# Best radon mitigation fan: RadonAway, Festa and Fantech fan curves compared by watts, suction and CFM, with the maker's own sub-slab guidance deciding which one replaces yours > Maker fan curves compared: RadonAway RP145 34-66 W, 81 CFM at 1.0 in. WC; GP501c 3.8 in. WC for clay; Festa Maverick 116 CFM. EPA says use a qualified mitigator. | | | |---|---| | Source | https://ownerspec.com/air/reviews/best-radon-mitigation-fan/ | | Publisher | OwnerSpec (https://ownerspec.com/) | | Published | 2026-10-11 | | Updated | 2026-10-11 | | Facts verified | 2026-10-11 | | Disclosure | Contains affiliate links. OwnerSpec may earn a commission at no cost to the reader. | --- ## Short answer The default replacement radon mitigation fan for a typical US sub-slab depressurization system on a 4 in. riser is the RadonAway RP145: RadonAway's 2023/2024 fan guide prints 34 to 66 watts, a recommended maximum operating pressure of 1.7 in. WC and 81 CFM at 1.0 in. WC, and its product page prints an ETL listing for indoor or outdoor use with a five-year limited warranty. RadonAway's own chart names the RP145 as the swap for a Fantech HP190, HP2190 or Rn2. On a porous gravel sub-slab the lower-power RP140 (17 to 21 watts, 0.78 in. WC maximum) or the Festa AMG Maverick (66 watts, 116 CFM at 1.0 in. WC) does the same work; on clay or tight soil the high-suction GP501c class (3.8 in. WC recommended maximum, 3 in. duct) is the one to look at. Skip every fan here if the house has no system yet: EPA's Consumer's Guide to Radon Reduction recommends a qualified radon mitigation contractor. ## Fact sheet - **Answer:** The default replacement fan for a 4-inch sub-slab depressurization system is the RadonAway RP145: 34 to 66 W, 1.7 inches WC recommended maximum operating pressure and 81 CFM at 1.0 inch WC per RadonAway's 2023/2024 fan guide, ETL Listed for indoor or outdoor use with a five-year limited warranty per its product page. On clay, the high-suction GP501c class (3.8 inches WC) replaces it, and EPA recommends a qualified radon mitigation contractor. - **Comparison basis:** RadonAway's 2023/2024 Radon Professional's Fan Guide (watts, recommended and maximum pressure, CFM at stated in. WC, duct size, series soil guidance, Fantech and AMG replacement chart), RadonAway's RP145 and RP265 product pages (ETL listing, UL 507, warranty), Festa's 2022 catalog (AMG Maverick, Eagle and Eagle Extreme curves, sub-slab guidance, warranty), Fantech's Rn2 spec sheet and 89052 catalog, and EPA's Consumer's Guide to Radon Reduction and Citizen's Guide to Radon for the contractor recommendation, fan placement, warning device and service life. - **Assumptions:** The reader already has a working or failed active sub-slab system with a U-tube manometer and knows the old fan's model and the riser's pipe diameter; Figures are at sea level; RadonAway's guide reduces recommended operating pressure by 4 percent per 1,000 ft of altitude; RadonAway's figures are from the July 2023 guide because the 2025 RP Pro spec PDF would not open; Fantech Rn4 and HP2190 numbers were not readable in any opened maker document and are left blank - **Method:** OwnerSpec compared manufacturer-published fan tables and product pages read on 2026-10-11 and confirmed each listing in stock the same day; it did not run, measure or install any fan, prints no health outcome, and reports only the figures the cited document states. - **Primary source:** [RadonAway, 2023/2024 Radon Professional's Fan Guide](https://www.radonaway.com/pdfs/radon-newsletters/pdfs/RA_2023_24_Fan_Guide.pdf) (manufacturer or vendor document) - **Facts verified:** 2026-10-11 - **Last updated:** 2026-10-11 - **Canonical URL (cite this):** https://ownerspec.com/air/reviews/best-radon-mitigation-fan/ If your U-tube manometer still shows two different column heights, the fan is running and this is the wrong page: read [how to read the manometer](/air/guides/radon-manometer-u-tube-reading-what-it-means/), [what the pCi/L number means](/air/guides/radon-level-pci-l-what-it-means/) and retest first. ## How was this shortlist built? A radon fan is a swap-in part. EPA's Consumer's Guide to Radon