How Security Fog Is Installed

A security fog install is a half-day job for a licensed alarm technician: mount the unit, wire two terminals to your existing alarm panel, coordinate one timed shunt with the fire panel, run a live test, and document for your insurance broker. No structural work, no new permits, no rewiring.

Install overview & timeline

The standard install runs 3-5 hours on a single-zone retail or office space. The phases:

1. Site survey (1 hour, sometimes done in advance): walkthrough to confirm mounting location, alarm panel access, fire-panel coordination plan.
2. Mounting (45 minutes): wall or ceiling mount above the entry path, nozzles aimed across the protected zone.
3. Wiring to alarm panel (45 minutes): two-wire connection from the panel’s programmable output to the fog unit’s IN+ / IN− terminals.
4. Fire panel coordination (30 minutes): program the timed shunt; verify live with your fire-alarm tech.
5. Commissioning & test (30 minutes): live discharge test, walkthrough with the operator, sign-off paperwork.
6. Documentation (15 minutes): one-pager for your fire marshal file and insurance broker.

Optimal placement

The fog unit’s job is to fill the space between the intruder and what they came to steal. Standard placement principles:

• Above the entry door, nozzles aimed back across the customer-side floor — fog reaches the cases before the crew does.
• 2.0-2.5 m off the floor — high enough that natural airflow spreads the fog evenly, low enough that the discharge cone covers customer height.
• Pointed at the entry path, never at the back wall. The intruder should be engulfed in fog, not silhouetted against it.
• Avoid HVAC vents within 1 m of the nozzles — airflow can pull the fog away before density peaks.
• Multi-room installs: one unit per protected zone, each with its own trigger logic.

Wiring into your alarm panel

The fog unit accepts a standard dry-contact trigger on the IN+ / IN− terminals. Any commercial alarm panel made in the last 20 years has at least one programmable output that closes on alarm; that’s the trigger path. Standard wiring:

• Trigger circuit: two-conductor low-voltage wire from the alarm panel output to the fog unit’s IN+ / IN− (typical run: under 50 m at 18 AWG).
• Power: 12-volt DC at the unit, drawn from a dedicated UPS-backed circuit to keep the unit live during outage attempts.
• Tamper loop: a separate two-conductor loop reports housing-cover removal back to the alarm panel as a sensor zone.
• Optional remote: RF-encrypted handheld pair for daytime arming and manual fire.

Two-sensor verification is the discipline: program the panel so the fog only fires when two independent sensors (e.g., glass-break + interior PIR) trip within a short window. This prevents false discharges from a single nuisance sensor.

Professional install vs supervised self-install

Three reasons most insurance carriers require a licensed alarm tech to do the install:

1. Certificate of installation. Carriers ask for a one-pager signed by a licensed installer to qualify your premium discount.
2. Fire panel coordination. The smoke-zone shunt program must be entered by someone licensed to modify fire-alarm panel firmware.
3. Two-sensor verification logic. Mis-programmed trigger logic causes false discharges — the most expensive and most common installer mistake.

For sites where the operator has alarm-installer credentials in-house, supervised self-install is acceptable; the carrier paperwork still requires the licensed sign-off.

Site survey checklist

Before the install crew arrives, confirm these:

• ☐ Room volume calculated & correct fog mode selected (2/4/6-can)
• ☐ Alarm panel make/model known and accessible
• ☐ Fire alarm panel make/model known (for shunt coordination)
• ☐ Mounting wall identified & cleared
• ☐ UPS or dedicated circuit available for fog unit power
• ☐ Fire marshal notification drafted (one-pager)
• ☐ Deterrent signage ready to mount on the front door
• ☐ Two spare sealed canisters on site
• ☐ Insurance broker informed of pending install date

For specific brand-level wiring (Ajax, Bosch, Honeywell, DSC), see our alarm integration guide. For multi-system stacks (cameras, access control, monitoring), see integrating fog with existing security.

Frequently asked questions

How long does a security fog install take?
3-5 hours for a single-zone install on a typical retail, office, or game-room layout. Multi-zone or warehouse installs run 6-10 hours depending on the number of fog units and the wiring distance.

Can a security fog system be retrofit into an existing alarm setup?
Yes — the standard install pattern is retrofit. The fog unit connects to your existing alarm panel's programmable output. No new panel or new monitoring contract is required.

Do I need a permit for security fog installation?
Most U.S. jurisdictions don't require a building permit, but most require a one-page notification to the local fire marshal. Some states (CA, NY) require pre-install plan review. Your installer handles the paperwork in either case.

How disruptive is the install to my normal operations?
The unit mount and wiring are typically done outside business hours so customers aren't on site during the live test. Most installs are scheduled for a single evening or a slow weekday morning.