AEDs should be placed so that a rescuer can grab one and return to a person in cardiac arrest within 3 to 5 minutes. That’s the core guideline from the American Heart Association, and every other placement decision flows from it. In practical terms, this means no more than about 1½ to 2½ minutes of walking in each direction between any point in a building and the nearest device.
Getting this right matters enormously. Every one-minute delay in responding to cardiac arrest is associated with roughly a 9% decrease in the chance of good neurological recovery and a 7% drop in survival. An AED tucked in a back office or locked behind a security desk can cost someone their life.
The 3-to-5-Minute Rule
The AHA’s implementation guide for on-site AED programs frames placement around a simple round-trip walk test. From any location in your building or campus, someone should be able to walk to the nearest AED, retrieve it, and walk back within 3 to 5 minutes total. That breaks down to roughly 1½ to 2½ minutes each way.
To figure out how many AEDs you need, walk the longest route from the farthest corner of your space to the proposed AED location and time it. If it takes more than 2½ minutes at a brisk walk, you need another unit. Large open-plan offices, warehouses, and campuses with multiple buildings almost always need more than one. Some organizations use a square-footage benchmark as a starting point. A Virginia state report found that facilities commonly placed one AED per 21,000 to 25,000 square feet, though the right number depends on building layout, not floor area alone.
High-Priority Locations
Certain areas carry higher cardiac arrest risk and should be prioritized when deciding exactly where to mount an AED:
- Fitness centers and gyms: Intense physical exertion is a well-known trigger for sudden cardiac arrest, making these among the highest-priority spots.
- Cafeterias and common areas: Large gatherings of people increase the statistical likelihood of a cardiac event happening nearby.
- Main hallways and lobbies: High-traffic corridors are easy to find under pressure and accessible from multiple directions.
- Near elevators and stairwells: These serve as natural central access points, especially in multi-story buildings.
- Outdoor athletic fields and pools: Any area where people exercise vigorously warrants nearby AED access.
The CDC identifies airports, schools, fitness facilities, casinos, churches, and workplaces as public locations where cardiac arrest is most likely to occur and where AED placement has proven effective.
Multi-Story and High-Rise Buildings
Vertical distance is the hidden problem in AED placement. Running down four flights of stairs to a lobby AED and back up again can easily blow past the 3-to-5-minute window. Research on optimal defibrillator placement in high-rise buildings found that in tall buildings or those where cardiac arrest risk is spread evenly across floors, placing an AED inside or near the elevator results in shorter response distances than keeping one only in the lobby.
Lobby placement works better in buildings where most foot traffic and risk concentrate on the ground level, underground areas, or nearby street-level entrances. For buildings taller than a few stories with significant occupancy on upper floors, the general principle is at least one AED per floor, or per every two to three floors at minimum, positioned near elevators or central stairwells. Schools commonly use one AED per floor as their standard.
Visibility and Signage
An AED that nobody can find in a panic is nearly as useless as one that isn’t there. Mount devices in plain sight along main corridors, not inside closets or behind reception desks. Standard green-and-white AED signs should be posted at eye level both on the cabinet and at nearby intersections or hallway junctions so someone unfamiliar with the building can spot one quickly.
Wall-mounted cabinets at roughly chest height are the most common setup. Many cabinets include audible alarms that sound when opened, which serves the dual purpose of alerting others that an emergency is underway and deterring theft.
Locked Cabinets Slow Response
The International Liaison Committee on Resuscitation advises against using locked AED cabinets. Simulation studies consistently show that locked cabinets significantly slow AED retrieval time, and mapping studies confirm that locking AEDs inside buildings reduces their real-world accessibility. If a lock is used for theft prevention, the unlocking instructions need to be immediately visible and require no special tools, codes that must be looked up, or keys held by a single person. The goal is zero delay: someone running to the cabinet in a crisis should be able to open it without stopping to problem-solve.
Outdoor and Extreme-Temperature Placement
AEDs placed outdoors, in vehicles, or in unconditioned spaces face temperature challenges. Most manufacturers rate their devices for operation between 32°F and 122°F (0°C to 50°C), with storage limits slightly wider at 14°F to 122°F (-10°C to 50°C). Below those thresholds, the conductive gel on electrode pads can thicken, crack, or freeze solid, making them useless.
If you need an AED at an outdoor sports field, pool area, or entrance that isn’t climate-controlled, heated AED cabinets are available and designed for exactly this purpose. They maintain the internal temperature within the device’s operating range year-round. In hot climates, shaded or ventilated cabinets prevent the opposite problem of heat degradation to batteries and pads.
State Laws and Legal Requirements
AED placement isn’t just a best practice. Many states make it a legal requirement for certain facilities. As of recent CDC analysis, 37 states required or authorized specific types of locations to have AEDs on-site. The most commonly mandated locations are schools (25 states), health and fitness facilities (15 states), and state-owned or state-occupied buildings (10 states). A smaller number of states mandate AEDs in gambling venues and public golf courses.
Requirements vary significantly by state, so checking your state’s specific statute is worth the effort. Beyond the legal mandate, many states also offer Good Samaritan protections for bystanders who use an AED in an emergency, which is one more reason to make the devices visible and accessible to everyone, not just trained staff.
Practical Placement Checklist
- Walk-test every location: Time the round trip from the farthest point in your space. If it exceeds 5 minutes, add another AED.
- Prioritize high-exertion areas: Gyms, athletic fields, and pools should have the closest access.
- Choose high-traffic mounting spots: Main hallways, lobbies, near elevators, and break rooms are easier to find under stress than back offices.
- One per floor in multi-story buildings: Vertical travel time adds up fast.
- Keep cabinets unlocked: Or use alarm-only cabinets that open freely.
- Use climate-controlled cabinets outdoors: Protect pads and batteries from freezing or extreme heat.
- Post clear signage: Standard AED markers at the cabinet and at hallway decision points.
- Register your AED: Many communities maintain AED registries that 911 dispatchers can reference to direct callers to the nearest device.