"Our radon system is safe, yours is not"... "No, yours is outdated, ours more reliable and safer!" 

Written by Tom Francis, owner A Best Radon Systems and Fix Your Radon, February 2024

(For simplicity sake in this article, I'm using general terms when speaking of "American" and "Canadian" "type radon systems". There are many types of systems or ways to mitigate radon in both countries but I'm referring to the most common type of systems, currently installed, in existing homes with basements, in each country.)

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I became aware of the differences of radon systems in Canada and the US in 2017 when I got an email from a radon contractor in Canada regarding a blog post I wrote, titled, "Improper and Unsafe Radon Mitigation Systems." In which I pointed out several problems in a radon system installation from a YouTube video, that happened to be installed in Canada.

 

 

 

 

 

 

 

 

 

Two of the things I pointed out as being improper and unsafe were, the radon fan being located in the basement and the radon vent pipe which terminated outside, near ground level. Since I'm a graduate of Rutgers University's National Radon Proficiency Program (NRPP) certification courses for radon measurement and radon mitigation and a licensed NY State home inspector, I had been taught and was aware the installation location for both the radon fan and vent pipe termination were safety issues and not allowed according to the current radon mitigation standards. I was not aware Canada had a totally different set of often contradictory standards.

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In the above mentioned email, the radon contractor said "Yes I agree with you on all of it, except #1, while yes, the EPA does state that “The exhaust fan must not be located in or below a livable area” , Mike Holmes is Canadian, and the Measurement and Mitigation licensing body in Canada is C-NRPP, they teach in the courses that since we can not obviously put fans outside due to our way too cold winters, that it is in fact the standard in Canada to simply install the sub-slab depressurization system exactly the way Mr. Holmes did." And the C-NRPP also teaches that the radon vent pipe should, preferably, be terminated near ground level.

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So, I checked this out and this information was confirmed, the Mitigation licensing body in Canada, C-NRPP has radon standards for radon mitigation that are quite contrary to the American National Radon Proficiency Program (NRPP). I found this to be confusing and even troubling as I dug into the reasons for the contradiction of standards. Especially since the NRPP and C-NRPP were so closely linked. In the fall of 2012 AARST Radon Reporter states: The National Radon Proficiency Program (NRPP) opened a Canadian version of the credentialing program (C-NRPP).

 

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The major differences between these two types of radon mitigation systems arise out of the contradicting standards set by each countries governing agencies. It is interesting to note how the radon mitigation standards set by each countries radon mitigation governing The differences, simply put, are:

The original AARST American Association of Radon Scientists and  formed CARST

 

1) The Canadian type radon system recommends putting the radon fan inside home's basement for reliability and safety reasons - the American type radon system does not allow radon fans to be installed in basements for safety reasons so they are mounted on the outside wall. Additionally, for reliability and safety reasons the Canadian type radon system recommends the radon vent pipe terminates with the vent pipe extending up the wall to above the roof as opposed to the Canadian type radon system which has the radon fan mounted inside the basement with the vent pipe venting through the wall near the ground. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Above we see an example of the most common American type radon mitigation system. This was also the most common type of system in Canada prior to about 15 years ago. This American type radon system is basically comprised of a hole drilled through the basement floor with a PVC vent pipe secured to the hole; the vent pipe goes up and then angles out through the exterior wall usually a couple feet or so above the ground where the radon fan is mounted, and the vent pipe is routed up the wall and soffit until it extends above the roof. Care must be taken for the location of the vent pipe so as not not block windows or doors.

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This set of photos above, shows the Canadian type radon system. It basically functions the same as the American type radon system, but the components are placed differently. The radon fan is placed in the basement and the vent pipe discharges near the ground like a dryer vent. You can see there is a lot less pipe used.

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hich for the last +10 years has been the  recommended type of radon system for most homes in Canada. This is actually an upgraded and better version of the American type system. Canada used to follow the same radon mitigation standards put out by the US EPA back in 1994. The American type radon system experienced problems Canada's colder climate with extended periods of freezing weather s recommendation that radon fans to be installed in basements and to vent the radon air, near the ground is better. It may not be better in every situation but in the vast majority of homes, putting politics and contradicting standards and laws aside, it is better choice, hands down. Canadian type radon system with the radon fan located indoors is better in several ways, compared to an American type system with the fan located outside the house, especially in cold weather climates. Prior to 2010 most Canadian radon mitigators installed radon systems following the American Radon Mitigation Standards and most of those systems had the radon fan mounted on the exterior of the home. Canadians noticed that during extended freezing temperatures, ice caps would form on top of the vent pipes blocking the air flow and their radon levels went up.

 

When an ice cap forms, radon mitigation ceases because there is no air flow even though the radon fan continues to run. This poses a radon safety hazard as the radon will return to pre-mitigation high levels until temperatures warm up long enough to eventually melt the ice and the air flow is resumed. It could take days, weeks or months to melt before radon mitigation resumes. 

