Home security has been marketed as a very simple system for years: alarms that tell you a break-in is happening, cameras that record it, and not much that actually stops someone once they’re inside. Security fog closes that gap, and it works just as well in a home as it does in the shops and warehouses it’s better known for. Read on if you want to learn how to create a simple, gold-level security system which does more than alert and record.
Smoke Screen has spent thirty years protecting commercial premises, but the underlying idea is simple enough to protect a house just as effectively: a burglar who can’t see can’t find, and can’t take, what they came for. This post explains how home security fog works, where to fit it, how it ties into the Ajax alarm you may already have, and the plug-and-play option for anyone who wants protection up and running in minutes.
The Problem With Alarms and Cameras Alone
Most home security is built around detection and recording. An alarm sounds, a camera captures footage, and an alert lands on your phone. All of that is useful, but none of it physically stops a burglary that’s already underway. In most break-ins, criminals are in and out in under 90 seconds, long before a keyholder or the police can respond.
That’s the weakness security fog is designed to remove. Instead of only telling you a break-in is happening, it acts on the intruder in the moment, filling the protected space with dense, harmless fog within 15 to 20 seconds so they simply can’t see what they’re doing. It’s like having a bouncer or security guard on your premises that actively denies entry – “Sorry sunshine, you’re not coming in here”.
How Home Security Fog Works
A security fog system connects to your alarm and, when triggered, floods a room or area with a thick, safe fog that cuts visibility to near zero in seconds and keeps it that way for over 40 minutes. A burglar who has forced their way in suddenly can’t see the jewellery, the electronics, the musical instruments, the artwork, the safe, or even the way back out. Faced with that, the overwhelming majority leave immediately and empty-handed.
The fog itself is designed to be safe. It’s non-toxic and food safe, safe for electronics and sensitive equipment, and leaves no residue, so an accidental or precautionary activation doesn’t ruin your kitchen or harm the family pet. And because a Smoke Screen unit isn’t a one-shot device, it can re-fire if needed rather than clearing after a single burst, keeping an area obscured for as long as the situation calls for.
Ajax Ready: Fire Your Fog Straight From the Ajax App
If you already run an Ajax alarm — one of the most widely installed wireless systems in the UK — this is where home security fog gets genuinely clever. Every Smoke Screen Sentinel generator is officially Ajax Ready, which is Ajax’s own certification programme. It’s not a marketing badge: the units are independently tested, approved, and listed on the Ajax Systems partner product directory.
In plain terms, Ajax Ready means the hard part is already done for you.
It comes pre-installed with the relays
Every Ajax Ready Sentinel unit ships with two Ajax Jeweller wireless relays already installed inside it, wired at the factory and powered by the unit’s own 12V supply. There’s no extra cabling, no separate power feed, and nothing additional to buy. You fit the fog machine as you normally would, and the parts that talk to your alarm are already in the box, inside the machine.
Setup is the same as any other Ajax device
Because the relays are standard Ajax Jeweller modules, adding them to your system is exactly like adding any other bit of Ajax kit:
- Fit and power the unit — wall-mount the Sentinel and connect it to the mains. The relays inside need no extra wiring.
- Add the relays in the Ajax app — open the app and add the two pre-installed relays to your Ajax hub, just as you would a door contact or motion sensor.
- Name them — label one relay “Set” (arming) and the other “Alarm” (activation) so they’re easy to manage.
- Configure and test — set them up in the app, then run a test so you can watch the fog fire on command.
Once it’s paired, the fog generator shows up in your Ajax app alongside every other device, and you control it from your phone.
What you can do from the app
This is where “Phone Fog” earns its name. From the Ajax app you can:
- See your fog generator’s status — Armed, Disarmed, or Activated — next to the rest of your Ajax devices.
- Arm and disarm it remotely from anywhere in the world.
- Trigger the fog manually after visually confirming an intruder through your Ajax camera footage.
- Set automation scenarios — choose exactly which sensors must trigger before the fog fires, so you get verified activation and no false alarms.
- Get an instant push notification the moment the fog deploys, even if your phone is on silent.
That’s the level of control that turns a fog generator from a standalone box on the wall into a fully connected part of your home security, managed from one app. You can read the full technical rundown on the Smoke Screen Ajax Ready page.
Prefer Plug-and-Play? Meet Rapid Deploy
Not everyone has an Ajax system, and not everyone wants to integrate with an alarm at all. If you want the simplest possible route to protecting a room, Rapid Deploy is the answer.
Rapid Deploy is a portable, stand-alone fog generator — think of it as a security guard you can plug in. It’s armed and disarmed with a radio key fob, so there’s no alarm system to tie into and nothing to wire. All it needs is a plug socket. No engineer, no installation appointment: you have protection up and running in about ten minutes, and you can move it around the house whenever your priorities change.
