Where to Place a Radon Detector

On this page (8 sections)

1. Which room is best for a radon detector?
2. How high should you install a radon detector?
3. How far should a detector be from windows and drafts?
4. Should I place a radon detector in the basement?
5. Where should I avoid placing a radon detector?
6. Which radon test kits fit common placement needs?
7. How can I tell whether the detector was placed correctly?
8. Where to place a radon detector for a reliable test

Place a radon detector on the lowest level of your home that people use regularly, in a room with normal airflow and no drafts. Set it at the height and distance from windows, doors, vents, and fans required by its instructions.

For many homes, that means a finished basement living area. If you don't have a basement, use a regularly occupied room on the first floor.

If you're unsure whether one is installed, see how to check for a home radon detector.

A radon detector may be a continuous monitor or a test kit, so check its directions before choosing a spot. [What Is a Radon Detector?

A Simple Guide](/what-is-a-radon-detector/) explains the difference between common detector types.

Which room is best for a radon detector?

Choose a room on the lowest level where people spend time, such as a family room, bedroom, or finished basement living area. The goal is to measure a space that reflects everyday exposure, rather than an unused area with different conditions.

If your basement is unfinished and used only for storage, follow the test instructions for the appropriate lowest livable level. Don't put a detector in a crawl space, closet, laundry room, kitchen, bathroom, or mechanical room unless the device directions specifically call for it.

Avoid rooms where temperature, moisture, or airflow can be unusual. A kitchen range hood, bathroom fan, furnace vent, or frequently opened exterior door can change local conditions.

How high should you install a radon detector?

Use the height range in the detector's instructions. Placement guidance varies, so the device's directions take priority over a general rule.

For a detector that can rest on a shelf or table, choose a firm, level surface that won't be covered by books, curtains, or household items. For a mountable unit, use the approved attachment method and make sure it cannot fall or be moved accidentally.

Keep it away from the floor and ceiling if the instructions specify a range. Don't place it on a radiator, near a heater, or in direct sunlight.

How should you mount a radon detector?

Mount a detector only if its instructions allow mounting, and use a stable, approved surface. A shelf, table, or other firm spot may work for a test kit that is designed to sit flat.

Don't tape over vents or openings on a monitor. Don't hang a kit by its packaging or leave it somewhere children or pets could disturb it during the test.

How far should a detector be from windows and drafts?

Keep the detector away from windows, exterior doors, fans, and vents by the distance stated in its instructions. These spots can have more air movement than the rest of the room.

Close windows and exterior doors as directed during a short-term test. Don't place the detector directly beside a supply vent, return vent, ceiling fan, or air purifier.

Don't put a detector behind furniture or inside a cabinet. It needs to sit in the room's air, with enough clearance to remain undisturbed.

Should I place a radon detector in the basement?

A basement is a good location when people use it regularly. Choose a finished room or another normal living area, then follow the detector's placement and test instructions.

A basement storage space or utility area may not reflect the air in rooms where people spend time. If the basement isn't used as living space, check the instructions to see whether the detector should go on the first floor instead.

Some short-term kits require closed-building conditions for a set period. Follow the kit directions for doors, windows, fans, and the length of the test.

Does a radon detector need to be in a bedroom?

A bedroom can be a suitable location if it's on the lowest regularly occupied level and meets the device's placement rules. Keep the detector away from the window, curtains, and areas where it could be covered or knocked over.

If the bedroom is upstairs while a lower level is used regularly, follow the instructions for the lowest livable level. For a general overview, see [Do Home Radon Detectors Work?

A Plain Guide](/do-home-radon-detectors-work/).

Where should I avoid placing a radon detector?

Avoid spots with drafts, heat, moisture, or frequent disturbance. These conditions can make it harder to follow the test directions or interpret the result.

Keep a detector away from:

• Windows and exterior doors
• Heating and cooling vents, fans, and air purifiers
• Kitchens, bathrooms, and laundry areas
• Direct sunlight, radiators, and other heat sources
• Cabinets, closets, and spaces behind furniture
• Areas where children, pets, or stored items may move it

If the instructions give a specific clearance, use that measurement. Don't move the detector once a test has started unless the directions say to do so.

Which radon test kits fit common placement needs?

Choose a test kit based on its instructions, test period, and the room where you plan to place it. These options are charcoal test kits, so set them up and leave them undisturbed as directed.

The First Alert kit includes test materials and lab fees, with New Jersey state fees excluded. First Alert says results are emailed within 72 hours of lab receipt.

The Leaping Lynx kit calls for placement on the lowest livable level and a 48-hour test. Its kit includes an activated charcoal detector, instructions, registration materials, and a return mailer; return postage is required.

The AccuStar kit is intended for a 48–96 hour short-term test. Its instructions call for the detector to remain undisturbed under closed-building conditions.

How can I tell whether the detector was placed correctly?

A detector is placed correctly when it follows the device's rules for room, height, clearance, and test conditions. Before starting, confirm that the location is on the right level, away from drafts, and unlikely to be disturbed.

Keep the setup instructions with the detector while it runs. Once the test is complete, use how to read a radon detector to understand what its result means and what steps may follow.

A smoke alarm does not measure radon. If you're checking how the devices differ, read Can a Smoke Detector Detect Radon?.

Where to place a radon detector for a reliable test

For a useful home screening, choose the lowest regularly occupied level, use a normal living area, and follow the detector's own placement instructions. Keep it at the specified height, away from windows and drafts, and undisturbed for the full test.

Pick a finished basement room if people use it often, or a first-floor room if there is no regularly used basement. Before opening a kit, check its rules for closed-house conditions, test duration, and placement so the detector stays in the right spot.

Frequently asked questions

Where should I place a radon detector?

Place it on the lowest level of your home that people use regularly, such as a finished basement or first floor if there is no basement. Follow the device instructions for height and distance from windows, doors, exterior walls, and drafts.

Avoid kitchens, bathrooms, and places with unusual heat or humidity.

How high should a radon detector be?

Use the height range in the detector's instructions, since placement guidance can vary by device and test method. Choose a stable surface or approved mounting point, and keep the detector away from the floor, ceiling, and spots where it could be bumped or covered.

Can I put a radon detector near a window?

Avoid placing a detector near a window, exterior door, or other source of drafts unless its instructions say otherwise. Air movement can affect the test conditions.

Keep the device in a room used regularly and follow the specified clearance from openings, vents, and fans.

Can I put a radon detector in a basement?

Yes, if the basement is the lowest level people use regularly. Put the detector in a normal living area, not a crawl space, utility room, bathroom, or storage area that people rarely enter.

Follow the test kit's directions for closed-house conditions, placement height, and test duration.