Reduction says fans may last for five years or more and that manufacturer warranties tend not to exceed five years; when the manometer columns level out, the owner needs the same class of fan on the same pipe. This page compares published fan tables, not a bench test: RadonAway's 2023/2024 Radon Professional's Fan Guide (watts, pressure, CFM at stated suction, a replacement chart from Fantech and AMG, now Festa, models), Festa's 2022 catalog and Fantech's Rn2 sheet. Nothing opened printed Rn4 or HP2190 figures, so those cells are blank. In. WC is inches of water column, the suction under the slab that the U-tube on the riser reads directly. ## How do the fans compare on paper? Maker figures at sea level; where a curve stops short of 1.0 in. WC, the nearest printed point is shown. | Fan | Watts | Max pressure (in. WC) | CFM at 1.0 in. WC | Duct | Listing for outdoor or attic use, as printed | Warranty, as printed | | --- | --- | --- | --- | --- | --- | --- | | RadonAway RP140 | 17-21 | 0.78 (0.70 recommended operating) | Not reached; 66 CFM at 0.5 in. | 4 in. | Not printed in the opened guide; product page prints ETL Listed for indoor or outdoor use | 5-year limited (product page) | | RadonAway RP145 | 34-66 | 2.1 (1.7 recommended operating) | 81 | 4 in. | ETL Listed for indoor or outdoor use, UL 507 compliant (product page) | 5-year limited | | RadonAway RP265 | 96-136 | 2.4 (2.3 recommended operating) | 204 | 6 in. | ETL Listed for indoor or outdoor use, UL 507 compliant (product page) | 5-year limited | | RadonAway GP501c (P/N 28468) | 68-146 | 4.1 (3.8 recommended operating) | Not printed; 66 CFM at 2.0 in., 50 at 3.0 in. | 3 in. | Not printed in the opened guide | Not printed in the opened guide | | Festa AMG Maverick | 66 | 2.21 | 116 | 4 in. Fernco | Not printed in the 2022 catalog text | 5-year full replacement | | Festa AMG Eagle | 310 | 4.2 | 177 (130 at 2.0 in., 86 at 3.0 in.) | 3 in. Fernco | Not printed in the 2022 catalog text | 5-year full replacement | | Festa AMG Eagle Extreme | 170 | 5.0 | 248 (179 at 2.0 in., 67 at 4.0 in.) | 3 in. Fernco | Not printed in the 2022 catalog text | 5-year full replacement | | Fantech Rn2 | 59 | 1.9 (0.0-1.8 operating range) | Not printed on the opened sheet | 3 or 4 in. with LDVI couplings | Sheet says the housing can be mounted indoor, outdoor and in wet locations; no UL or ETL mark printed | Not printed on the opened sheet | | Fantech Rn4 | Not readable | Not readable | Not readable | Not readable | Not readable | Not readable | The Fantech HP2190 is absent because Fantech's Rn2 sheet lists it as the older model the Rn2 replaces. RadonAway's figures are from the July 2023 guide; its 2025 RP Pro sheet would not open. ## Which fan for which sub-slab? | Sub-slab condition | RadonAway's guidance (2023/2024 fan guide) | Festa's guidance (2022 catalog) | | --- | --- | --- | | Porous: about 4 in. of clean size 4-6 gravel | RP series, for quiet operation, energy efficiency and high air flow | AMG Maverick, 500-2,200 sq ft on a porous sub-slab such as gravel | | Moderate to tight, or several suction points | GPc series | AMG Eagle, 500-2,000 sq ft on a compact or moist sub-slab such as clay, multiple suction points | | Sand, clay or tight soil needing more suction than an inline fan gives | HS series | AMG Eagle or Eagle Extreme (5.0 in. WC maximum) | | High radon, poor sub-slab communication, large footprint | EC6 | Not stated by class | Your existing U-tube is the shortcut: years at 0.3 in. WC means open fill and an RP140, RP145 or Maverick; near 2 in. WC on a 3 in. pipe means a GP or Eagle class system. ## RadonAway RP145: buy it or skip it? Buy it if the old fan is an RP145, a Fantech HP190, HP2190 or Rn2, or any 4 in. inline fan on a slab that read under about 1.5 in. WC. RadonAway's guide prints 34 to 66 W, 169 CFM free air, 81 at 1.0 in. and 42 at 1.5 in. WC, with a recommended operating ceiling of 1.7 in. WC; the product page prints ETL Listed for indoor or outdoor use, UL 507 compliance and a five-year limited warranty. The listing is titled RP145c, a name the guide and RadonAway's product page (SKU 28461) do not print, so confirm