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Kidde

Kidde Radon Detector (RAB)

Battery digital radon detector with an alarm

  • Monitor
  • Battery
  • Screen
  • First reading in 12 hours
C-NRPP 2024/25 evaluation: Not includedSee the evidence

Best for, and skip if

Best for you if

  • You want an audible alarm when the daily average passes 4 pCi/L.
  • You want a battery detector with a screen and no app, phone or Wi-Fi to set up.

Skip it if

  • You want a device that was itself graded in C-NRPP's 2024/25 evaluation.
  • You want a reading within minutes; the first figure takes 12 hours and a reliable one up to 48 hours at lower levels.
See how it compares: Best radon monitors, every model comparedWho it fits
  • Kidde Radon Detector (RAB)
  • Kidde Radon Detector (RAB), photo 2 of 5
  • Kidde Radon Detector (RAB), photo 3 of 5
  • Kidde Radon Detector (RAB), photo 4 of 5
  • Kidde Radon Detector (RAB), photo 5 of 5

Photos: Kidde

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  • PowerBattery
  • ReadingsScreen
  • First reading12 hours
  • C-NRPP 2024/25Not included
  • Every figure checked against the specifications Kidde publishes
  • Independent test results shown the same way for every product, unranked
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About this item

As Kidde states it

  • How it measures: Semiconductor radon sensor, passive diffusion through side vents
  • First reading: Within 12 hours
  • Reading updates: Updates every 60 minutes; half-day, 1-day, 3-day and 7-day averages on the screen
  • Display and app: Built-in display, no app
  • Power: Battery: 3 AAA batteries, included
  • Units: pCi/L by default; Bq/m³ selectable

The Kidde RAB is a battery-powered radon detector from Kidde's DETECT series: a semiconductor radon sensor, an LCD screen with averages up to 7 days, and a buzzer that sounds when the average passes 4 pCi/L. It runs on three AAA batteries, has no app, and was not included in C-NRPP's 2024/25 evaluation.

What you get

The detector comes with three AAA batteries included, and Kidde's data sheet lists a 1-year limited warranty. It measures 4.2 by 2.1 by 0.9 inches and weighs 0.27 lb. Kidde's data sheet lists UPC 047871343195 among its ordering codes, which helps match the right product on a shelf.

In the box and running costs

How it works

What it measures and how

The sensor, the sampling and the readings, then who has checked it

How it works

In our words, from the maker's documents

Kidde's user guide describes the RAB as a portable radon concentration monitor that tracks the alpha radiation formed as radon decays, using a semiconductor radon sensor. Air reaches the sensor through vents on the sides of the case, which Kidde says let radon diffuse in quickly. There is no pump and no fan.

It takes time to give a number. The screen shows the first reading after 12 hours, with a countdown to that first update, and the reading then updates every 60 minutes. Kidde gives the time to a reliable reading as 12 hours above 6.4 pCi/L, 24 hours between 4.2 and 6.4 pCi/L, and 48 hours below 4.2 pCi/L, so at the levels most homes see, the first two days are a warm-up.

The screen is built around averages. After 12 hours, a short press of the Reset button steps through the averages for the past half day, 1 day, 3 days and 7 days; once it has run for a week, the display cycles through the 1-day, 3-day and 7-day averages every 10 seconds. Kidde also lists an accumulated average among the values it records.

Kidde lists a measurement range of 0.09 to 1,000 pCi/L, and the screen shows pCi/L by default, with a Unit button to switch to Bq/m³. Its data sheet prints the EPA's three bands beside the readings: below 2.0 pCi/L, continue monitoring; 2.0 to 3.9, consider steps to reduce radon; 4.0 or higher, take action to mitigate.

Kidde's guide adds a caution worth knowing for any detector of this kind: at low radon levels the random nature of radon decay means counts vary and two units can differ slightly, so it recommends using an average over 7 days or more. After a high reading, it says residual radon decay products inside the device can take from 24 hours to 3.8 days to decay, so allow 24 to 48 hours after moving it before trusting the number.

What the manufacturer says

Kidde's own statements, attributed

  • Kidde saysKidde states the RAB provides an initial reading in about 12 hours and continuously tracks radon levels.
  • Kidde saysKidde states battery life of at least one year with the screen off, under normal conditions, on three AAA batteries.
  • Kidde saysKidde states the alarm sounds for 20 seconds every hour once the past day's average radon concentration exceeds 4 pCi/L.
  • Kidde saysKidde describes the RAB as detecting the presence of radon, and says it is not intended for the prevention or mitigation of radon.

These are Kidde's own statements, attributed to it. They are not our findings, and we have not tested this product ourselves.

Independent evidence

C-NRPP 2024/25, recalls and studies

C-NRPP 2024/25
Not included in C-NRPP's 2024/25 evaluation

The Canadian National Radon Proficiency Program's 2024/25 comparison of consumer monitors did not include Kidde Radon Detector (RAB). That is a fact about which devices took part, not a finding about this one: no result from that program exists for it either way.

Recalls
No Health Canada recall or advisory names this device.
Peer-reviewed studies
We found no peer-reviewed comparison that names this model.
Notes
  • A newer battery-powered monitor on Kidde's US site.