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How does that happen? The radon fan pulls warm moist air from below the ground which cools and condensates as it moves up the vent pipe. In freezing weather the air cools more and more the further it gets from the ground. The cooling moisture in the air condensates and collects as droplets as it comes in contact with the cold surface of the vent pipe and when cold enough the droplets freeze before they exit the pipe. The ice continues to form, building up and restricting air flow or totally stopping the air flow. 

 

 

 

 

 

 

 

 

 

 

 

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The freeze thaw process also takes a heavy toll on the service life of radon fans. According to my estimate from having replaced hundreds of failed radon fans, exterior radon fans in central New York have roughly one third the service life - 5 to 12 years, compared to radon fans located in a basement or attic space which last much longer, 20 to 30 years. I have replaced many dozens of exterior mounted radon fans from less than 1 year old to less than 10 years old. I have never seen an exterior mounted radon fan last for 20 years, however I have seen dozens of basement or attic mounted radon fans still operational after 20 to 30 years.

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Pros - Canadian Type Radon System (indoor radon fan)

• Indoor fan radon systems are safer due to being more reliable; they will not freeze up and stop working when it gets really cold.

• Indoor radon cost fans last about 3 to 4 times as long. Replacing a radon fan typically costs $250 to $500.

• Indoor radon fans are less expensive to operate, saving money on your electric bill.

• Indoor radon fan systems cost less to install. Typical savings of $100 to $300 or more due to less in materials and labor costs.

• Interior radon fan systems are much easier to maintain.

• Canadian type radon mitigation systems are much more aesthetically pleasing. No fan mounted on the wall and pipe running up the exterior to above the roof.

• Radon systems with interior mounted fans typically have more options for location of the radon vent pipe discharge since it is similar to a dryer vent. 

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Cons - Canadian Type Radon System (indoor radon fan)

• Indoor fan radon are much less common in central New York and many home owners, realtors and home inspectors are ignorant of the facts regarding Canadian Type Radon Systems.

• Uninformed persons often make false statements regarding indoor radon fans such as "Radon fans are not allowed to be in a basement", "they are illegal", "they are unsafe", "they are against code", "they are  not properly installed". Remember, these are false statements which could bring consequences.

• When selling a home with a Canadian type radon system for the above reasons, a radon fan located in the basement may be an issue if the well intentioned realtor or home inspector tells the buyer it is unsafe or against code and the fan should be moved to the exterior.

• In some cases the Canadian type system can be louder than an American system. There is very little to no noise heard inside the house with either type of system. In both types radon mitigation systems the loudest noise is at the discharge point of the radon vent pipe. If it discharges directly onto a deck or patio area, it would be louder than a pipe that runs up the wall two stories to above the deck or patio. Most systems are designed to discharge at one side or the other of the home where the small amount of noise is not noticed.

 

Pros - American Type Radon System (outdoor radon fan)

• In New York and the US in general, the American systems is what most people have seen and are familiar with.

• Less problems with realtors and home inspectors in the US when selling the home.

• The American type system is follows the American Standards of practice, this eliminates the contradiction of the Canadian standards and recommendations.

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Cons - American Type Radon System (outdoor radon fan)

• Outdoor fan vent pipes are vulnerable to freezing. If ice caps form the mitigation process stops and the radon levels will rise quickly inside the home to pre mitigation levels. This is a significant safety issue. The fix for this is seldom performed, however for a significant added cost, the exterior vent pipe can be insulated or replaced with a special insulated pipe.

• If the vent pipe extends above roof where ice and snow can slide off the roof, especially a metal roof, the pipe will be vulnerable to being broken off. I've had to make this repair often times (not systems I installed).

• The exterior mounted radon fan has about 1/3 the service life of an indoor radon fan.

• Operating costs of the system is at least three times as much. My minimum cost to replace a radon fan including parts and labor is $495. Outdoor fans in New York are replaced on average about every 8 years and fans mounted indoors every 20 years or more.

• Aesthetically less desirable. The exterior mounted radon fan and vent pipe extended to above the roof is more of an eye sore than a dryer vent sized exhaust vent. Many homeowner associations require the exterior radon fan and vent pipe to be painted the same color as the house.

• American type radon systems can be quite expensive, difficult and dangerous to maintain, removing from the wall to paint or when changing the fan, especially for vent pipes that extend up above a second story roof and attic space sometimes more than 30 feet.

• Some exterior mounted radon fans are louder, vibration can transfer from the fan and vent pipe to the wall of the home at attachment points sending the sound and vibration through the wall to inside the house. 