with the seller that it is the RP145 before ordering. The flaw: at 1.7 in. WC the curve is nearly spent, and a tight-soil system needing 2 in. or more is a GP501c job. For a 3 in. riser or a missing manometer, the RP145c kit adds the U-tube, which EPA's Consumer's Guide calls the usual warning device, and two 4 x 3 in. couplings. Skip it if the old fan carried a 6 in. flange: that is the RP265. ## RadonAway RP140: buy it or skip it? Buy it if the system has always read low: RadonAway's guide prints 17 to 21 W, 138 CFM free air and 66 CFM at 0.5 in. WC, 0.70 in. WC recommended operating pressure and a 0.78 maximum, on a 4 in. duct, Energy Star rated. The flaw is the ceiling: the curve ends below 1.0 in. WC, so if the old U-tube ever sat above 0.5 in., the RP140 will stall and the manometer will say so on day one. Skip it on anything but open gravel. ## Festa AMG Maverick: buy it or skip it? Buy it for more flow than the RP145 at the same low suction on a 4 in. gravel system. Festa's 2022 catalog prints 66 W, 260 CFM free air, 116 at 1.0 in. and 40 at 1.5 in. WC, a 2.21 in. WC maximum, a 4 in. Fernco connection and a five-year full replacement warranty, for 500 to 2,200 sq ft on a porous sub-slab such as gravel. The flaw is documentation: the catalog prints no UL or ETL listing and Festa's product page could not be opened. EPA's Consumer's Guide says an outdoor fan must meet local building codes for exterior use, so ask Festa for the listing first. Skip it if the old fan was a GP or Eagle class unit: Festa's own guide maps the RP145, Rn2 and HP2190 to the Maverick and the GP501 class to the Eagle. ## RadonAway RP265: buy it or skip it? Buy it for a 6 in. riser or a large slab with several suction points. RadonAway's guide prints 96 to 136 W, 375 CFM free air, 204 at 1.0 in. and 70 CFM at 2.0 in. WC, a recommended operating ceiling of 2.3 in. WC and a 2.4 maximum; the product page prints ETL Listed for indoor or outdoor use, UL 507 compliance and a five-year limited warranty. The link is the bundle with install kit and bracket, because the bare RP265 was scarce on the day of writing. The flaw is running cost: up to 136 W buys nothing on a small slab. Skip it if the old fan was a 4 in. unit. ## RadonAway GP501: buy it or skip it? Buy it if the old fan is a GP series or a Fantech Rn4 on a 3 in. pipe and the manometer has read 2 in. WC or more. RadonAway's guide prints the current GP501c (P/N 28468) at 68 to 146 W, 3.8 in. WC recommended operating pressure and a 4.1 maximum, with 66 CFM at 2.0 in., 50 at 3.0 and 27 CFM at 3.5 in. WC, on a 3 in. duct, and its chart names the GP501c as one swap for the Fantech Rn4. The flaw is a paperwork gap: the listing is P/N 23005-1, a plain GP501, and the 2023 guide prints rows only for the GP501c and the GP500 (P/N 23003-1). A 2012 catalog's 95 CFM at 1.0 in. WC is not repeated as current. The guide prints no ETL or warranty line for the GP series; confirm both with RadonAway before an outdoor mount. Skip it on a 4 in. gravel system: its curve starts where the RP145's ends. **Before you order a fan** Write down the model on the old fan's label, the pipe diameter at the fan (3, 4 or 6 in.) and the last steady U-tube reading: those decide between an RP140, an RP145 and a GP501c. Then subtract for altitude: RadonAway's guide reduces recommended operating pressure by 4 percent per 1,000 ft, and its example puts the RP145 at 1.3 in. WC and the RP265 at 1.7 in. WC in Denver. If the house has never been tested, or only once, the next purchase is a [radon test or monitor](/air/reviews/best-radon-detector/), not a fan. ## Who should skip a replacement fan? **A house with no system.** EPA's Consumer's Guide says EPA recommends that you have a qualified radon mitigation contractor fix your home, and that without the proper equipment or technical knowledge you could actually increase your radon level or create other potential hazards and additional costs. The Citizen's Guide adds that a reader considering a do-it-yourself fix should first contact the state radon office; the Consumer's Guide cites ASTM E2121 as the installation standard. **A house tested once.