Security Fog for Banks
Bank branches are the most security-mature retail vertical in the U.S. The remaining attack vector is the after-hours ATM ram-raid, which sits outside the strength of traditional branch security. A security fog system covering the ATM vestibule and the back-office cash room adds the active-intervention layer the existing stack lacks.
Bank threat: vault & ATM
Modern bank branches are already heavily defended during business hours by guards, time-delay vaults, dye packs, monitored alarms and elaborate camera coverage. The remaining gaps are after-hours:
- ATM ram-raid. Stolen vehicle through the ATM vestibule or through-the-wall ATM. 60-120 seconds from impact to cash. Up to $200,000 per machine.
- After-hours back-office breach. Forced entry to night-deposit safe room or cash counting area. 5-15 minute dwell with specialty tools.
- Lobby ATM tampering. Card-skimmer installation, ATM-shimmer attacks, brute-force cash retention removal — not stopped by fog but worth noting context.
ATM ram-raids
The ram-raid problem is unique because the crew is on a vehicle clock, not a foot clock. They’re committed and they’re fast. Security fog handles the post-impact phase:
- Vehicle impact triggers shock and glass-break sensors on the ATM vestibule (typically 1-2 seconds)
- Alarm panel verifies and closes fog trigger circuit
- Fog fills the vestibule and the lobby within 10 seconds
- Crew is inside but can’t see the ATM cassette, the safe-bolt cuts, or the exit
- Documented retreat in 30-90 seconds — before any cash cassette is fully extracted
Through-the-wall ATMs are addressed with a small dedicated fog unit covering the ATM’s back-of-machine service alcove, triggered on tamper.
Layering fog with bank systems
Bank fog deployments emphasize layering, not replacement. Active deterrence sits alongside the existing stack:
- Monitored alarm + central station notification — unchanged
- Time-delay safe and cash vault — unchanged
- Camera coverage and analytics — unchanged (fog visibility actually triggers fog-detection analytics that confirm the event)
- Dye-pack and GPS bait money — complementary
- Security fog as new active layer: ATM vestibule + back-office cash room + branch lobby
Branch placement
Standard zoned deployment at a 200-500 m² branch:
- Zone 1 — ATM vestibule: 2-can fog unit, fires on vestibule shock + glass-break
- Zone 2 — back-office cash room: 2-can unit, fires on cash-room entry + PIR
- Zone 3 — main lobby (optional): 4-can unit for full-lobby coverage on after-hours forced front-entry. Generally lower priority because lobbies hold less value.
Each zone has independent trigger logic — an event in one zone does not fire fog in another zone.
See also: cash rooms · fog vs access control · integrate with existing system · buyer’s guide.
Frequently asked questions
Will fog damage ATM electronics or cash inside the cassette?
No. ATMs are sealed against environmental exposure as standard design. Food-grade glycol fog is non-conductive and does not penetrate sealed ATM compartments. Cash inside the cassette is unaffected.
Does fog interfere with bank alarm central-station signaling?
No. The fog system fires after the alarm event is already in progress on the central station. Fog discharge is a follow-on response, not part of the signaling chain.
How does the fire-alarm coordination work in a bank branch?
Same as any other commercial install: the fog firing closes a relay that puts the smoke-detection zone covering the protected area on a 60-90 minute timed bypass. The branch's fire alarm panel handles this routinely per NFPA 72.
Will fog affect the bank vault time-delay lock?
No. Vault time-delay locks are mechanical/electronic systems sealed against environmental exposure. They operate independently of fog deployment.
Do bank insurers and the FDIC have any objection to fog systems?
No. The FDIC has no specific position on fog systems. Bank-line property insurers and surety bond underwriters increasingly recognize fog installations as positive risk-mitigation evidence at policy renewal.