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Choosing The Best System is a Problem

Because of the Contradiction of Standards and Laws

There is a clear and direct contradiction between the Canadian and  American Radon Mitigation Standards. The Canadian government, Health Canada and the Canadian

 

 recommending radon fans be placed in basements and the second states radon shall not be installed in basements. The old and current American EPA and National Radon Mitigation Standards of Practice do not allow radon fans to be placed inside basements, below or in the living areas of the home for "supposed potential" safety reasons. In contrast Health Canada, Canada's agency similar to the EPA, recommends that radon fans should preferably, be placed in basements, typically in a mechanical room or unfinished part of the basement.

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Quote from Health Canada's Radon Reduction Guide For Canadians - "The sub-slab depressurization pipe can be vented at either the roof level or ground level of the home. The fan can be placed in the basement or an area outside of the living space such as in a garage or attic. If the fan is placed inside the living space of the home"

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In contrast the EPA's Consumer Guide To Radon Reduction states, "The exhaust fan must not be located in or below a livable area. For instance, it should be installed in unconditioned space" 

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Picture courtesy of Health Canada - Radon Reduction Guide For Canadians

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See video below: Canadian Mike Holmes, Canada's most trusted Home Inspector, pointing to a radon fan installed in a basement as an example of a properly installed radon system. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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New York State Requirements for Radon Mitigation Systems

As of this writing - 2/12/2024, New York State does not certify or license radon mitigators and there is no requirement for Radon contractors or mitigation firms to be certified or licensed. In fact, there is no state regulatory oversite regarding radon mitigation, meaning, homeowners or radon mitigation contractors or general contractors can install any type of radon mitigation system they like, as long as it complies with applicable local building codes. I've checked and there are no radon mitigation specific code requirements for Manlius, Fayetteville or Syracuse and there are none that I'm aware of in any other central New York locality.

 

 

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Other States Requirements for Radon Mitigation

Some other states do have require licensing and certification for radon mitigation, such as Connecticut, New Jersey and Pennsylvania.

See related message from the New York state radon office:

 

Click here too view full page:       "...New York State does not regulate radon service providers, however, certification through one of the national organizations is recommended."

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Misinformation Abounds in New York re Radon Mitigation 

Unfortunately in New York there is no lack of misinformation regarding radon mitigation, radon testing and radon in general. I have heard and am aware of many realtors, home inspectors and radon mitigation contractors who have repeatedly made false statements often opposite of what the truth is. Following  are some common mistruths often stated:

• Radon fans installed in a basement are against the law, or against building code

• Redon vent pipe that 

 

heard   what is required by NY State law, local codes, what is safe and not safe, what is proper and not proper, 

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What do the Radon Fan Manufacturers Say?

The three major radon fan manufactures were asked about how their fans performed when located outside in cold weather environments and any concerns or installation instructions that they would have. Here are their responses:

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Festa Radon Technologies Co: “Festa fans are rated for outdoor use. Festa has no concerns about our fans being placed outdoors in cold temperatures provided they are installed in a vertical position”

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Brief History – The Cowboy Days of Radon Mitigation

Canada actually followed the original American Radon Mitigation Standards, set by the EPA back in 1993. At the time, in the early days of radon mitigation, the EPA scrambled to put together some type of standards for mitigation of radon since contractors and homeowners were throwing together all type of things to mitigate radon including all types of unsuitable fans and improper vent materials. For example using flexible plastic dryer vent attached to fans using tape. Many of these cobbed together components fell apart in no time and became safety hazards. The EPA for the most part copied the Plumbing Vent Code intended for venting sewer gas and used that for the standard to vent radon radon gas. Today, in 2024 the American National Standards of Practice for Radon Mitigation have changed very little.

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An excerpt from Canada Health publication “Reducing Radon Levels in Existing Homes: A Canadian Guide for Professional Contractors” Section 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.

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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.

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A fan should be installed so that the flow is vertical, so that any condensation in the system will drain through the fan, rather than pooling in the casing. To reduce vibration and noise transfer to the building, it should be connected to the piping with airtight rubber plumbing couplers that hold the fan 1 cm from the pipe. If the supply and discharge pipes are firmly mounted, the fan can simply be attached to the pipes by the couplers without other support. If it is attached to a wall, a masonry or concrete wall will give lower noise than an internal framed wall.

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If the selected fan is not airtight, it must be mounted outside the building envelope. In cold areas, an outside fan is at risk from premature failure due to moisture in the exhaust air condensing, and freezing in the fan. To prevent this, a fan mounted on the exterior of a building should be placed inside an enclosure (commercially available enclosures are available) for cold weather protection. A condensation by-pass should be installed to collect and divert condensation in the discharge pipe around the fan. To prevent the condensate from freezing, the discharge should be led to the soil through an insulated pipe, or in very cold areas, back into the fan suction pipe. The suction pipe inside the house must be sloped so that condensate passing through the fan can drain back to the sub-slab fill with no low spots where condensate can accumulate.”

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Source Location: Canadian Radon Mitigators Installation Guide.pdf (wpb-radon.com)

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