** EPA's Citizen's Guide asks for a follow-up test before fixing; the [pCi/L guide](/air/guides/radon-level-pci-l-what-it-means/) covers the 4 pCi/L action level and the second test. **A radon result in the well water.** That is a different measurement and treatment class, covered under [uranium and radon in well water](/water/guides/uranium-radon-in-well-water/). **Watching the number from upstairs.** A continuous monitor such as the Airthings units in the [air quality monitor review](/air/reviews/best-air-quality-monitor-pm25-co2/) shows the long-term average; EPA says to retest at least every two years. ## What goes wrong? **Mounting the fan in living space.** EPA's Consumer's Guide says the exhaust fan must not be located in or below a livable area; attics, garages and the exterior are the common locations it names. **Switching it off to save power.** EPA's wording is that the fan should never be turned off and must run continuously; if the wattage bothers you, the RP140 draws 17 to 21 W. **Changing the duct size at the fan.** RadonAway's guide puts the airflow cost of each duct size reduction at about 20 percent. **Losing the warning device.** EPA's Consumer's Guide says a warning device must be installed where it can be seen or heard easily; a fan swapped without a manometer leaves the next failure invisible. If the suction point is a sealed sump pit, the pump under the lid still needs its own checks, covered in the [sump pump review](/plumbing/reviews/best-sump-pump-and-battery-backup/). ## The picks - **RadonAway RP145 (4 in.)**: Replacing the fan on a typical 4 in. system over gravel or mixed fill (RadonAway 2023/2024 fan guide: 34-66 W, recommended max operating pressure 1.7 in. WC, 169 CFM at 0 in., 124 at 0.5, 81 at 1.0, 42 at 1.5 in. WC; 4 in. duct; product page prints ETL Listed for indoor or outdoor use, UL 507 compliant, five-year limited warranty) Amazon: https://www.amazon.com/dp/B00294RBFM/?tag=ownerspec-20 - **RadonAway RP145c kit with U-tube manometer and two 4 x 3 in. couplings**: Same fan for a 3 in. pipe system, or a system whose manometer is missing or dry (Listed as RP145c; the opened maker documents print no RP145c, so confirm it is the fan above. Bundled with a U-tube manometer (EPA's Consumer's Guide calls the manometer the usual warning device) and two 4 in. to 3 in. PVC couplings) Amazon: https://www.amazon.com/dp/B0GMS6S3SY/?tag=ownerspec-20 - **RadonAway RP140 (4 in.)**: Lowest running cost on a porous sub-slab where the old fan read under 0.5 in. WC (RadonAway 2023/2024 fan guide: 17-21 W, recommended max operating pressure 0.70 in. WC, max 0.78 in. WC, 138 CFM at 0 in., 66 CFM at 0.5 in. WC; 4 in. duct; Energy Star rated per the guide) Amazon: https://www.amazon.com/dp/B00294S5XO/?tag=ownerspec-20 - **Festa AMG Maverick (4 in.)**: Alternative to the RP145 on gravel, with more flow at low suction (Festa 2022 catalog: 66 W, 260 CFM at 0 in., 201 at 0.5, 116 at 1.0, 40 at 1.5 in. WC; 2.21 in. WC max pressure; 4 in. Fernco; recommended for 500-2,200 sq ft on a porous sub-slab such as gravel; 5-year full replacement warranty) Amazon: https://www.amazon.com/dp/B0B5W2PXWV/?tag=ownerspec-20 - **RadonAway RP265 with install kit and mounting bracket (6 in.)**: Large footprint or multiple suction points on a 6 in. riser (RadonAway 2023/2024 fan guide: 96-136 W, recommended max operating pressure 2.3 in. WC, max 2.4 in. WC, 375 CFM at 0 in., 282 at 0.5, 204 at 1.0, 140 at 1.5, 70 at 2.0 in. WC; 6 in. duct; product page prints ETL Listed for indoor or outdoor use and a five-year limited warranty) Amazon: https://www.amazon.com/dp/B00FIV44AS/?tag=ownerspec-20 - **RadonAway GP501 (P/N 23005-1, 3 in.)