Under the bonnet it’s serious kit: a built-in dual-tech detector with a 10-metre range, a 90-second initial burst for maximum fog in the areas that matter most, fog that persists for up to 60 minutes, an energy-save mode for periods when it isn’t needed, and a 3-year warranty. It’s the easiest way to put an active layer around a home office, a room full of valuables, or a holiday let, and shift it as needed.
Take a closer look at Rapid Deploy if easy, movable protection is what you’re after.
Choosing the Right Unit for Your Home
You don’t need a warehouse-sized system to protect a house. Every Sentinel model is Ajax Ready, so the choice really comes down to how much space you want to cover, how fast, and whether you’d rather integrate with an alarm or keep it plug-and-play.
As a rule of thumb: choose Rapid Deploy if you want plug-in simplicity with no alarm; the SC20 for a targeted single zone; the S35 as the sensible default for most homes; and the S55 if you want to cover a bigger area or want the fastest, densest fill for maximum deterrence.
Where to Fit It in a Home
Fog works best when it protects the areas that matter most, rather than trying to cover the whole house. The most effective placements are the pinch points an intruder has to pass through and the rooms where your most valuable things live:
- Entryways and exit points — the doors and hallways a burglar has to use to get in and back out again.
- A main corridor — obscuring a central corridor cuts off easy movement between rooms.
- The garage — often a weak point, and frequently home to tools, bikes and vehicles.
- High-value rooms — a study or room holding artwork, musical instruments, collections or a safe.
- Anywhere valuables are concentrated — if there’s a room a burglar would head straight for, that’s a room to protect.
The principle is exactly the same as it is in commercial settings: targeted protection at the right points beats trying to blanket everything.
Home Security Fog vs a Traditional Alarm-Only Setup
To be clear, this isn’t an argument for throwing out your alarm or cameras. It’s about understanding what each part does, and where the gap is.
The takeaway is that detection and deterrence do different jobs. An alarm tells you something is wrong; fog does something about it.
Real-World Home Scenarios
- A family home with valuables in one room. An S35 or SC20 covering the study or master bedroom means that even if someone gets in, the room they’re targeting becomes impossible to work in.
- An Ajax household that wants full control. A Sentinel unit paired to the Ajax app, armed and disarmed with the rest of the system, with fog that can be fired manually after checking the camera.
- A larger, open-plan house. An S55 gives you the power to fill a big living space or a long hallway quickly, protecting several routes at once.
- A renter or a holiday let. Rapid Deploy plugs in, arms with a fob, and moves with you — no installation and no alarm required.
- A property that’s regularly empty. An automated Sentinel tied into the Ajax alarm acts without anyone present, and pings your phone the moment it fires.
Quick Tip Summary of Elite Home Protection
- Cameras and sirens are great, but they don’t help you in the moment of intrusion. You may still get robbed.
- Smoke Screen (security fog) IS safe for your home and its valuables unlike other pyrotechnic (smoke) devices that leave residue, terrible odours, and are not food safe. Don’t be cheap, or you will regret it. – We are reassuringly expensive, because we are the best.
- Smoke Screen is easy to connect to any alarm system. It just needs some sort of trigger to tell it to fire.
- Smoke Screen fog machines can be purchased with pre-installed AJAX relays (or you can fit them yourself). You can then easily control everything from your AJAX app.
- Even simpler systems like Rapid Deploy are available which literally act like an all-in-one alarm system for your home.
FAQ
Can security fog really protect a home, not just a shop?
Yes. The technology is identical; only the scale changes. A compact unit like the SC20 or S35 protects the entryways, corridors and high-value rooms of a house just as effectively as larger units protect a retail floor. An intruder who can’t see can’t find or take your valuables.
Is the fog safe for my family, pets and food?
Yes. Smoke Screen fog is non-toxic and food safe, safe for electronics and sensitive equipment, and leaves no residue. If it activates, normal visibility returns as the fog disperses, and ventilating the space speeds that up.
What does “Ajax Ready” actually mean for me?
It means every Sentinel unit arrives with two Ajax Jeweller relays already installed inside, so it connects to your Ajax hub through the app with no extra wiring. You can then see, arm, disarm and even manually trigger the fog from the Ajax app, and set which sensors must trigger before it fires.
What if I don’t have an alarm system?
Choose Rapid Deploy. It’s a stand-alone, portable unit armed with a radio key fob. Plug it into a socket and it’s protecting the room in about ten minutes — no alarm, no engineer, and you can move it around the house.
How long does the fog last, and can it fire more than once?
The fog protects the space for over 40 minutes before dispersing, and Smoke Screen units are not one-shot devices, so they can re-fire if needed rather than clearing after a single burst.
Talk to Smoke Screen
If your home security stops at detection and you’d like a layer that actually acts, we can help you work out what to protect and which unit fits.
- Book a home security assessment
- Ask which unit suits your property and layout
- See how fog ties into your Ajax alarm, or how Rapid Deploy works with no alarm at all
Ved Prakash
