Will portable home air cleaners reduce radon?

No. A portable home air cleaner will not reduce the radon in your house. Radon is a gas that seeps up through your foundation, and an air purifier filters dust and particles, not gas coming in from the ground. To actually lower a radon level you need a radon mitigation system, which 603 installs starting around $900 to $6,000, and most homes land around $1,950 to $2,250.

Here is why the air cleaner falls short. Most portable units pull air through a HEPA filter or a carbon pad. Those catch pollen, dust, smoke, and pet dander. Radon is none of those. It is a colorless, odorless radioactive gas, and it keeps coming up from the soil under your slab every single day. You could run a purifier in every room. The gas would still be entering faster than any filter could ever touch it.

Radon does not sit still either. It comes up through cracks, through the floor wall joint, through the gaps around pipes, and through dirt or fieldstone in a crawl space. A box on the counter can only move the air right around it. It cannot reach the source. So the number on your radon test does not move.

The EPA action level is 4.0 pCi/L. At 4.0 or higher, you should fix it. The EPA also says to consider fixing a home that reads between 2 and 4 (EPA, epa.gov/radon). New Hampshire has plenty of granite bedrock, so high readings here are common. Our radon guy Branden (we call him “B-Radon”) sees it all the time across NH, Maine, and Massachusetts.

The fix that works is active depressurization. For a normal basement with a concrete slab, that is a sub-slab system. We seal the obvious openings, set a pipe through the floor, and run a fan that pulls the radon gas out from under the slab and vents it up and out above the roofline. For a dirt or fieldstone crawl space, we use sub-membrane depressurization, where the suction pulls from under a sealed membrane on the crawl floor. Either way, the radon is leaving before it ever reaches your living space. A filter cannot do that.

You do not need a fancy purifier for radon. You need to stop the gas at the source. That is the whole job.

What a radon system costs and what drives it

Radon mitigation with 603 starts around $900 to $6,000, and most homes land around $1,950 to $2,250, and a radon test runs $50, credited toward the job if you move ahead. What moves the price is the layout of your house. A walkout, a finished basement, a slab versus a dirt crawl, where the fan can vent, and how many suction points the foundation needs all factor in. A simple slab is usually the lower end. A fieldstone crawl with a membrane is more work, so it sits higher.

We give you a free inspection and a free estimate, and you get a quote within 24 hours. If financing helps, we offer it through Hearth, subject to approval, and we make nothing on it.

Our radon mitigation carries a 10-year warranty. One thing to know up front. We do not guarantee a specific radon number unless we put that in writing. After we install, the post-mitigation retest is your job, and that is normal. Re-testing confirms the new level for your own records.

If you only have a basement water problem, that is a different system. Our Forever Dry System keeps a basement dry for life. Radon and water are separate fixes, though we often spot both during one visit. A wet basement and a radon problem can live in the same house.

You can read more about our radon mitigation work, our crawl space services for dirt and fieldstone crawls, and what stands behind every job on the 603 guarantee. If you are dealing with a damp basement on top of radon, see basement waterproofing. For the science and the action levels, the EPA radon program is the authority, and [verify] for the New Hampshire DHHS radon page if you want state-specific guidance.

Book a free inspection

Got a radon reading you are worried about? Call us at 603-610-1770 or book your free inspection. We will test it, explain it in plain terms, and tell you exactly what your house needs. No filter sales pitch!

Related questions

Does opening windows lower radon? It can drop the level a little while the windows are open, but it is not a fix. Close them and the radon climbs back. Cold NH winters make open-window living a non-starter anyway. A sealed mitigation system is the real answer.

Can I just seal the cracks myself to stop radon? Sealing cracks and the floor wall joint helps a system work better, but sealing alone rarely brings a high reading down to safe. The gas finds other paths. Sealing plus active depressurization is what lowers the number.

Will a radon system also help with basement moisture? A little. A sub-slab system pulls some damp soil air out from under the slab. But it is not a waterproofing system. For a basement that floods or sweats, you want the Forever Dry System, which is built for water.

Do I need to retest after the system goes in? Yes, and that retest is the homeowner’s job. It confirms your new radon level in writing for your own records. We install the system to vent the gas out. The follow-up test is on your side.