At RadonCare, we’re often asked about where the radon mitigation system discharge requirements – why here? We love this question. Why? Because getting it right makes a big difference for both performance and peace of mind.
Here are the most common questions we hear (and our honest, no-panic answers):
Where Should My Radon System Discharge?
We typically recommend a sidewall discharge whenever it meets code. Why? It’s:
- More energy-efficient in Canadian homes,
- Easier to service or inspect, and
- Better for protecting the fan from cold exposure.
Roof discharges are still code-compliant, but they can expose fans and piping to harsher temperatures, complicate installation, and increase the risk of freezing-related issues.
See the side wall discharge and roof penetration discharge study here.
Why Is the Fan Installed Inside of Homes In Canada?
In Canada, radon fans must be installed inside the home, often in basements, mechanical rooms, or conditioned attics. This isn’t a mistake; it’s a cold-climate advantage. What are the radon discharge requirements?
In the U.S., exterior fans became standard decades ago when radon mitigation first adapted HVAC inline fans not designed for airtight systems. There was concern about radon leaking out of non-sealed units, so placing them outside was the “safer” choice.
But now? We have radon-specific fans designed for sealed systems, moisture resistance, and long-term performance and Canadian code reflects that.
See the cold climate discharge study here.
Will the Radon Come Back Into My House? Or Into My Neighbour’s?
It’s a great question and one Health Canada has naturally studied in depth.
The short answer: No, it won’t.
The slightly longer answer: Radon dissipates extremely fast outdoors. A 2020 Health Canada field study confirms that radon levels drop to background levels within a few feet of the discharge point, even in low-wind conditions.
See the Health Canada study here
Plus, C-NRPP certified mitigation professionals follow strict clearance guidelines to prevent re-entry or risks to nearby occupants. These include:
- 1.0 m from openable windows or doors
- 2.1 m above public sidewalks
- 1.8 m from fresh air intakes
Want the full list? Check the clearance table here or view the C-NRPP homeowner FAQ
What About Water or Ice Building Up At the Discharge?
Another great one. Clients are often concerned that the air coming out of the radon system – which is pulled from below the slab – will cause water or ice to collect at the discharge point.
Here’s the reality:
- A properly sized and continuously running radon fan prevents condensation buildup.
- Air is constantly moving, which means no standing moisture to freeze.
- We install using smooth-walled pipe and avoid discharge angles that would trap water.
In short if you have a concern with your exhaust point we’re happy to help.
Could I Still Choose A Roofline Discharge?
Yes, but we generally recommend roof discharges only when sidewall clearances can’t be met. While still code-compliant, they come with several drawbacks:
- They require piping through upper floors, attics, or soffits – increasing installation complexity
- They’re harder to access for maintenance or inspection
- The discharge point is exposed to the elements, making it more prone to ice, snow buildup, and clogging
- And most importantly – they create more opportunity for roof penetrations to leak over time
If a sidewall discharge is feasible and meets clearance guidelines, it’s almost always the better choice in Canadian homes.
See the side wall discharge and roof penetration discharge study here.
General Discharge Point FAQ
Q: Will this affect the appearance of my home?
A: We install cleanly and discreetly. We use professional grade diamond core bit drills, not percussion style bits and do not need to mount the drill into your siding. Our exhaust points are clean and tidy and can be installed on any type of siding. Decorative rock, vinyl, Hardie Board – we can make it work!
Q: Is the air dangerous to walk past?
A: Nope. Radon gas outdoors disperses within seconds. You can continue to use your yard as you previously did.
Final Thoughts:
Your radon system works 24/7 to keep your home’s air healthy. A properly located, code-compliant discharge point is a big part of that and our team at RadonCare is here to make sure it’s done right. Want to learn more about how are systems are designed? Check out our page on mitigation design, Pressure Field Diagnostics page.
Have questions? Just ask. That’s what we’re here for.