How many decibels is a radon fan?
A radon fan spans 50 to 75 dB on Festa's estimates, from "50-55 dB" for its quietest AMG fans to "70-75 dB" for its Extreme models and the Fury. Suncourt rates its RDN04 at 59 dBA.
Festa's product pages give these estimated ranges, each followed by "(can vary depending on system configuration)":
- Phoenix EC, Phoenix ECS and Triumph ECS: 50-55 dB
- Surge EC and Surge ECS: 50-60 dB
- Maverick, Hawk and Spirit: 55-60 dB
- Triumph EC: 55-65 dB
- Maverick EC, Hawk EC and Legend: 60-65 dB
- Maverick ECS and Hawk ECS: 60-65 dB at maximum speed
- Eagle: 65-70 dB
- Prowler: 65-75 dB
- Eagle Extreme EC, Legend Extreme EC and Fury: 70-75 dB
Festa's own blog post on fan noise puts the field in the same place, saying most properly working radon exhaust fans "produce between 50 and 75 decibels". None of the pages names a distance, a weighting, a flow point or a test, so we use the ranges to order Festa's fans against each other and for nothing else.
Festa and Suncourt state radon fan noise in different ways. Festa gives an estimated range in plain dB that moves with the install, and Suncourt gives one A-weighted value plus a loudness rating in sones.
Suncourt's RDN04 data sheet lists 235 CFM, 91 watts, 59 dBA and 4 sones in a single performance row. It does not say where the microphone stood or what static pressure the fan faced. Sones are a separate loudness scale, and our sones and decibels explainer sets out why a sones figure never shares a ranking with a decibel one.
So the RDN04's 59 dBA is not called louder than the Phoenix EC's 50-55 dB, nor quieter than the Maverick's 55-60. It sits in its own group, which is why it carries no rank among the Festa fans.
Are EC radon fans quieter than AC fans?
No, EC radon fans are not quieter across Festa's own line. The Phoenix EC and Triumph ECS hold its lowest estimate, 50-55 dB, but Festa lists the Maverick EC and Hawk EC at 60-65 dB, above their AC versions.
Motor type, by Festa's figures, matters less than which job the fan was built for. The Phoenix EC and the AC Maverick both serve 500 to 2,200 sq. ft. footprints on gravel and sit five decibels apart, the EC lower. The Maverick EC serves that same footprint and Festa puts it five decibels above the AC Maverick.
One pair that does not line up
Festa lists the Triumph EC and Triumph ECS with the same 370 CFM and 2.9 in. w.g., yet gives the first 55-65 dB and the second 50-55 dB. The only difference Festa describes is the ECS's built in speed potentiometer.
Festa does not say whether its range for the ECS assumes a turned down dial, so we pick the ECS on the number Festa printed and flag the gap.
What a speed dial changes
On the Maverick ECS page, Festa writes "Estimated dB Range: 60-65 dB at maximum speed" and adds "lower speed to decrease noise level". It is the one place Festa ties a range to a setting. No lower-speed figure appears for any ECS fan, so the benefit of turning one down is real but unquantified.
Does a radon fan run all the time?
Yes, a radon fan is built to run without stopping. Festa writes that the motor "must run all day, every day", and Suncourt describes its RDN04 kit as "MET listed for continuous use and indoor/outdoor operation".
That changes how a modest number reads. A kitchen appliance at 55 dB runs for an hour; a radon fan at the same level runs through every night of the year. Festa's soundproofing post names interrupted sleep and a disturbed home office as the usual complaints, particularly when the fan sits in an attic or directly outside a living area.
Can a radon fan go in the attic, a garage or outdoors?
Yes, a radon fan can go in any of those places. Festa says the fan is "typically installed in the attic or outside the home", though its Eagle and Spirit pages add "Not For Use In Unattended Areas".
RadonAway, Fantech and Suncourt list their fans for both. RadonAway's spec sheet says its RP fans are "ETL Listed for indoor or outdoor use", and Fantech's Rn2 sheet says the fan "can be mounted both indoor, outdoor and in wet locations". Suncourt's kit is listed for indoor and outdoor operation.
Placement shapes noise as much as the fan does. Festa suggests mounting the fan outside or in an unoccupied part of the house, in line with local building codes, and running vertical pipe through a hall closet rather than a bedroom closet. A garage wall or an exterior mount keeps the motor out of the attic above a bedroom ceiling.
Do radon fan mufflers work?
Yes, radon fan mufflers help with exhaust rush, by their makers' account. RadonAway recommends its Exhaust Muffler when the "rushing" sound of outlet air disturbs people, and Festa says its Diamond Muffler uses acoustic foam to change the noise's pitch.
Neither maker gives a decibel reduction for its muffler in the documents we read. Festa argues that pitch matters more than level, writing that "the frequency of the noise rather than the decibels is usually to blame", which is a claim about how the noise feels, not a measurement.
For vibration, both Festa and Fantech point to soft couplings between fan and pipe. Fantech sells LDVI couplings it describes as low durometer vibration isolators. Festa also warns never to wrap or insulate the fan itself, because that can lead to overheating.
Why do RadonAway and Fantech print no decibels?
RadonAway and Fantech print airflow, pressure and wattage for their radon fans but no noise figure. Both cite HVI certified fan performance, and HVI's directory leaves the "Rated Sound (Sones)" column empty for their radon fans.
We searched HVI's Section I directory for RadonAway's RP140, RP145, RP260 and RP265 and for Fantech's Rn2, Rn2 EC and Rn4EC. Each has certified cfm and watts at one or more static pressures, and none has a sones value. Soler & Palau's PRF-100 is listed the same way, and its submittal sheet has a sones column with no number in it.
RadonAway's spec sheet calls the RP series "ultra-quiet", and Fantech's brochure says its Rn 2EC and Rn 4EC "produce less ambient sound". Without a number from either maker, these fans stay out of the ranking.
Does a high suction radon fan make more noise?
Yes, a high suction radon fan usually carries a higher Festa estimate. Its Eagle, at 65-70 dB, and its Extreme models, at 70-75 dB, sit well above its gravel fans; the Surge EC is the exception, reaching 3.4 in. w.g. at 50-60 dB.
That makes soil the first question for a quiet system, not brand. Festa describes each fan by the footprint and sub-slab it suits, gravel or clay. A home on open gravel can use a Phoenix EC; one on packed clay may need suction that only Festa's louder fans provide, and a sub-slab test by an installer settles which.
The inline duct fan guide covers fans that move room air through ducts, and our quiet basement page covers the other machines that share a basement or utility room with radon pipe.