C-NRPP is the Canadian National Radon Proficiency Program. Its 2024/25 results were published in May 2025.

Kidde Radon Detector (RAB)

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Specifications

Specifications

Every figure as the maker states it

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The maker's figures

Type
Continuous monitor, battery, LCD, semiconductor sensor, alarm
How it measures
Semiconductor radon sensor, passive diffusion through side vents
First reading
Within 12 hours
Reading updates
Updates every 60 minutes; half-day, 1-day, 3-day and 7-day averages on the screen
Display and app
Built-in display, no app
Power
Battery: 3 AAA batteries, included
Units
pCi/L by default; Bq/m³ selectable

What is in the box

The detector comes with three AAA batteries included, and Kidde's data sheet lists a 1-year limited warranty. It measures 4.2 by 2.1 by 0.9 inches and weighs 0.27 lb. Kidde's data sheet lists UPC 047871343195 among its ordering codes, which helps match the right product on a shelf.

What it costs to run

There is no lab fee, app or subscription. The running cost is batteries: three AAA cells, which Kidde says last at least a year in normal conditions. Kidde names Energizer E92 as the replacement, warns against lithium cells and against mixing old and new or different types, and suggests replacing them at least once a year.

Fit and setup

Who it fits, and how to use it

The fit, then setup and placement as the guidance asks

Who it fits

Good fit if, and look elsewhere if

Good fit if

  • You want an audible alarm when the daily average passes 4 pCi/L.
  • You want a battery detector with a screen and no app, phone or Wi-Fi to set up.
  • You want daily, 3-day and 7-day averages shown on the device itself.
  • You prefer a radon detector from a maker whose smoke and carbon monoxide alarms you already use.

Look elsewhere if

  • You want a device that was itself graded in C-NRPP's 2024/25 evaluation.
  • You want a reading within minutes; the first figure takes 12 hours and a reliable one up to 48 hours at lower levels.
  • You want a record beyond 7-day averages, or graphs on your phone.
  • You need a result for a home sale; check what your state accepts before relying on any consumer detector.

Setup and placement

4 steps

  1. To start, press and hold the Power button for 3 seconds until the buzzer beeps once and the screen lights. The alarm is on by default; a short press of Mute turns it off or on. To start a new measurement, for example after moving the detector, hold Reset for 3 seconds, which clears the data and begins a new 12-hour cycle.
  2. Kidde says to place it in the lowest livable level of the home for the most accurate readings, and that it measures radon only at the sensor, so radon may be present in other areas. It is meant for indoor residential use, is not waterproof, and should not be dropped or shaken. Kidde gives a working range of 14 to 113°F with humidity below 90%, non-condensing, and says readings outside that range are not accurate.
  3. The EPA's general guidance for any radon test adds the details: the lowest lived-in level, a room used regularly but not the kitchen or bathroom, at least 20 inches above the floor, and away from drafts, high heat, high humidity and exterior walls. C-NRPP's advice for consumer monitors is to run one for at least 3 months, preferably in the heating season, and decide on the long-term average.
  4. Kidde's guide also suggests ventilating for at least 10 minutes when the reading is above 4 pCi/L. Opening windows changes what a detector reads at that moment; it does not fix a radon problem. The EPA's advice is to fix a home with a radon level of 4 pCi/L or more, and Kidde's own page says a certified professional can install a mitigation system.

How C-NRPP says to use any consumer monitor

  • Leave it in place for at least three months, ideally through the heating season, when indoor radon tends to be highest.
  • Put it in a room someone uses for at least four hours a day.
  • Decide about fixing your home from the long-term average, not a single day or week.
  • If you can only run a monitor for less than 91 days, follow up with a long-term test.

For where any radon test or monitor should sit in a home, see where to place a radon test.

Compare

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Questions

Questions people ask

6 questions about the Kidde Radon Detector (RAB), answered

Asked about the Radon Detector (RAB)

How long does the Kidde radon detector take to show a reading?

Kidde says the first reading appears after 12 hours, shown as dashes until then. A reliable reading takes 12 hours above 6.4 pCi/L, 24 hours between 4.2 and 6.4 pCi/L, and 48 hours below 4.2 pCi/L.

Why does my Kidde radon detector beep?

Kidde says it sounds for 20 seconds every hour when the average radon concentration over the past day has exceeded 4 pCi/L, with an icon in the upper left of the screen. A short press of Mute turns the alarm off or on.

Does the Kidde RAB detect carbon monoxide or smoke?

No. Kidde's guide says radon detectors are designed to detect radon gas only, not smoke, fire, carbon monoxide or any other gas. Keep your smoke and carbon monoxide alarms as they are.

Is the Kidde radon detector C-NRPP approved?

It was not included in C-NRPP's 2024/25 consumer monitor evaluation, so there is no C-NRPP result for it either way.

What batteries does it use?

Three AAA batteries, included. Kidde names Energizer E92 for replacements, says not to use lithium cells or mix old and new batteries, and rates battery life at a year or more with the screen off.

Can I switch it to Bq/m³?

Yes. It shows pCi/L by default, and a short press of the Unit button switches between pCi/L and Bq/m³.

What to do next

Updated October 4, 2026