**: Clay or tight soil where the old fan ran above 2 in. WC on a 3 in. pipe (RadonAway 2023/2024 fan guide prints the GP501c (P/N 28468): 68-146 W, recommended max operating pressure 3.8 in. WC, max 4.1 in. WC, 66 CFM at 2.0 in., 50 at 3.0 in. WC; 3 in. duct. The guide lists no row for P/N 23005-1, so treat these as the series figures) Amazon: https://www.amazon.com/dp/B0028PICB4/?tag=ownerspec-20 ## Frequently asked questions ### Can I replace a radon fan myself, or do I need a contractor? EPA's Consumer's Guide to Radon Reduction says EPA recommends that you have a qualified radon mitigation contractor fix your home, and that without the proper equipment or technical knowledge you could increase your radon level or create other hazards. For a like-for-like fan swap, the Citizen's Guide says to contact your state radon office first for guidance; some states license mitigation work. ### Which RadonAway fan replaces a Fantech HP2190 or Rn2? RadonAway's 2023/2024 fan guide carries a replacement chart: the Fantech HP190, HP2190, Rn2 and Rn2EC are replaced by the RP145 or the LV175, and the Rn4 by the GX4, GX5A, GP501c or EC6. Festa's catalog maps the other way: the RP145, Rn2 and HP2190 to its Maverick or Patriot, and the GP501 class to its Eagle. Match the pipe diameter as well as the model. ### Is a higher CFM radon fan better? No. A fan curve trades flow for suction, and the sub-slab decides which you need. RadonAway's guide places its RP series on porous sub-slabs with about 4 in. of clean gravel, its GPc fans on moderate to tight conditions and its HS fans on sand, clay or tight soil. A 375 CFM RP265 on tight clay moves little air and a GP501c on open gravel wastes watts and noise. ### How long does a radon fan last and how do I know it has failed? EPA's Consumer's Guide says fans may last for five years or more, that manufacturer warranties tend not to exceed five years, and that the fan must never be turned off. The usual warning device is a U-tube manometer: with the fan running the two columns sit at different heights, and when they level out the fan has stopped. EPA says to check it regularly and retest every two years. ### Where can the radon fan be mounted? EPA's Consumer's Guide says the exhaust fan must not be located in or below a livable area, and that common locations are unconditioned home and garage spaces, including attics and the exterior of the home. An outdoor fan must meet local building codes for exterior use. RadonAway's RP145 and RP265 pages print ETL Listed for indoor or outdoor use; Festa and Fantech print no listing in the documents read. ## Sources - [RadonAway, 2023/2024 Radon Professional's Fan Guide](https://www.radonaway.com/pdfs/radon-newsletters/pdfs/RA_2023_24_Fan_Guide.pdf) (manufacturer or vendor document) - [RadonAway, RP145 Pro Series product page](https://www.radonaway.com/products/radon-fans/pro-series/rp-series/rp145-pro) (manufacturer or vendor document) - [RadonAway, RP140 Pro Series product page](https://www.radonaway.com/products/radon-fans/pro-series/rp-series/rp140-pro) (manufacturer or vendor document) - [RadonAway, RP265 Pro Series product page](https://www.radonaway.com/products/radon-fans/pro-series/rp-series/rp265-pro) (manufacturer or vendor document) - [Festa Radon Technologies, 2022 product catalog (AMG fans)](https://www.hvacquick.com/catalog_files/Festa_Line_Catalog.pdf) (manufacturer or vendor document) - [Fantech, Rn2 spec sheet (Systemair Art. E1800, July 2018)](https://www.hvacquick.com/catalog_files/Fantech_RN2_Spec_Sheet.pdf) (manufacturer or vendor document) - [Fantech, product catalog 89052 (Rn1 to Rn4)](https://www.gtsanders.com/userfiles/ad/documents/Fantech_89052_Catalog.pdf) (manufacturer or vendor document) - [EPA, Consumer's Guide to Radon Reduction (EPA 402/K-10/005)](https://www.epa.gov/sites/default/files/2016-12/documents/2016_consumers_guide_to_radon_reduction.pdf) (government or regulatory source) - [EPA, A Citizen's Guide to Radon (EPA 402/K-12/002)](https://www.epa.gov/sites/default/files/2016-12/documents/2016_a_citizens_guide_to_radon.pdf) (government or regulatory source) --- Citation: OwnerSpec, "Best radon mitigation fan: RadonAway, Festa and Fantech fan curves compared by watts, suction and CFM, with the maker's own sub-slab guidance deciding which one replaces yours", https://ownerspec.com/air/reviews/best-radon-mitigation-fan/, facts verified 11 October 2026. Canonical citation target: the URL above (the public HTML page), not this Markdown representation. Reuse: quoting with attribution and a link is permitted. See https://ownerspec.com/legal/terms/.