSSING INSTANT FAN FAILURE ALARMS!!! (Sorry for shouting. This gets me a little agitated.)
  • Stan Plowden
    What I don't quite understand about the "mandatory" Radon System Alarms is that WHY is the warranty on them only "2 years" when most fans are warranted for FIVE? I personally see that benefit of "traditional electronic alarms" in homes where builders installed passive piping (but only thought of it as "piping required to be installed because building code required it). The vast majority of builders who install this piping "assume" that it will take care of the radon under the slab because it allows it to "rise and exhaust" like helium does! But WE know that radon is "heavier" than air and must have a "vacuum" to draw it out. My county building code requires passive pipe and they even provide an "EPA schematic" of slab and crawl space systems. Each reference a "warning device". However, NO builder makes any sort of provision for that. So when a house is later tested and elevated levels are found and a fan is installed, there is no way for the "future homeowner" to check and see if their fan is working without out climbing up to the attic! I, personally, like the manual manometers because you don't have to depend on "electronics" for them to work. We all know how power strips, modems, routers and TV's get "fried" due to line surges (or lightning). So I have a had number of homes that I "opened up the wall" in front of the pipe and installed a manometer on them with a window/door in the dry wall. But I will admit this is usually only done in closets or areas of the home where "cosmetics" don't matter. Who wants a see-through door in a living room wall?
  • Robert Burns
    9.3 Fan Location
    In the early days of radon mitigation, prior to development of the US mitigation Standards, the fans used were not airtight, and leaked some of the exhaust air from their casings. A variety of ducting materials was also used and not all joints were airtight. As a result, best practice was to place the fan and discharge piping outside the building envelope. The interior piping was then under negative pressure, so neither fan nor duct leakage would enter the building. Fans located outside the building envelope are required by US mitigation standards.
    In-line centrifugal fans specifically designed for radon mitigation are now available. Some airtight fan designs are available with sealed joints; some have the casing joints and electrical connections located on the suction side of the fan, so leakage from the fan is not a concern. Plastic plumbing pipe is now used routinely for the suction and exhaust ducting, with airtight solvent welded joints in the piping and airtight rubber plumbing couplers to the fan.
    As properly installed fans and ducting will not leak soil air and radon into the building, the fan no longer needs to be located outside the building envelope, but can be mounted inside the building. If this is combined with a grade level discharge, almost the entire system can be inside the thermal
    envelope. In cold climates, this eliminates concerns about condensation or frost in the fan or piping, as only a short length of discharge pipe outside the house will be exposed to colder temperatures.

    Canada has kept up with the science. Perhaps we need to look to them for solutions to problems we have created.
  • Doug Taylor
    The more I look into this, the more disturbing it becomes.
    As the need to keep adding "crap" to the system to meet new regs. After looking at Bill Brodhead's paper on ground level exhaust and Canada's allowing ground level exhaust...why are we not walking this back and calling for ground level exhaust and a Radoneye monitor. No need for an alarm, manometer, heat tape, exhaust stack, extra pipe, pipe hangers, and increased w/c rates due to ladder work above 6 feet. Are we looking at the science and or are we looking at who can benefit from selling parts to mitigators??
  • Bill Brodhead
    Doug. Thanks for the reference. I don't think many people saw my 10 minuted allotted time at the last virtual radon conference about measuring ground based exhaust as the Canadians are allowed to do. When I looked into the research that both methods were based on I realized our exhaust at the roof requirement was based on research done in PA 30 years ago that was partially or primarily due to ground exhaust vented parallel to the siding. This lead to my extensive crm measurements of ground based exhaust at one house last summer. Being self funded research and requiring complete homeowner cooperation it of course had to be my own house so it is a one house study. Included is the link to the overview of the research and there is a link to the full paper on the web page.

  • Bob Wood
    Doug I agree with you. Reasonable Profit is not a dirty word. In Canada our pipe from the wholesaler is about 60-70$ per 12 foot length. but all of our fans ECT comes up from states and while there is a cost to crossing the border with materials with good management of this you can keep costs down. Our typical systems go for about 2160.00 US plus taxes or 3000.00 CAN. At that price point you are reinvesting most of profits in company to cover depreciation of capital assets and marketing to bring in new revenue streams. We routinely travel up to 5hrs drive (one way) to service new and repeat customers. To get down to the 1500.00 US I would be out of business. Maybe that is why 50% of US mitigators are in business for less than 2 years. The low price may be why mitigators are driven to install SDR 35 above grade inside the building, not do communication testing to properly size the fan, and alarm calls are a significant hassle.
  • Doug Taylor
    Bill, your paper was excellent and I would hope everyone takes a look at it. Looking at the AARST “May 2014 Position Paper on ASD Discharge” this issue obviously has been around a long time and I’ve not yet seen the science behind the “position”. Many years ago when I was an Sr. Environmental Engineer at VA DEQ and TN TDEC in their air programs, the old saying was “The solution to pollution is dilution” which at one time led to taller and taller smoke stacks. Of course we now know that’s not the only answer, and with the ability to accurately test and model the stack exhaust/plume we can design better more efficient systems. The AARST position is similar to “if a tall stack is good...taller must be better”. I think we are better than that, AARST (Dallas) what’s it going to take to put together a complete study on this? Bill presented a self funded study which supported a hypothesis which honestly most of us have had since we installed our first systems.

    Bob, 5 hours one way...that’s dedication! We have been doing radon and vapor mitigation for the past 15 years, and yes we have seen many mitigation companies come and go (and fixed alot of the junk they installed). Like you, we could never make it on the $800-1500 rates that SOSRadon and other sites so easily quote. But, what I am questioning is why these sites have not been updated? It is misleading for people to think their radon issue is going to be fixed for 800 bucks in most cases. If they think the fix is $800 and their first quote is $2500...of course now they are going to get 4 more quotes, waste everyones time bidding a simple radon system and possibly won’t even put the system in because they budgeted the $800. My point is, in order to support the mitigation business model, we need to ensure the public has reasonable expectations of cost and quality.
  • Bob Wood
    Doug and All: I agree completely that public expectations of cost must be continually updated, it must be very frustrating to hear on a repeated basis.......... but I read on the internet that SSD systems cost only $ 800.00.
    About the side wall discharges and fans indoors that we do in Canada. I would agree that this is a model that cold climates may want to look at in code and can be easily codified by using ASHRAE climate zones such as this map https://www.google.com/url?sa=i&url=http%3A%2F%2Fwww.iaqsource.com%2Farticle.php%2Fashrae-climate-zone-map%2F%3Fid%3D194&psig=AOvVaw2oZX55PjIFZmiKiuoYFPKS&ust=1614436802821000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCLCl9_Tjh-8CFQAAAAAdAAAAABAD
    As we in Canada have been installing sidewall discharges with tradesman doing the work and they work well with little or no re-entrainment, and we use significantly less distances to building openings (12" min and 36" recommended) than you do in the USA.

    I did my first field install yesterday in 1 1/2 years when we had a mitigator go out sick at last minute ........... my helper had been on 8 previous mitigations and he has completed the measurement training but not the mitigation training. It was obvious that he had not grasped the concepts of communication testing and what the numbers meant for fan sizing. It is not a concept that is easily teachable to many individuals but, it is critical to ensuring that the fan is rightsized for the building. Rightsizing the fans means that building air is not being stolen by SSD system that will cost the building owners 1000's of dollars over the next 5 -10 years.
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